C语言库函数---unix常用系统调用---使用说明(zt)

kj501 · 发表于 2004-6-9 21:31:56

[php]
函数名: kbhit
功能: 检查当前按下的键
用法: int kbhit(void);
程序例:
#include <conio.h>

int main(void)
{
cprintf("

ress any key to continue:");
while (!kbhit()) /* do nothing */ ;
cprintf("\r\nA key was pressed...\r\n");
return 0;
}

函数名: keep
功  能: 退出并继续驻留
用  法: void keep(int status, int size);
程序例:

/***NOTE:
This is an interrupt service routine.  You
can NOT compile this program with Test
Stack Overflow turned on and get an
executable file which will operate
correctly.  Due to the nature of this
function the formula used to compute
the number of paragraphs may not
necessarily work in all cases.  Use with
care!  Terminate Stay Resident (TSR)
programs are complex and no other support
for them is provided.  Refer to the
MS-DOS technical documentation
for more information.  */
#include <dos.h>
/* The clock tick interrupt */
#define INTR 0x1C
/* Screen attribute (blue on grey) */
#define ATTR 0x7900

/* reduce heaplength and stacklength
to make a smaller program in memory */
extern unsigned _heaplen = 1024;
extern unsigned _stklen  = 512;

void interrupt ( *oldhandler)(void);

void interrupt handler(void)
{
unsigned int (far *screen)[80];
static int count;

/* For a color screen the video memory
is at B800:0000.  For a monochrome
system use B000:000 */
screen = MK_FP(0xB800,0);

/* increase the counter and keep it
within 0 to 9 */
count++;
count %= 10;

/* put the number on the screen */
screen[0][79] = count + '0' + ATTR;

/* call the old interrupt handler */
oldhandler();
}

int main(void)
{

/* get the address of the current clock
tick interrupt */
oldhandler = getvect(INTR);

/* install the new interrupt handler */
setvect(INTR, handler);

/* _psp is the starting address of the
program in memory.  The top of the stack
is the end of the program.  Using _SS and
_SP together we can get the end of the
stack.  You may want to allow a bit of
saftey space to insure that enough room
is being allocated ie:
(_SS + ((_SP + safety space)/16) - _psp)
*/
keep(0, (_SS + (_SP/16) - _psp));
return 0;
}
[/php]

kj501 · 发表于 2004-6-9 21:32:49

[php]
main()主函数
每一C 程序都必须有一main()函数, 可以根据自己的爱好把它放在程序的某
个地方。有些程序员把它放在最前面, 而另一些程序员把它放在最后面, 无论放
在哪个地方, 以下几点说明都是适合的。
1. main() 参数
在Turbo C2.0启动过程中, 传递main()函数三个参数: argc, argv和env。
   * argc:  整数, 为传给main()的命令行参数个数。
   * argv:  字符串数组。
            在DOS 3.X 版本中, argv[0] 为程序运行的全路径名; 对DOS 3.0
            以下的版本, argv[0]为空串("") 。
            argv[1] 为在DOS命令行中执行程序名后的第一个字符串;
            argv[2] 为执行程序名后的第二个字符串;
            ...
            argv[argc]为NULL。
   *env:  安符串数组。env[] 的每一个元素都包含ENVVAR=value形式的字符
串。其中ENVVAR为环境变量如PATH或87。value 为ENVVAR的对应值如C:\DOS, C:
\TURBOC(对于PATH) 或YES(对于87)。
Turbo C2.0启动时总是把这三个参数传递给main()函数, 可以在用户程序中
说明(或不说明)它们, 如果说明了部分(或全部)参数, 它们就成为main()子程序
的局部变量。
请注意: 一旦想说明这些参数, 则必须按argc, argv, env 的顺序, 如以下
的例子:
   main()
   main(int argc)
   main(int argc, char *argv[])
   main(int argc, char *argv[], char *env[])
其中第二种情况是合法的, 但不常见, 因为在程序中很少有只用argc, 而不
用argv[]的情况。
以下提供一样例程序EXAMPLE.EXE,  演示如何在main()函数中使用三个参数:
   /*program name EXAMPLE.EXE*/
   #include <stdio.h>
   #include <stdlib.h>
   main(int argc, char *argv[], char *env[])
   {
      int i;
      printf("These are the %d  command- line  arguments passed  to
               main:\n\n", argc);
      for(i=0; i<=argc; i++)
         printf("argv[%d]:%s\n", i, argv);
      printf("\nThe environment string(s)on this system are:\n\n");
      for(i=0; env!=NULL; i++)
            printf(" env[%d]:%s\n", i, env);
   }
如果在DOS 提示符下, 按以下方式运行EXAMPLE.EXE:
C:\example first_argument "argument with blanks"  3  4  "last  but
one" stop!
注意: 可以用双引号括起内含空格的参数, 如本例中的: "  argument
with blanks"和"Last but one")。
结果是这样的:
   The value of argc is 7
   These are the 7 command-linearguments passed to main:
   argv[0]:C:\TURBO\EXAMPLE.EXE
   argv[1]:first_argument
   argv[2]:argument with blanks
   argv[3]:3
   argv[4]:4
   argv[5]:last but one
   argv[6]:stop!
   argv[7]NULL)
   The environment string(s) on this system are:
   env[0]: COMSPEC=C:\COMMAND.COM
   env[1]: PROMPT=$P$G          /*视具体设置而定*/
   env[2]: PATH=C:\DOS;C:\TC    /*视具体设置而定*/

   应该提醒的是: 传送main() 函数的命令行参数的最大长度为128 个字符 (包
括参数间的空格),  这是由DOS 限制的。

函数名: matherr
功  能: 用户可修改的数学错误处理程序
用  法: int matherr(struct exception *e);
程序例:

/* This is a user-defined matherr function that prevents
any error messages from being printed. */

#include<math.h>

int matherr(struct exception *a)
{
return 1;
}

函数名: memccpy
功  能: 从源source中拷贝n个字节到目标destin中
用  法: void *memccpy(void *destin, void *source, unsigned char ch,
   unsigned n);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char *src = "This is the source string";
char dest[50];
char *ptr;

ptr = memccpy(dest, src, 'c', strlen(src));

if (ptr)
{
   *ptr = '\0';
   printf("The character was found:  %s\n", dest);
}
else
   printf("The character wasn't found\n");
return 0;
}

函数名: malloc
功  能: 内存分配函数
用  法: void *malloc(unsigned size);
程序例:

#include <stdio.h>
#include <string.h>
#include <alloc.h>
#include <process.h>

int main(void)
{
char *str;

/* allocate memory for string */
/* This will generate an error when compiling */
/* with C++, use the new operator instead. */
if ((str = malloc(10)) == NULL)
{
   printf("Not enough memory to allocate buffer\n");
   exit(1);  /* terminate program if out of memory */
}

/* copy "Hello" into string */
strcpy(str, "Hello");

/* display string */
printf("String is %s\n", str);

/* free memory */
free(str);

return 0;
}

函数名: memchr
功  能: 在数组的前n个字节中搜索字符
用  法: void *memchr(void *s, char ch, unsigned n);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char str[17];
char *ptr;

strcpy(str, "This is a string");
ptr = memchr(str, 'r', strlen(str));
if (ptr)
   printf("The character 'r' is at position: %d\n", ptr - str);
else
   printf("The character was not found\n");
return 0;
}

函数名: memcpy
功  能: 从源source中拷贝n个字节到目标destin中
用  法: void *memcpy(void *destin, void *source, unsigned n);
程序例:

#include <stdio.h>
#include <string.h>
int main(void)
{
char src[] = "******************************";
char dest[] = "abcdefghijlkmnopqrstuvwxyz0123456709";
char *ptr;
printf("destination before memcpy: %s\n", dest);
ptr = memcpy(dest, src, strlen(src));
if (ptr)
   printf("destination after memcpy:  %s\n", dest);
else
   printf("memcpy failed\n");
return 0;
}

函数名: memicmp
功  能: 比较两个串s1和s2的前n个字节, 忽略大小写
用  法: int memicmp(void *s1, void *s2, unsigned n);
程序例:

#include <stdio.h>
#include <string.h>

int main(void)
{
char *buf1 = "ABCDE123";
char *buf2 = "abcde456";
int stat;
stat = memicmp(buf1, buf2, 5);
printf("The strings to position 5 are ");
if (stat)
   printf("not ");
printf("the same\n");
return 0;
}

函数名: memmove
功  能: 移动一块字节
用  法: void *memmove(void *destin, void *source, unsigned n);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
  char *dest = "abcdefghijklmnopqrstuvwxyz0123456789";
  char *src = "******************************";
  printf("destination prior to memmove: %s\n", dest);
  memmove(dest, src, 26);
  printf("destination after memmove: %s\n", dest);
  return 0;
}

函数名: memset
功  能: 设置s中的所有字节为ch, s数组的大小由n给定
用  法: void *memset(void *s, char ch, unsigned n);
程序例:

#include <string.h>
#include <stdio.h>
#include <mem.h>

int main(void)
{
char buffer[] = "Hello world\n";

printf("Buffer before memset: %s\n", buffer);
memset(buffer, '*', strlen(buffer) - 1);
printf("Buffer after memset:  %s\n", buffer);
return 0;
}

函数名: mkdir
功  能: 建立一个目录
用  法: int mkdir(char *pathname);
程序例:

#include <stdio.h>
#include <conio.h>
#include <process.h>
#include <dir.h>

int main(void)
{
  int status;

clrscr();
status = mkdir("asdfjklm");
(!status) ? (printf("Directory created\n")) :
            (printf("Unable to create directory\n"));

getch();
system("dir");
getch();

status = rmdir("asdfjklm");
(!status) ? (printf("Directory deleted\n")) :
  (perror("Unable to delete directory"));

return 0;
}

函数名: mktemp
功  能: 建立唯一的文件名
用  法: char *mktemp(char *template);
程序例:

#include <dir.h>
#include <stdio.h>

int main(void)
{
/* fname defines the template for the
   temporary file.  */

char *fname = "TXXXXXX", *ptr;

ptr = mktemp(fname);
printf("%s\n",ptr);
return 0;
}

函数名: MK_FP
功  能: 设置一个远指针
用  法: void far *MK_FP(unsigned seg, unsigned off);
程序例:

#include <dos.h>
#include <graphics.h>

int main(void)
{
int gd, gm, i;
unsigned int far *screen;

detectgraph(&gd, &gm);
if (gd == HERCMONO)
   screen = MK_FP(0xB000, 0);
else
   screen = MK_FP(0xB800, 0);
for (i=0; i<26; i++)
   screen = 0x0700 + ('a' + i);
return 0;
}

函数名: modf
功  能: 把数分为指数和尾数
用  法: double modf(double value, double *iptr);
程序例:

#include <math.h>
#include <stdio.h>

int main(void)
{
double fraction, integer;
double number = 100000.567;

fraction = modf(number, &integer);
printf("The whole and fractional parts of %lf are %lf and %lf\n",
      number, integer, fraction);
return 0;
}

函数名: movedata
功  能: 拷贝字节
用  法: void movedata(int segsrc, int offsrc, int segdest,
  int offdest, unsigned numbytes);
程序例:

#include <mem.h>

#define MONO_BASE 0xB000

/* saves the contents of the monochrome screen in buffer */
void save_mono_screen(char near *buffer)
{
movedata(MONO_BASE, 0, _DS, (unsigned)buffer, 80*25*2);
}

int main(void)
{
char buf[80*25*2];
save_mono_screen(buf);
}

函数名: moverel
功  能: 将当前位置(CP)移动一相对距离
用  法: void far moverel(int dx, int dy);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
char msg[80];

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

/* move the C.P. to location (20, 30) */
moveto(20, 30);

/* plot a pixel at the C.P. */
putpixel(getx(), gety(), getmaxcolor());

/* create and output a message at (20, 30) */
sprintf(msg, " (%d, %d)", getx(), gety());
outtextxy(20, 30, msg);

/* move to a point a relative distance */
/* away from the current value of C.P. */
moverel(100, 100);

/* plot a pixel at the C.P. */
putpixel(getx(), gety(), getmaxcolor());

/* create and output a message at C.P. */
sprintf(msg, " (%d, %d)", getx(), gety());
outtext(msg);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: movetext
功  能: 将屏幕文本从一个矩形区域拷贝到另一个矩形区域
用  法: int movetext(int left, int top, int right, int bottom,
  int newleft, int newtop);
程序例:
#include <conio.h>
#include <string.h>

int main(void)
{
char *str = "This is a test string";

clrscr();
cputs(str);
getch();

movetext(1, 1, strlen(str), 2, 10, 10);
getch();

return 0;
}

函数名: moveto
功  能: 将CP移到(x, y)
用  法: void far moveto(int x, int y);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
char msg[80];

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

/* move the C.P. to location (20, 30) */
moveto(20, 30);

/* plot a pixel at the C.P. */
putpixel(getx(), gety(), getmaxcolor());

/* create and output a message at (20, 30) */
sprintf(msg, " (%d, %d)", getx(), gety());
outtextxy(20, 30, msg);

/* move to (100, 100) */
moveto(100, 100);

/* plot a pixel at the C.P. */
putpixel(getx(), gety(), getmaxcolor());

/* create and output a message at C.P. */
sprintf(msg, " (%d, %d)", getx(), gety());
outtext(msg);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: movemem
功  能: 移动一块字节
用  法: void movemem(void *source, void *destin, unsigned len);
程序例:

#include <mem.h>
#include <alloc.h>
#include <stdio.h>
#include <string.h>

int main(void)
{
char *source = "Borland International";
char *destination;
int length;

length = strlen(source);
destination = malloc(length + 1);
movmem(source,destination,length);
printf("%s\n",destination);

return 0;
}
[/php]

kj501 · 发表于 2004-6-9 21:33:30

[php]
函数名: normvideo
功  能: 选择正常亮度字符
用  法: void normvideo(void);
程序例:

#include <conio.h>

int main(void)
{
normvideo();
cprintf("NORMAL Intensity Text\r\n");
return 0;
}

函数名: nosound
功  能: 关闭PC扬声器
用  法: void nosound(void);
程序例:

/* Emits a 7-Hz tone for 10 seconds.

   True story: 7 Hz is the resonant frequency of a chicken's skull cavity.
   This was determined empirically in Australia, where a new factory
   generating 7-Hz tones was located too close to a chicken ranch:
   When the factory started up, all the chickens died.

   Your PC may not be able to emit a 7-Hz tone.
*/

int main(void)
{
sound(7);
delay(10000);
nosound();
}
[/php]

kj501 · 发表于 2004-6-9 21:34:31

[php]
函数名: open
功  能: 打开一个文件用于读或写
用  法: int open(char *pathname, int access[, int permiss]);
程序例:
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <io.h>

int main(void)
{
int handle;
char msg[] = "Hello world";

if ((handle = open("TEST.$$$", O_CREAT | O_TEXT)) == -1)
{
   perror("Error:");
   return 1;
}
write(handle, msg, strlen(msg));
close(handle);
return 0;
}

函数名: outport
功  能: 输出整数到硬件端口中
用  法: void outport(int port, int value);
程序例:

#include <stdio.h>
#include <dos.h>

int main(void)
{
int value = 64;
int port = 0;

outportb(port, value);
printf("Value %d sent to port number %d\n", value, port);
return 0;
}

函数名: outportb
功  能: 输出字节到硬件端口中
用  法: void outportb(int port, char byte);
程序例:

#include <stdio.h>
#include <dos.h>

int main(void)
{
int value = 64;
int port = 0;

outportb(port, value);
printf("Value %d sent to port number %d\n", value, port);
return 0;
}

函数名: outtext
功  能: 在视区显示一个字符串
用  法: void far outtext(char far *textstring);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;

/* move the C.P. to the center of the screen */
moveto(midx, midy);

/* output text starting at the C.P. */
outtext("This ");
outtext("is ");
outtext("a ");
outtext("test.");

/* clean up */
getch();
closegraph();
return 0;
}

函数名: outtextxy
功  能: 在指定位置显示一字符串
用  法: void far outtextxy(int x, int y, char *textstring);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;

/* initialize graphics and local variables */
initgraph( &gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;

/* output text at the center of the screen*/
/* Note: the C.P. doesn't get changed.*/
outtextxy(midx, midy, "This is a test.");

/* clean up */
getch();
closegraph();
return 0;
}
[/php]

kj501 · 发表于 2004-6-9 21:35:27

[php]
函数名: parsfnm
功  能: 分析文件名
用  法: char *parsfnm (char *cmdline, struct fcb *fcbptr, int option);
程序例:

#include <process.h>
#include <string.h>
#include <stdio.h>
#include <dos.h>

int main(void)
{
char line[80];
struct fcb blk;

/* get file name */
printf("Enter drive and file name (no path - ie. a:file.dat)\n");
gets(line);

/* put file name in fcb */
if (parsfnm(line, &blk, 1) == NULL)
   printf("Error in parsfm call\n");
else
   printf("Drive #%d  Name: %11s\n", blk.fcb_drive, blk.fcb_name);

return 0;
}

函数名: peek
功  能: 检查存储单元
用  法: int peek(int segment, unsigned offset);
程序例:

#include <stdio.h>
#include <conio.h>
#include <dos.h>

int main(void)
{
int value = 0;

printf("The current status of your keyboard is:\n");
value = peek(0x0040, 0x0017);
if (value & 1)
   printf("Right shift on\n");
else
   printf("Right shift off\n");

if (value & 2)
   printf("Left shift on\n");
else
   printf("Left shift off\n");

if (value & 4)
   printf("Control key on\n");
else
   printf("Control key off\n");

if (value & 8)
   printf("Alt key on\n");
else
   printf("Alt key off\n");

if (value & 16)
   printf("Scroll lock on\n");
else
   printf("Scroll lock off\n");

if (value & 32)
   printf("Num lock on\n");
else
   printf("Num lock off\n");

if (value & 64)
   printf("Caps lock on\n");
else
   printf("Caps lock off\n");

return 0;
}

函数名: peekb
功  能: 检查存储单元
用  法: char peekb (int segment, unsigned offset);
程序例:

#include <stdio.h>
#include <conio.h>
#include <dos.h>

int main(void)
{
int value = 0;

printf("The current status of your keyboard is:\n");
value = peekb(0x0040, 0x0017);
if (value & 1)
   printf("Right shift on\n");
else
   printf("Right shift off\n");

if (value & 2)
   printf("Left shift on\n");
else
   printf("Left shift off\n");

if (value & 4)
   printf("Control key on\n");
else
   printf("Control key off\n");

if (value & 8)
   printf("Alt key on\n");
else
   printf("Alt key off\n");

if (value & 16)
   printf("Scroll lock on\n");
else
   printf("Scroll lock off\n");

if (value & 32)
   printf("Num lock on\n");
else
   printf("Num lock off\n");

if (value & 64)
   printf("Caps lock on\n");
else
   printf("Caps lock off\n");

return 0;
}

函数名: perror
功  能: 系统错误信息
用  法: void perror(char *string);
程序例:

#include <stdio.h>

int main(void)
{
FILE *fp;

fp = fopen("perror.dat", "r");
if (!fp)
   perror("Unable to open file for reading");
return 0;
}

函数名: pieslice
功  能: 绘制并填充一个扇形
用  法: void far pieslice(int x, int stanle, int endangle, int radius);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;
int stangle = 45, endangle = 135, radius = 100;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;

/* set fill style and draw a pie slice */
setfillstyle(EMPTY_FILL, getmaxcolor());
pieslice(midx, midy, stangle, endangle, radius);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: poke
功  能: 存值到一个给定存储单元
用  法: void poke(int segment, int offset, int value);
程序例:

#include <dos.h>
#include <conio.h>

int main(void)
{
clrscr();
cprintf("Make sure the scroll lock key is off and press any key\r\n");
getch();
poke(0x0000,0x0417,16);
cprintf("The scroll lock is now on\r\n");
return 0;
}

函数名: pokeb
功  能: 存值到一个给定存储单元
用  法: void pokeb(int segment, int offset, char value);
程序例:

#include <dos.h>
#include <conio.h>

int main(void)
{
clrscr();
cprintf("Make sure the scroll lock key is off and press any key\r\n");
getch();
pokeb(0x0000,0x0417,16);
cprintf("The scroll lock is now on\r\n");
return 0;
}

函数名: poly
功  能: 根据参数产生一个多项式
用  法: double poly(double x, int n, double c[]);
程序例:

#include <stdio.h>
#include <math.h>

/* polynomial:  x**3 - 2x**2 + 5x - 1 */

int main(void)
{
double array[] = { -1.0, 5.0, -2.0, 1.0 };
double result;

result = poly(2.0, 3, array);
printf("The polynomial: x**3 - 2.0x**2 + 5x - 1 at 2.0 is %lf\n",
         result);
return 0;
}

函数名: pow
功  能: 指数函数(x的y次方)
用  法: double pow(double x, double y);
程序例:

#include <math.h>
#include <stdio.h>

int main(void)
{
double x = 2.0, y = 3.0;

printf("%lf raised to %lf is %lf\n", x, y, pow(x, y));
return 0;
}

函数名: pow10
功  能: 指数函数(10的p次方)
用  法: double pow10(int p);
程序例:

#include <math.h>
#include <stdio.h>

int main(void)
{
double p = 3.0;

printf("Ten raised to %lf is %lf\n", p, pow10(p));
return 0;
}

函数名: printf
功  能: 产生格式化输出的函数
用  法: int printf(char *format...);
程序例:

#include <stdio.h>
#include <string.h>

#define I 555
#define R 5.5

int main(void)
{
int i,j,k,l;
char buf[7];
char *prefix = buf;
char tp[20];
printf("prefix  6d    6o    8x       10.2e       "
      "10.2f\n");
strcpy(prefix,"%");
for (i = 0; i < 2; i++)
{
   for (j = 0; j < 2; j++)
      for (k = 0; k < 2; k++)
   for (l = 0; l < 2; l++)
         {
            if (i==0)  strcat(prefix,"-");
            if (j==0)  strcat(prefix,"+");
            if (k==0)  strcat(prefix,"#");
            if (l==0)  strcat(prefix,"0");
            printf("%5s |",prefix);
            strcpy(tp,prefix);
            strcat(tp,"6d |");
            printf(tp,I);
            strcpy(tp,"");
            strcpy(tp,prefix);
            strcat(tp,"6o |");
            printf(tp,I);
            strcpy(tp,"");
            strcpy(tp,prefix);
            strcat(tp,"8x |");
            printf(tp,I);
            strcpy(tp,"");
            strcpy(tp,prefix);
      strcat(tp,"10.2e |");
      printf(tp,R);
      strcpy(tp,prefix);
      strcat(tp,"10.2f |");
      printf(tp,R);
      printf("  \n");
      strcpy(prefix,"%");
   }
   }
return 0;
}

函数名: putc
功  能: 输出一字符到指定流中
用  法: int putc(int ch, FILE *stream);
程序例:

#include <stdio.h>

int main(void)
{
char msg[] = "Hello world\n";
int i = 0;

while (msg)
   putc(msg[i++], stdout);
return 0;
}

函数名: putch
功  能: 输出字符到控制台
用  法: int putch(int ch);
程序例:

#include <stdio.h>
#include <conio.h>

int main(void)
{
char ch = 0;

printf("Input a string:");
while ((ch != '\r'))
{
   ch = getch();
   putch(ch);
}
return 0;
}

函数名: putchar
功  能: 在stdout上输出字符
用  法: int putchar(int ch);
程序例:

#include <stdio.h>

/* define some box-drawing characters */
#define LEFT_TOP  0xDA
#define RIGHT_TOP 0xBF
#define HORIZ    0xC4
#define VERT    0xB3
#define LEFT_BOT  0xC0
#define RIGHT_BOT 0xD9

int main(void)
{
char i, j;

/* draw the top of the box */
putchar(LEFT_TOP);
for (i=0; i<10; i++)
   putchar(HORIZ);
putchar(RIGHT_TOP);
putchar('\n');

/* draw the middle */
for (i=0; i<4; i++)
{
   putchar(VERT);
   for (j=0; j<10; j++)
      putchar(' ');
   putchar(VERT);
   putchar('\n');
}

/* draw the bottom */
putchar(LEFT_BOT);
for (i=0; i<10; i++)
   putchar(HORIZ);
putchar(RIGHT_BOT);
putchar('\n');

return 0;
}

函数名: putenv
功  能: 把字符串加到当前环境中
用  法: int putenv(char *envvar);
程序例:

#include <stdio.h>
#include <stdlib.h>
#include <alloc.h>
#include <string.h>
#include <dos.h>

int main(void)
{
char *path, *ptr;
int i = 0;

/* get the current path environment */
ptr = getenv("ATH");

/* set up new path */
path = malloc(strlen(ptr)+15);
strcpy(path,"ATH=");
strcat(path,ptr);
strcat(path,";c:\\temp");

/* replace the current path and display current environment */
putenv(path);
while (environ)
   printf("%s\n",environ[i++]);

return 0;
}

函数名: putimage
功  能: 在屏幕上输出一个位图
用  法: void far putimage(int x, int y, void far *bitmap, int op);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

#define ARROW_SIZE 10

void draw_arrow(int x, int y);

int main(void)
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;
void *arrow;
int x, y, maxx;
unsigned int size;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

maxx = getmaxx();
x = 0;
y = getmaxy() / 2;

/* draw the image to be grabbed */
draw_arrow(x, y);

/* calculate the size of the image */
size = imagesize(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE);

/* allocate memory to hold the image */
arrow = malloc(size);

/* grab the image */
getimage(x, y-ARROW_SIZE, x+(4*ARROW_SIZE), y+ARROW_SIZE, arrow);

/* repeat until a key is pressed */
while (!kbhit())
{
   /* erase old image */
   putimage(x, y-ARROW_SIZE, arrow, XOR_PUT);

   x += ARROW_SIZE;
   if (x >= maxx)
      x = 0;

   /* plot new image */
   putimage(x, y-ARROW_SIZE, arrow, XOR_PUT);
}

/* clean up */
free(arrow);
closegraph();
return 0;
}

void draw_arrow(int x, int y)
{
/* draw an arrow on the screen */
moveto(x, y);
linerel(4*ARROW_SIZE, 0);
linerel(-2*ARROW_SIZE, -1*ARROW_SIZE);
linerel(0, 2*ARROW_SIZE);
linerel(2*ARROW_SIZE, -1*ARROW_SIZE);
}

函数名: putpixel
功  能: 在指定位置画一像素
用  法: void far putpixel (int x, int y, int pixelcolor);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <dos.h>

#define PIXEL_COUNT 1000
#define DELAY_TIME  100  /* in milliseconds */

int main(void)
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;
int i, x, y, color, maxx, maxy, maxcolor, seed;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

maxx = getmaxx() + 1;
maxy = getmaxy() + 1;
maxcolor = getmaxcolor() + 1;

while (!kbhit())
{
   /* seed the random number generator */
   seed = random(32767);
   srand(seed);
   for (i=0; i<IXEL_COUNT; i++)
   {
  x = random(maxx);
      y = random(maxy);
      color = random(maxcolor);
      putpixel(x, y, color);
   }

   delay(DELAY_TIME);
   srand(seed);
   for (i=0; i<IXEL_COUNT; i++)
   {
  x = random(maxx);
  y = random(maxy);
  color = random(maxcolor);
  if (color == getpixel(x, y))
   putpixel(x, y, 0);
   }
}

/* clean up */
getch();
closegraph();
return 0;
}

函数名: puts
功  能: 送一字符串到流中
用  法: int puts(char *string);
程序例:

#include <stdio.h>
int main(void)
{
char string[] = "This is an example output string\n";

puts(string);
return 0;
}

函数名: puttext
功  能: 将文本从存储区拷贝到屏幕
用  法: int puttext(int left, int top, int right, int bottom, void *source);
程序例:

#include <conio.h>
int main(void)
{
char buffer[512];

/* put some text to the console */
clrscr();
gotoxy(20, 12);
cprintf("This is a test.  Press any key to continue ...");
getch();

/* grab screen contents */
gettext(20, 12, 36, 21,buffer);
clrscr();

/* put selected characters back to the screen */
gotoxy(20, 12);
puttext(20, 12, 36, 21, buffer);
getch();

return 0;
}

函数名: putw
功  能: 把一字符或字送到流中
用  法: int putw(int w, FILE *stream);
程序例:

#include <stdio.h>
#include <stdlib.h>

#define FNAME "test.$$$"

int main(void)
{
FILE *fp;
int word;

/* place the word in a file */
fp = fopen(FNAME, "wb");
if (fp == NULL)
{
   printf("Error opening file %s\n", FNAME);
   exit(1);
}

word = 94;
putw(word,fp);
if (ferror(fp))
   printf("Error writing to file\n");
else
   printf("Successful write\n");
fclose(fp);

/* reopen the file */
fp = fopen(FNAME, "rb");
if (fp == NULL)
{
   printf("Error opening file %s\n", FNAME);
   exit(1);
}

/* extract the word */
word = getw(fp);
if (ferror(fp))
   printf("Error reading file\n");
else
   printf("Successful read: word = %d\n", word);

/* clean up */
fclose(fp);
unlink(FNAME);

return 0;
}
[/php]

kj501 · 发表于 2004-6-9 21:36:33

[php]
函数名: qsort
功  能: 使用快速排序例程进行排序
用  法: void qsort(void *base, int nelem, int width, int (*fcmp)());
程序例:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int sort_function( const void *a, const void *b);

char list[5][4] = { "cat", "car", "cab", "cap", "can" };

int main(void)
{
int  x;

qsort((void *)list, 5, sizeof(list[0]), sort_function);
for (x = 0; x < 5; x++)
   printf("%s\n", list[x]);
return 0;
}

int sort_function( const void *a, const void *b)
{
return( strcmp(a,b) );
}
[/php]

kj501 · 发表于 2004-6-9 21:37:05

[php]
函数名: raise
功  能: 向正在执行的程序发送一个信号
用  法: int raise(int sig);
程序例:

#include <signal.h>

int main(void)
{
int a, b;

a = 10;
b = 0;
if (b == 0)
/* preempt divide by zero error */
   raise(SIGFPE);
a = a / b;
return 0;
}

函数名: rand
功  能: 随机数发生器
用  法: void rand(void);
程序例:

#include <stdlib.h>
#include <stdio.h>

int main(void)
{
int i;

printf("Ten random numbers from 0 to 99\n\n");
for(i=0; i<10; i++)
   printf("%d\n", rand() % 100);
return 0;
}

函数名: randbrd
功  能: 随机块读
用  法: int randbrd(struct fcb *fcbptr, int reccnt);
程序例:

#include <process.h>
#include <string.h>
#include <stdio.h>
#include <dos.h>

int main(void)
{
char far *save_dta;
char line[80], buffer[256];
struct fcb blk;
int i, result;

/* get user input file name for dta */
printf("Enter drive and file name (no path - i.e. a:file.dat)\n");
gets(line);

/* put file name in fcb */
if (!parsfnm(line, &blk, 1))
{
   printf("Error in call to parsfnm\n");
   exit(1);
}
printf("Drive #%d  File: %s\n\n", blk.fcb_drive, blk.fcb_name);

/* open file with DOS FCB open file */
bdosptr(0x0F, &blk, 0);

/* save old dta, and set new one */
save_dta = getdta();
setdta(buffer);

/* set up info for the new dta */
blk.fcb_recsize = 128;
blk.fcb_random = 0L;
result = randbrd(&blk, 1);

/* check results from randbrd */
if (!result)
   printf("Read OK\n\n");
else
{
   perror("Error during read");
   exit(1);
}

/* read in data from the new dta */
printf("The first 128 characters are:\n");
for (i=0; i<128; i++)
   putchar(buffer);

/* restore previous dta */
setdta(save_dta);

return 0;
}

函数名: randbwr
功  能: 随机块写
用  法: int randbwr(struct fcp *fcbptr, int reccnt);
程序例:

#include <process.h>
#include <string.h>
#include <stdio.h>
#include <dos.h>

int main(void)
{
char far *save_dta;
char line[80];
char buffer[256] = "RANDBWR test!";
struct fcb blk;
int result;

/* get new file name from user */
printf("Enter a file name to create (no path - ie. a:file.dat\n");
gets(line);

/* parse the new file name to the dta */
parsfnm(line,&blk,1);
printf("Drive #%d  File: %s\n", blk.fcb_drive, blk.fcb_name);

/* request DOS services to create file */
if (bdosptr(0x16, &blk, 0) == -1)
{
   perror("Error creating file");
   exit(1);
}

/* save old dta and set new dta */
save_dta = getdta();
setdta(buffer);

/* write new records */
blk.fcb_recsize = 256;
blk.fcb_random = 0L;
result = randbwr(&blk, 1);

if (!result)
   printf("Write OK\n");
else
{
   perror("Disk error");
   exit(1);
}

/* request DOS services to close the file */
if (bdosptr(0x10, &blk, 0) == -1)
{
   perror("Error closing file");
   exit(1);
}

/* reset the old dta */
setdta(save_dta);

return 0;
}

函数名: random
功  能: 随机数发生器
用  法: int random(int num);
程序例:

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

/* prints a random number in the range 0 to 99 */
int main(void)
{
randomize();
printf("Random number in the 0-99 range: %d\n", random (100));
return 0;
}

函数名: randomize
功  能: 初始化随机数发生器
用  法: void randomize(void);
程序例:

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

int main(void)
{
int i;

randomize();
printf("Ten random numbers from 0 to 99\n\n");
for(i=0; i<10; i++)
   printf("%d\n", rand() % 100);
return 0;
}

函数名: read
功  能: 从文件中读
用  法: int read(int handle, void *buf, int nbyte);
程序例:

#include <stdio.h>
#include <io.h>
#include <alloc.h>
#include <fcntl.h>
#include <process.h>
#include <sys\stat.h>

int main(void)
{
void *buf;
int handle, bytes;

buf = malloc(10);

/*
Looks for a file in the current directory named TEST.$$$ and attempts
to read 10 bytes from it.  To use this example you should create the
file TEST.$$$
*/
if ((handle =
   open("TEST.$$$", O_RDONLY | O_BINARY, S_IWRITE | S_IREAD)) == -1)
{
   printf("Error Opening File\n");
   exit(1);
}

if ((bytes = read(handle, buf, 10)) == -1) {
   printf("Read Failed.\n");
   exit(1);
}
else {
   printf("Read: %d bytes read.\n", bytes);
}
return 0;
}

函数名: realloc
功  能: 重新分配主存
用  法: void *realloc(void *ptr, unsigned newsize);
程序例:

#include <stdio.h>
#include <alloc.h>
#include <string.h>

int main(void)
{
char *str;

/* allocate memory for string */
str = malloc(10);

/* copy "Hello" into string */
strcpy(str, "Hello");

printf("String is %s\n  Address is %p\n", str, str);
str = realloc(str, 20);
printf("String is %s\n  New address is %p\n", str, str);

/* free memory */
free(str);

return 0;
}

函数名: rectangle
功  能: 画一个矩形
用  法: void far rectangle(int left, int top, int right, int bottom);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int left, top, right, bottom;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

left = getmaxx() / 2 - 50;
top = getmaxy() / 2 - 50;
right = getmaxx() / 2 + 50;
bottom = getmaxy() / 2 + 50;

/* draw a rectangle */
rectangle(left,top,right,bottom);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: registerbgidriver
功  能: 登录已连接进来的图形驱动程序代码
用  法: int registerbgidriver(void(*driver)(void));
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;

/* register a driver that was added into graphics.lib */
errorcode = registerbgidriver(EGAVGA_driver);

/* report any registration errors */
if (errorcode < 0)
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

/* draw a line */
line(0, 0, getmaxx(), getmaxy());

/* clean up */
getch();
closegraph();
return 0;
}

函数名: remove
功  能: 删除一个文件
用  法: int remove(char *filename);
程序例:

#include <stdio.h>

int main(void)
{
char file[80];

/* prompt for file name to delete */
printf("File to delete: ");
gets(file);

/* delete the file */
if (remove(file) == 0)
   printf("Removed %s.\n",file);
else
   perror("remove");

return 0;
}

函数名: rename
功  能: 重命名文件
用  法: int rename(char *oldname, char *newname);
程序例:

#include <stdio.h>

int main(void)
{
char oldname[80], newname[80];

/* prompt for file to rename and new name */
printf("File to rename: ");
gets(oldname);
printf("New name: ");
gets(newname);

/* Rename the file */
if (rename(oldname, newname) == 0)
   printf("Renamed %s to %s.\n", oldname, newname);
else
   perror("rename");

return 0;
}

函数名: restorecrtmode
功  能: 将屏幕模式恢复为先前的imitgraph设置
用  法: void far restorecrtmode(void);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int x, y;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

x = getmaxx() / 2;
y = getmaxy() / 2;

/* output a message */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(x, y, "ress any key to exit graphics:");
getch();

/* restore system to text mode */
restorecrtmode();
printf("We're now in text mode.\n");
printf("ress any key to return to graphics mode:");
getch();

/* return to graphics mode */
setgraphmode(getgraphmode());

/* output a message */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(x, y, "We're back in graphics mode.");
outtextxy(x, y+textheight("W"), "ress any key to halt:");

/* clean up */
getch();
closegraph();
return 0;
}

函数名: rewind
功  能: 将文件指针重新指向一个流的开头
用  法: int rewind(FILE *stream);
程序例:

#include <stdio.h>
#include <dir.h>

int main(void)
{
FILE *fp;
char *fname = "TXXXXXX", *newname, first;

newname = mktemp(fname);
fp = fopen(newname,"w+");
fprintf(fp,"abcdefghijklmnopqrstuvwxyz");
rewind(fp);
fscanf(fp,"%c",&first);
printf("The first character is: %c\n",first);
fclose(fp);
remove(newname);

return 0;
}

函数名: rmdir
功  能: 删除DOS文件目录
用  法: int rmdir(char *stream);
程序例:

#include <stdio.h>
#include <conio.h>
#include <process.h>
#include <dir.h>

#define DIRNAME "testdir.$$$"

int main(void)
{
int stat;

stat = mkdir(DIRNAME);
if (!stat)
      printf("Directory created\n");
else
{
   printf("Unable to create directory\n");
   exit(1);
}

getch();
system("dir/p");
getch();

stat = rmdir(DIRNAME);
if (!stat)
      printf("\nDirectory deleted\n");
else
{
perror("\nUnable to delete directory\n");
   exit(1);
}

return 0;
}
[/php]

kj501 · 发表于 2004-6-9 21:38:53

[php]
函数名: sbrk
功  能: 改变数据段空间位置
用  法: char *sbrk(int incr);
程序例:

#include <stdio.h>
#include <alloc.h>

int main(void)
{
printf("Changing allocation with sbrk()\n");
printf("Before sbrk() call: %lu bytes free\n",
(unsigned long) coreleft());
sbrk(1000);
printf(" After sbrk() call: %lu bytes free\n",
(unsigned long) coreleft());
return 0;
}

函数名: scanf
功  能: 执行格式化输入
用  法: int scanf(char *format[,argument,...]);
程序例:

#include <stdio.h>
#include <conio.h>

int main(void)
{
char label[20];
char name[20];
int entries = 0;
int loop, age;
double salary;

struct Entry_struct
{
   char  name[20];
   int age;
   float salary;
} entry[20];

/* Input a label as a string of characters restricting to 20 characters */
printf("\n\nPlease enter a label for the chart: ");
scanf("%20s", label);
fflush(stdin);  /* flush the input stream in case of bad input */

/* Input number of entries as an integer */
printf("How many entries will there be? (less than 20) ");
scanf("%d", &entries);
fflush(stdin); /* flush the input stream in case of bad input */

/* input a name restricting input to only letters upper or lower case */
for (loop=0;loop<entries;++loop)
{
   printf("Entry %d\n", loop);
   printf("  Name : ");
   scanf("%[A-Za-z]", entry[loop].name);
   fflush(stdin);  /* flush the input stream in case of bad input */

/* input an age as an integer */
   printf("  Age : ");
   scanf("%d", &entry[loop].age);
   fflush(stdin);  /* flush the input stream in case of bad input */

/* input a salary as a float */
   printf("  Salary : ");
   scanf("%f", &entry[loop].salary);
   fflush(stdin); /* flush the input stream in case of bad input */
}

/* Input a name, age and salary as a string, integer, and double */
printf("\nPlease enter your name, age and salary\n");
scanf("%20s %d %lf", name, &age, &salary);

/* Print out the data that was input */
printf("\n\nTable %s\n",label);
printf("Compiled by %s  age %d  $%15.2lf\n", name, age, salary);
printf("-----------------------------------------------------\n");
for (loop=0;loop<entries;++loop)
   printf("%4d | %-20s | %5d | %15.2lf\n",
      loop + 1,
  entry[loop].name,
  entry[loop].age,
      entry[loop].salary);
printf("-----------------------------------------------------\n");
return 0;
}

函数名: searchpath
功  能: 搜索DOS路径
用  法: char *searchpath(char *filename);
程序例:

#include <stdio.h>
#include <dir.h>

int main(void)
{
char *p;

/* Looks for TLINK and returns a pointer
   to the path  */
p = searchpath("TLINK.EXE");
printf("Search for TLINK.EXE : %s\n", p);

/* Looks for non-existent file  */
p = searchpath("NOTEXIST.FIL");
printf("Search for NOTEXIST.FIL : %s\n", p);

return 0;
}

函数名: sector
功  能: 画并填充椭圆扇区
用  法: void far sector(int x, int y, int stangle, int endangle);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy, i;
int stangle = 45, endangle = 135;
int xrad = 100, yrad = 50;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;

/* loop through the fill patterns */
for (i=EMPTY_FILL; i<USER_FILL; i++)
{
   /* set the fill style */
   setfillstyle(i, getmaxcolor());

   /* draw the sector slice */
   sector(midx, midy, stangle, endangle, xrad, yrad);

   getch();
}

/* clean up */
closegraph();
return 0;
}

函数名: segread
功  能: 读段寄存器值
用  法: void segread(struct SREGS *segtbl);
程序例:

#include <stdio.h>
#include <dos.h>

int main(void)
{
struct SREGS segs;

segread(&segs);
printf("Current segment register settings\n\n");
printf("CS: %X DS: %X\n", segs.cs, segs.ds);
printf("ES: %X SS: %X\n", segs.es, segs.ss);

return 0;
}

函数名: setactivepage
功  能: 设置图形输出活动页
用  法: void far setactivepage(int pagenum);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* select a driver and mode that supports */
/* multiple pages.                      */
int gdriver = EGA, gmode = EGAHI, errorcode;
int x, y, ht;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

x = getmaxx() / 2;
y = getmaxy() / 2;
ht = textheight("W");

/*  select the off screen page for drawing */
setactivepage(1);

/* draw a line on page #1 */
line(0, 0, getmaxx(), getmaxy());

/* output a message on page #1 */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(x, y, "This is page #1:");
outtextxy(x, y+ht, "

ress any key to halt:");

/* select drawing to page #0 */
setactivepage(0);

/* output a message on page #0 */
outtextxy(x, y, "This is page #0.");
outtextxy(x, y+ht, "

ress any key to view page #1:");
getch();

/* select page #1 as the visible page */
setvisualpage(1);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: setallpallette
功  能: 按指定方式改变所有的调色板颜色
用  法: void far setallpallette(struct palette, far *pallette);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
struct palettetype pal;
int color, maxcolor, ht;
int y = 10;
char msg[80];

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

maxcolor = getmaxcolor();
ht = 2 * textheight("W");

/* grab a copy of the palette */
getpalette(&pal);

/* display the default palette colors */
for (color=1; color<=maxcolor; color++)
{
   setcolor(color);
   sprintf(msg, "Color: %d", color);
   outtextxy(1, y, msg);
   y += ht;
}

/* wait for a key */
getch();

/* black out the colors one by one */
for (color=1; color<=maxcolor; color++)
{
   setpalette(color, BLACK);
   getch();
}

/* restore the palette colors */
setallpalette(&pal);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: setaspectratio
功  能: 设置图形纵横比
用  法: void far setaspectratio(int xasp, int yasp);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int xasp, yasp, midx, midy;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;
setcolor(getmaxcolor());

/* get current aspect ratio settings */
getaspectratio(&xasp, &yasp);

/* draw normal circle */
circle(midx, midy, 100);
getch();

/* claer the screen */
cleardevice();

/* adjust the aspect for a wide circle */
setaspectratio(xasp/2, yasp);
circle(midx, midy, 100);
getch();

/* adjust the aspect for a narrow circle */
cleardevice();
setaspectratio(xasp, yasp/2);
circle(midx, midy, 100);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: setbkcolor
功  能: 用调色板设置当前背景颜色
用  法: void far setbkcolor(int color);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* select a driver and mode that supports */
/* multiple background colors.          */
int gdriver = EGA, gmode = EGAHI, errorcode;
int bkcol, maxcolor, x, y;
char msg[80];

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

/* maximum color index supported */
maxcolor = getmaxcolor();

/* for centering text messages */
settextjustify(CENTER_TEXT, CENTER_TEXT);
x = getmaxx() / 2;
y = getmaxy() / 2;

/* loop through the available colors */
for (bkcol=0; bkcol<=maxcolor; bkcol++)
{
   /* clear the screen */
   cleardevice();

   /* select a new background color */
   setbkcolor(bkcol);

   /* output a messsage */
   if (bkcol == WHITE)
  setcolor(EGA_BLUE);
   sprintf(msg, "Background color: %d", bkcol);
   outtextxy(x, y, msg);
   getch();
}

/* clean up */
closegraph();
return 0;
}

函数名: setblock
功  能: 修改先前已分配的DOS存储段大小
用  法: int setblock(int seg, int newsize);
程序例:

#include <dos.h>
#include <alloc.h>
#include <stdio.h>
#include <stdlib.h>

int main(void)
{
unsigned int size, segp;
int stat;

size = 64; /* (64 x 16) = 1024 bytes */
stat = allocmem(size, &segp);
if (stat == -1)
   printf("Allocated memory at segment: %X\n", segp);
else
{
   printf("Failed: maximum number of paragraphs available is %d\n",
   stat);
   exit(1);
}

stat = setblock(segp, size * 2);
if (stat == -1)
   printf("Expanded memory block at segment: %X\n", segp);
else
   printf("Failed: maximum number of paragraphs available is %d\n",
         stat);

freemem(segp);

return 0;
}

函数名: setbuf
功  能: 把缓冲区与流相联
用  法: void setbuf(FILE *steam, char *buf);
程序例:

#include <stdio.h>

/* BUFSIZ is defined in stdio.h */
char outbuf[BUFSIZ];

int main(void)
{
/* attach a buffer to the standard output stream */
setbuf(stdout, outbuf);

/* put some characters into the buffer */
puts("This is a test of buffered output.\n\n");
puts("This output will go into outbuf\n");
puts("and won't appear until the buffer\n");
puts("fills up or we flush the stream.\n");

/* flush the output buffer */
fflush(stdout);

return 0;
}

函数名: setcbrk
功  能: 设置Control-break
用  法: int setcbrk(int value);
程序例:

#include <dos.h>
#include <conio.h>
#include <stdio.h>

int main(void)
{
int break_flag;

printf("Enter 0 to turn control break off\n");
printf("Enter 1 to turn control break on\n");

break_flag = getch() - 0;

setcbrk(break_flag);

if (getcbrk())
   printf("Cntrl-brk flag is on\n");
else
   printf("Cntrl-brk flag is off\n");
return 0;
}

函数名: setcolor
功  能: 设置当前画线颜色
用  法: void far setcolor(int color);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* select a driver and mode that supports */
/* multiple drawing colors.             */
int gdriver = EGA, gmode = EGAHI, errorcode;
int color, maxcolor, x, y;
char msg[80];

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

/* maximum color index supported */
maxcolor = getmaxcolor();

/* for centering text messages */
settextjustify(CENTER_TEXT, CENTER_TEXT);
x = getmaxx() / 2;
y = getmaxy() / 2;

/* loop through the available colors */
for (color=1; color<=maxcolor; color++)
{
   /* clear the screen */
   cleardevice();

   /* select a new background color */
   setcolor(color);

   /* output a messsage */
   sprintf(msg, "Color: %d", color);
   outtextxy(x, y, msg);
   getch();
}

/* clean up */
closegraph();
return 0;
}

函数名: setdate
功  能: 设置DOS日期
用  法: void setdate(struct date *dateblk);
程序例:

#include <stdio.h>
#include <process.h>
#include <dos.h>

int main(void)
{
struct date reset;
struct date save_date;

getdate(&save_date);
printf("Original date:\n");
system("date");

reset.da_year = 2001;
reset.da_day = 1;
reset.da_mon = 1;
setdate(&reset);

printf("Date after setting:\n");
system("date");

setdate(&save_date);
printf("Back to original date:\n");
system("date");

return 0;
}

函数名: setdisk
功  能: 设置当前磁盘驱动器
用  法: int setdisk(int drive);
程序例:

#include <stdio.h>
#include <dir.h>

int main(void)
{
int save, disk, disks;

/* save original drive */
save = getdisk();

/* print number of logic drives */
disks = setdisk(save);
printf("%d logical drives on the system\n\n", disks);

/* print the drive letters available */
printf("Available drives:\n");
for (disk = 0;disk < 26;++disk)
{
   setdisk(disk);
   if (disk == getdisk())
      printf("%c: drive is available\n", disk + 'a');
}
setdisk(save);

return 0;
}

函数名: setdta
功  能: 设置磁盘传输区地址
用  法: void setdta(char far *dta);
程序例:

#include <process.h>
#include <string.h>
#include <stdio.h>
#include <dos.h>

int main(void)
{
char line[80], far *save_dta;
char buffer[256] = "SETDTA test!";
struct fcb blk;
int result;

/* get new file name from user */
printf("Enter a file name to create:");
gets(line);

/* parse the new file name to the dta */
parsfnm(line, &blk, 1);
printf("%d %s\n", blk.fcb_drive, blk.fcb_name);

/* request DOS services to create file */
if (bdosptr(0x16, &blk, 0) == -1)
{
   perror("Error creating file");
   exit(1);
}

/* save old dta and set new dta */
save_dta = getdta();
setdta(buffer);

/* write new records */
blk.fcb_recsize = 256;
blk.fcb_random = 0L;
result = randbwr(&blk, 1);
printf("result = %d\n", result);

if (!result)
   printf("Write OK\n");
else
{
   perror("Disk error");
   exit(1);
}

/* request DOS services to close the file */
if (bdosptr(0x10, &blk, 0) == -1)
{
   perror("Error closing file");
   exit(1);
}

/* reset the old dta */
setdta(save_dta);
return 0;
}

函数名: setfillpattern
功  能: 选择用户定义的填充模式
用  法: void far setfillpattern(char far *upattern, int color);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int maxx, maxy;

/* a user defined fill pattern */
char pattern[8] = {0x00, 0x70, 0x20, 0x27, 0x24, 0x24, 0x07, 0x00};

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

maxx = getmaxx();
maxy = getmaxy();
setcolor(getmaxcolor());

/* select a user defined fill pattern */
setfillpattern(pattern, getmaxcolor());

/* fill the screen with the pattern */
bar(0, 0, maxx, maxy);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: setfillstyle
功  能: 设置填充模式和颜色
用  法: void far setfillstyle(int pattern, int color);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <conio.h>

/* the names of the fill styles supported */
char *fname[] = { "EMPTY_FILL",
               "SOLID_FILL",
               "LINE_FILL",
               "LTSLASH_FILL",
               "SLASH_FILL",
               "BKSLASH_FILL",
               "LTBKSLASH_FILL",
"HATCH_FILL",
               "XHATCH_FILL",
               "INTERLEAVE_FILL",
               "WIDE_DOT_FILL",
               "CLOSE_DOT_FILL",
"USER_FILL"
            };

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int style, midx, midy;
char stylestr[40];

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;

for (style = EMPTY_FILL; style < USER_FILL; style++)
{
   /* select the fill style */
   setfillstyle(style, getmaxcolor());

   /* convert style into a string */
   strcpy(stylestr, fname[style]);

   /* fill a bar */
   bar3d(0, 0, midx-10, midy, 0, 0);

   /* output a message */
   outtextxy(midx, midy, stylestr);

   /* wait for a key */
   getch();
   cleardevice();
}

/* clean up */
getch();
closegraph();
return 0;
}

函数名: setftime
功  能: 设置文件日期和时间
用  法: int setftime(int handle, struct ftime *ftimep);
程序例:

#include <stdio.h>
#include <process.h>
#include <fcntl.h>
#include <io.h>

int main(void)
{
struct ftime filet;
FILE *fp;

if ((fp = fopen("TEST.$$$", "w")) == NULL)
{
   perror("Error:");
   exit(1);
}

fprintf(fp, "testing...\n");

/* load ftime structure with new time and date */
filet.ft_tsec = 1;
filet.ft_min = 1;
filet.ft_hour = 1;
filet.ft_day = 1;
filet.ft_month = 1;
filet.ft_year = 21;

/* show current directory for time and date */
system("dir TEST.$$$");

/* change the time and date stamp*/
setftime(fileno(fp), &filet);

/* close and remove the temporary file */
fclose(fp);

system("dir TEST.$$$");

unlink("TEST.$$$");
return 0;
}

函数名: setgraphbufsize
功  能: 改变内部图形缓冲区的大小
用  法: unsigned far setgraphbufsize(unsigned bufsize);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

#define BUFSIZE 1000 /* internal graphics buffer size */

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int x, y, oldsize;
char msg[80];

/* set the size of the internal graphics buffer */
/* before making a call to initgraph.          */
oldsize = setgraphbufsize(BUFSIZE);

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("Press any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

x = getmaxx() / 2;
y = getmaxy() / 2;

/* output some messages */
sprintf(msg, "Graphics buffer size: %d", BUFSIZE);
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(x, y, msg);
sprintf(msg, "Old graphics buffer size: %d", oldsize);
outtextxy(x, y+textheight("W"), msg);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: setgraphmode
功  能: 将系统设置成图形模式且清屏
用  法: void far setgraphmode(int mode);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int x, y;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("Press any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

x = getmaxx() / 2;
y = getmaxy() / 2;

/* output a message */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(x, y, "Press any key to exit graphics:");
getch();

/* restore system to text mode */
restorecrtmode();
printf("We're now in text mode.\n");
printf("Press any key to return to graphics mode:");
getch();

/* return to graphics mode */
setgraphmode(getgraphmode());

/* output a message */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(x, y, "We're back in graphics mode.");
outtextxy(x, y+textheight("W"), "Press any key to halt:");

/* clean up */
getch();
closegraph();
return 0;
}

[/php]

kj501 · 发表于 2004-6-9 21:39:38

[php]
函数名: setjmp
功  能: 非局部转移
用  法: int setjmp(jmp_buf env);
程序例:

#include <stdio.h>
#include <process.h>
#include <setjmp.h>

void subroutine(void);

jmp_buf jumper;

int main(void)
{
int value;

value = setjmp(jumper);
if (value != 0)
{
   printf("Longjmp with value %d\n", value);
   exit(value);
}
printf("About to call subroutine ... \n");
subroutine();
return 0;
}

void subroutine(void)
{
longjmp(jumper,1);
}

函数名: setlinestyle
功  能: 设置当前画线宽度和类型
用  法: void far setlinestyle(int linestype, unsigned upattern);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <conio.h>

/* the names of the line styles supported */
char *lname[] = {
"SOLID_LINE",
"DOTTED_LINE",
"CENTER_LINE",
"DASHED_LINE",
"USERBIT_LINE"
};

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;

int style, midx, midy, userpat;
char stylestr[40];

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;

/* a user defined line pattern */
/* binary: "0000000000000001"  */
userpat = 1;

for (style=SOLID_LINE; style<=USERBIT_LINE; style++)
{
   /* select the line style */
   setlinestyle(style, userpat, 1);

   /* convert style into a string */
   strcpy(stylestr, lname[style]);

   /* draw a line */
   line(0, 0, midx-10, midy);

   /* draw a rectangle */
   rectangle(0, 0, getmaxx(), getmaxy());

   /* output a message */
   outtextxy(midx, midy, stylestr);

   /* wait for a key */
   getch();
   cleardevice();
}

/* clean up */
closegraph();
return 0;
}

函数名: setmem
功  能: 存值到存储区
用  法: void setmem(void *addr, int len, char value);
程序例:

#include <stdio.h>
#include <alloc.h>
#include <mem.h>

int main(void)
{
char *dest;

dest = calloc(21, sizeof(char));
setmem(dest, 20, 'c');
printf("%s\n", dest);

return 0;
}

函数名: setmode
功  能: 设置打开文件方式
用  法: int setmode(int handle, unsigned mode);
程序例:

#include <stdio.h>
#include <fcntl.h>
#include <io.h>

int main(void)
{
int result;

result = setmode(fileno(stdprn), O_TEXT);
if (result == -1)
   perror("Mode not available\n");
else
   printf("Mode successfully switched\n");
return 0;
}

函数名: setpalette
功  能: 改变调色板的颜色
用  法: void far setpalette(int index, int actural_color);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int color, maxcolor, ht;
int y = 10;
char msg[80];

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

maxcolor = getmaxcolor();
ht = 2 * textheight("W");

/* display the default colors */
for (color=1; color<=maxcolor; color++)
{
   setcolor(color);
   sprintf(msg, "Color: %d", color);
   outtextxy(1, y, msg);
   y += ht;
}

/* wait for a key */
getch();

/* black out the colors one by one */
for (color=1; color<=maxcolor; color++)
{
   setpalette(color, BLACK);
   getch();
}

/* clean up */
closegraph();
return 0;
}

函数名: setrgbpalette
功  能: 定义IBM8514图形卡的颜色
用  法: void far setrgbpalette(int colornum, int red, int green, int blue);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* select a driver and mode that supports the use */
/* of the setrgbpalette function.                */
int gdriver = VGA, gmode = VGAHI, errorcode;
struct palettetype pal;
int i, ht, y, xmax;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("

ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

/* grab a copy of the palette */
getpalette(&pal);

/* create gray scale */
for (i=0; i<pal.size; i++)
   setrgbpalette(pal.colors, i*4, i*4, i*4);

/* display the gray scale */
ht = getmaxy() / 16;
xmax = getmaxx();
y = 0;
for (i=0; i<pal.size; i++)
{
   setfillstyle(SOLID_FILL, i);
   bar(0, y, xmax, y+ht);
   y += ht;
}

/* clean up */
getch();
closegraph();
return 0;
}

函数名: settextjustify
功  能: 为图形函数设置文本的对齐方式
用  法: void far settextjustify(int horiz, int vert);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

/* function prototype */
void xat(int x, int y);

/* horizontal text justification settings */
char *hjust[] = { "LEFT_TEXT",
               "CENTER_TEXT",
               "RIGHT_TEXT"
            };

/* vertical text justification settings */
char *vjust[] = { "LEFT_TEXT",
"CENTER_TEXT",
"RIGHT_TEXT"
            };

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy, hj, vj;
char msg[80];

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;

/* loop through text justifications */
for (hj=LEFT_TEXT; hj<=RIGHT_TEXT; hj++)
   for (vj=LEFT_TEXT; vj<=RIGHT_TEXT; vj++)
   {
      cleardevice();
      /* set the text justification */
      settextjustify(hj, vj);

      /* create a message string */
      sprintf(msg, "%s  %s", hjust[hj], vjust[vj]);

  /* create cross hairs on the screen */
  xat(midx, midy);

      /* output the message */
      outtextxy(midx, midy, msg);
      getch();
   }

/* clean up */
closegraph();
return 0;
}

/* draw an "x" at (x, y) */
void xat(int x, int y)
{
  line(x-4, y, x+4, y);
  line(x, y-4, x, y+4);
}

函数名: settextstyle
功  能: 为图形输出设置当前的文本属性
用  法: void far settextstyle (int font, int direction, char size);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

/* the names of the text styles supported */
char *fname[] = { "DEFAULT font",
               "TRIPLEX font",
               "SMALL font",
               "SANS SERIF font",
               "GOTHIC font"
            };

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int style, midx, midy;
int size = 1;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;

settextjustify(CENTER_TEXT, CENTER_TEXT);

/* loop through the available text styles */
for (style=DEFAULT_FONT; style<=GOTHIC_FONT; style++)
{
   cleardevice();
   if (style == TRIPLEX_FONT)
      size = 4;

   /* select the text style */
   settextstyle(style, HORIZ_DIR, size);

   /* output a message */
   outtextxy(midx, midy, fname[style]);
   getch();
}

/* clean up */
closegraph();
return 0;
}

函数名: settextstyle
功  能: 为图形输出设置当前的文本属性
用  法: void far settextstyle (int font, int direction, char size);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

/* the names of the text styles supported */
char *fname[] = { "DEFAULT font",
               "TRIPLEX font",
               "SMALL font",
               "SANS SERIF font",
               "GOTHIC font"
            };

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int style, midx, midy;
int size = 1;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

midx = getmaxx() / 2;
midy = getmaxy() / 2;

settextjustify(CENTER_TEXT, CENTER_TEXT);

/* loop through the available text styles */
for (style=DEFAULT_FONT; style<=GOTHIC_FONT; style++)
{
   cleardevice();
   if (style == TRIPLEX_FONT)
      size = 4;

   /* select the text style */
   settextstyle(style, HORIZ_DIR, size);

   /* output a message */
   outtextxy(midx, midy, fname[style]);
   getch();
}

/* clean up */
closegraph();
return 0;
}

函数名: settime
功  能: 设置系统时间
用  法: void settime(struct time *timep);
程序例:

#include <stdio.h>
#include <dos.h>

int main(void)
{
struct  time t;

gettime(&t);
printf("The current minute is: %d\n", t.ti_min);
printf("The current hour is: %d\n", t.ti_hour);
printf("The current hundredth of a second is: %d\n", t.ti_hund);
printf("The current second is: %d\n", t.ti_sec);

/* Add one to the minutes struct element and then call settime  */
t.ti_min++;
settime(&t);

return 0;
}

函数名: setusercharsize
功  能: 为矢量字体改变字符宽度和高度
用  法: void far setusercharsize(int multx, int dirx, int multy, int diry);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)    /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1);                /* terminate with an error code */
}

/* select a text style */
settextstyle(TRIPLEX_FONT, HORIZ_DIR, 4);

/* move to the text starting position */
moveto(0, getmaxy() / 2);

/* output some normal text */
outtext("Norm ");

/* make the text 1/3 the normal width */
setusercharsize(1, 3, 1, 1);
outtext("Short ");

/* make the text 3 times normal width */
setusercharsize(3, 1, 1, 1);
outtext("Wide");

/* clean up */
getch();
closegraph();
return 0;
}

函数名: setvbuf
功  能: 把缓冲区与流相关
用  法: int setvbuf(FILE *stream, char *buf, int type, unsigned size);
程序例:

#include <stdio.h>

int main(void)
{
FILE *input, *output;
char bufr[512];

input = fopen("file.in", "r+b");
output = fopen("file.out", "w");

/* set up input stream for minimal disk access,
   using our own character buffer */
if (setvbuf(input, bufr, _IOFBF, 512) != 0)
   printf("failed to set up buffer for input file\n");
else
   printf("buffer set up for input file\n");

/* set up output stream for line buffering using space that
   will be obtained through an indirect call to malloc */
if (setvbuf(output, NULL, _IOLBF, 132) != 0)
   printf("failed to set up buffer for output file\n");
else
   printf("buffer set up for output file\n");

/* perform file I/O here */

/* close files */
fclose(input);
fclose(output);
return 0;
}

函数名: setvect
功  能: 设置中断矢量入口
用  法: void setvect(int intr_num, void interrupt(*isr)());
程序例:

/***NOTE:
This is an interrupt service routine.  You can NOT compile this
program with Test Stack Overflow turned on and get an executable
file which will operate correctly. */

#include <stdio.h>
#include <dos.h>
#include <conio.h>

#define INTR 0X1C /* The clock tick interrupt */

void interrupt ( *oldhandler)(void);

int count=0;

void interrupt handler(void)
{
/* increase the global counter */
count++;

/* call the old routine */
oldhandler();
}

int main(void)
{
/* save the old interrupt vector */
oldhandler = getvect(INTR);

/* install the new interrupt handler */
setvect(INTR, handler);

/* loop until the counter exceeds 20 */
while (count < 20)
   printf("count is %d\n",count);

/* reset the old interrupt handler */
setvect(INTR, oldhandler);

return 0;
}

函数名: setverify
功  能: 设置验证状态
用  法: void setverify(int value);
程序例:

#include <stdio.h>
#include <conio.h>
#include <dos.h>

int main(void)
{
int verify_flag;

printf("Enter 0 to set verify flag off\n");
printf("Enter 1 to set verify flag on\n");

verify_flag = getch() - 0;

setverify(verify_flag);

if (getverify())
   printf("DOS verify flag is on\n");
else
   printf("DOS verify flag is off\n");

return 0;
}

函数名: setviewport
功  能: 为图形输出设置当前视口
用  法: void far setviewport(int left, int top, int right,
      int bottom, int clipflag);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

#define CLIP_ON 1 /* activates clipping in viewport */

int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

setcolor(getmaxcolor());

/* message in default full-screen viewport */
outtextxy(0, 0, "* <-- (0, 0) in default viewport");

/* create a smaller viewport */
setviewport(50, 50, getmaxx()-50, getmaxy()-50, CLIP_ON);

/* display some text */
outtextxy(0, 0, "* <-- (0, 0) in smaller viewport");

/* clean up */
getch();
closegraph();
return 0;
}

函数名: setvisualpage
功  能: 设置可见图形页号
用  法: void far setvisualpage(int pagenum);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
/* select a driver and mode that supports */
/* multiple pages.                      */
int gdriver = EGA, gmode = EGAHI, errorcode;
int x, y, ht;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("ress any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

x = getmaxx() / 2;
y = getmaxy() / 2;
ht = textheight("W");

/*  select the off screen page for drawing */
setactivepage(1);

/* draw a line on page #1 */
line(0, 0, getmaxx(), getmaxy());

/* output a message on page #1 */
settextjustify(CENTER_TEXT, CENTER_TEXT);
outtextxy(x, y, "This is page #1:");
outtextxy(x, y+ht, "ress any key to halt:");

/* select drawing to page #0 */
setactivepage(0);

/* output a message  on page #0 */
outtextxy(x, y, "This is page #0.");
outtextxy(x, y+ht, "Press any key to view page #1:");
getch();

/* select page #1 as the visible page */
setvisualpage(1);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: setwritemode
功  能: 设置图形方式下画线的输出模式
用  法: void far setwritemode(int mode);
程序例:

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>

int main()
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int xmax, ymax;

/* initialize graphics and local variables */
initgraph(&gdriver, &gmode, "");

/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)  /* an error occurred */
{
   printf("Graphics error: %s\n", grapherrormsg(errorcode));
   printf("Press any key to halt:");
   getch();
   exit(1); /* terminate with an error code */
}

xmax = getmaxx();
ymax = getmaxy();

/* select XOR drawing mode */
setwritemode(XOR_PUT);

/* draw a line */
line(0, 0, xmax, ymax);
getch();

/* erase the line by drawing over it */
line(0, 0, xmax, ymax);
getch();

/* select overwrite drawing mode */
setwritemode(COPY_PUT);

/* draw a line */
line(0, 0, xmax, ymax);

/* clean up */
getch();
closegraph();
return 0;
}

函数名: signal
功  能: 设置某一信号的对应动作
用  法: int signal(int sig, sigfun fname);
程序例:

/* This example installs a signal handler routine for SIGFPE,
catches an integer overflow condition, makes an adjustment
to AX register, and returns. This example program MAY cause
your computer to crash, and will produce runtime errors
depending on which memory model is used.
*/

#pragma inline
#include <stdio.h>
#include <signal.h>

void Catcher(int sig, int type, int *reglist)
{
printf("Caught it!\n");
*(reglist + 8) = 3;          /* make return AX = 3 */
}

int main(void)
{
signal(SIGFPE, Catcher);
asm    mov    ax,07FFFH    /* AX = 32767 */
asm    inc    ax             /* cause overflow */
asm    into                   /* activate handler */

/* The handler set AX to 3 on return. If that hadn't happened,
   there would have been another exception when the next 'into'
   was executed after the 'dec' instruction. */
asm    dec    ax             /* no overflow now */
asm    into                   /* doesn't activate */
return 0;
}

函数名: sin
功  能: 正弦函数
用  法: double sin(double x);
程序例:

#include <stdio.h>
#include <math.h>

int main(void)
{
double result, x = 0.5;

result = sin(x);
printf("The sin() of %lf is %lf\n", x, result);
return 0;
}

函数名: sinh
功  能: 双曲正弦函数
用  法: double sinh(double x);
程序例:

#include <stdio.h>
#include <math.h>

int main(void)
{
double result, x = 0.5;

result = sinh(x);
printf("The hyperbolic sin() of %lf is %lf\n", x, result);
return 0;
}

函数名: sleep
功  能: 执行挂起一段时间
用  法: unsigned sleep(unsigned seconds);
程序例:

#include <dos.h>
#include <stdio.h>

int main(void)
{
int i;

for (i=1; i<5; i++)
{
   printf("Sleeping for %d seconds\n", i);
   sleep(i);
}
return 0;
}

函数名: sopen
功  能: 打开一共享文件
用  法: int sopen(char *pathname, int access, int shflag, int permiss);
程序例:

#include <io.h>
#include <fcntl.h>
#include <sys\stat.h>
#include <process.h>
#include <share.h>
#include <stdio.h>

int main(void)
{
int handle;
int status;

handle = sopen("c:\\autoexec.bat", O_RDONLY, SH_DENYNO, S_IREAD);

if (!handle)
{
   printf("sopen failed\n");
   exit(1);
}

status = access("c:\\autoexec.bat", 6);
if (status == 0)
   printf("read/write access allowed\n");
else
   printf("read/write access not allowed\n");

close(handle);
return 0;
}
[/php]

kj501 · 发表于 2004-6-9 21:44:10

[php]
函数名: sound
功  能: 以指定频率打开PC扬声器
用  法: void sound(unsigned frequency);
程序例:

/* Emits a 7-Hz tone for 10 seconds.
Your PC may not be able to emit a 7-Hz tone. */
#include <dos.h>

int main(void)
{
sound(7);
delay(10000);
nosound();
return 0;
}

函数名: spawnl
功  能: 创建并运行子程序
用  法: int spawnl(int mode, char *pathname, char *arg0,
   arg1, ... argn, NULL);
程序例:

#include <process.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
int result;

clrscr();
result = spawnl(P_WAIT, "tcc.exe", NULL);
if (result == -1)
{
   perror("Error from spawnl");
   exit(1);
}
return 0;
}

函数名: spawnle
功  能: 创建并运行子程序
用  法: int spawnle(int mode, char *pathname, char *arg0,
   arg1,..., argn, NULL);
程序例:

/* spawnle() example */

#include <process.h>
#include <stdio.h>
#include <conio.h>

int main(void)
{
int result;

clrscr();
result = spawnle(P_WAIT, "tcc.exe", NULL, NULL);
if (result == -1)
{
   perror("Error from spawnle");
   exit(1);
}
return 0;
}

函数名: sprintf
功  能: 送格式化输出到字符串中
用  法: int sprintf(char *string, char *farmat [,argument,...]);
程序例:

#include <stdio.h>
#include <math.h>

int main(void)
{
char buffer[80];

sprintf(buffer, "An approximation of Pi is %f\n", M_PI);
puts(buffer);
return 0;
}

函数名: sqrt
功  能: 计算平方根
用  法: double sqrt(double x);
程序例:

#include <math.h>
#include <stdio.h>

int main(void)
{
double x = 4.0, result;

result = sqrt(x);
printf("The square root of %lf is %lf\n", x, result);
return 0;
}

函数名: srand
功  能: 初始化随机数发生器
用  法: void srand(unsigned seed);
程序例:

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

int main(void)
{
int i;
time_t t;

srand((unsigned) time(&t));
printf("Ten random numbers from 0 to 99\n\n");
for(i=0; i<10; i++)
   printf("%d\n", rand() % 100);
return 0;
}

函数名: sscanf
功  能: 执行从字符串中的格式化输入
用  法: int sscanf(char *string, char *format[,argument,...]);
程序例:

#include <stdio.h>
#include <conio.h>

int main(void)
{
char label[20];
char name[20];
int entries = 0;
int loop, age;
double salary;

struct Entry_struct
{
   char  name[20];
   int age;
   float salary;
} entry[20];

/* Input a label as a string of characters restricting to 20 characters */
printf("\n\nPlease enter a label for the chart: ");
scanf("%20s", label);
fflush(stdin);  /* flush the input stream in case of bad input */

/* Input number of entries as an integer */
printf("How many entries will there be? (less than 20) ");
scanf("%d", &entries);
fflush(stdin); /* flush the input stream in case of bad input */

/* input a name restricting input to only letters upper or lower case */
for (loop=0;loop<entries;++loop)
{
   printf("Entry %d\n", loop);
   printf("  Name : ");
   scanf("%[A-Za-z]", entry[loop].name);
   fflush(stdin);  /* flush the input stream in case of bad input */

/* input an age as an integer */
   printf("  Age : ");
   scanf("%d", &entry[loop].age);
   fflush(stdin);  /* flush the input stream in case of bad input */

/* input a salary as a float */
   printf("  Salary : ");
   scanf("%f", &entry[loop].salary);
   fflush(stdin); /* flush the input stream in case of bad input */
}

/* Input a name, age and salary as a string, integer, and double */
printf("\nPlease enter your name, age and salary\n");
scanf("%20s %d %lf", name, &age, &salary);

/* Print out the data that was input */
printf("\n\nTable %s\n",label);
printf("Compiled by %s  age %d  $%15.2lf\n", name, age, salary);
printf("-----------------------------------------------------\n");
for (loop=0;loop<entries;++loop)
   printf("%4d | %-20s | %5d | %15.2lf\n",
      loop + 1,
  entry[loop].name,
  entry[loop].age,
  entry[loop].salary);
printf("-----------------------------------------------------\n");
return 0;
}

函数名: stat
功  能: 读取打开文件信息
用  法: int stat(char *pathname, struct stat *buff);
程序例:

#include <sys\stat.h>
#include <stdio.h>
#include <time.h>

#define FILENAME "TEST.$$$"

int main(void)
{
struct stat statbuf;
FILE *stream;

/* open a file for update */
if ((stream = fopen(FILENAME, "w+")) == NULL)
{
   fprintf(stderr, "Cannot open output file.\n");
   return(1);
}

/* get information about the file */
stat(FILENAME, &statbuf);

fclose(stream);

/* display the information returned */
if (statbuf.st_mode & S_IFCHR)
   printf("Handle refers to a device.\n");
if (statbuf.st_mode & S_IFREG)
   printf("Handle refers to an ordinary file.\n");
if (statbuf.st_mode & S_IREAD)
   printf("User has read permission on file.\n");
if (statbuf.st_mode & S_IWRITE)
   printf("User has write permission on file.\n");

printf("Drive letter of file: %c\n", 'A'+statbuf.st_dev);
printf("Size of file in bytes: %ld\n", statbuf.st_size);
printf("Time file last opened: %s\n", ctime(&statbuf.st_ctime));
return 0;
}

函数名: _status87
功  能: 取浮点状态
用  法: unsigned int _status87(void);
程序例:

#include <stdio.h>
#include <float.h>

int main(void)
{
float x;
double y = 1.5e-100;

printf("Status 87 before error: %x\n", _status87());

x = y;  /* <-- force an error to occur */
y = x;

printf("Status 87 after error : %x\n", _status87());
return 0;
}

函数名: stime
功  能: 设置时间
用  法: int stime(long *tp);
程序例:

#include <stdio.h>
#include <time.h>
#include <dos.h>

int main(void)
{
time_t t;
struct tm *area;

t = time(NULL);
area = localtime(&t);
printf("Number of seconds since 1/1/1970 is: %ld\n", t);
printf("Local time is: %s", asctime(area));

t++;
area = localtime(&t);
printf("Add a second:  %s", asctime(area));

t += 60;
area = localtime(&t);
printf("Add a minute:  %s", asctime(area));

t += 3600;
area = localtime(&t);
printf("Add an hour: %s", asctime(area));

t += 86400L;
area = localtime(&t);
printf("Add a day:    %s", asctime(area));

t += 2592000L;
area = localtime(&t);
printf("Add a month: %s", asctime(area));

t += 31536000L;
area = localtime(&t);
printf("Add a year: %s", asctime(area));
return 0;
}

函数名: stpcpy
功  能: 拷贝一个字符串到另一个
用  法: char *stpcpy(char *destin, char *source);
程序例:

#include <stdio.h>
#include <string.h>

int main(void)
{
char string[10];
char *str1 = "abcdefghi";

stpcpy(string, str1);
printf("%s\n", string);
return 0;
}

函数名: strcat
功  能: 字符串拼接函数
用  法: char *strcat(char *destin, char *source);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char destination[25];
char *blank = " ", *c = "C++", *Borland = "Borland";

strcpy(destination, Borland);
strcat(destination, blank);
strcat(destination, c);

printf("%s\n", destination);
return 0;
}

函数名: strchr
功  能: 在一个串中查找给定字符的第一个匹配之处\
用  法: char *strchr(char *str, char c);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char string[15];
char *ptr, c = 'r';

strcpy(string, "This is a string");
ptr = strchr(string, c);
if (ptr)
   printf("The character %c is at position: %d\n", c, ptr-string);
else
   printf("The character was not found\n");
return 0;
}

函数名: strcmp
功  能: 串比较
用  法: int strcmp(char *str1, char *str2);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char *buf1 = "aaa", *buf2 = "bbb", *buf3 = "ccc";
int ptr;

ptr = strcmp(buf2, buf1);
if (ptr > 0)
   printf("buffer 2 is greater than buffer 1\n");
else
   printf("buffer 2 is less than buffer 1\n");

ptr = strcmp(buf2, buf3);
if (ptr > 0)
   printf("buffer 2 is greater than buffer 3\n");
else
   printf("buffer 2 is less than buffer 3\n");

return 0;
}

函数名: strncmpi
功  能: 将一个串中的一部分与另一个串比较, 不管大小写
用  法: int strncmpi(char *str1, char *str2, unsigned maxlen);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char *buf1 = "BBB", *buf2 = "bbb";
int ptr;

ptr = strcmpi(buf2, buf1);

if (ptr > 0)
   printf("buffer 2 is greater than buffer 1\n");

if (ptr < 0)
   printf("buffer 2 is less than buffer 1\n");

if (ptr == 0)
   printf("buffer 2 equals buffer 1\n");

return 0;
}

函数名: strcpy
功  能: 串拷贝
用  法: char *strcpy(char *str1, char *str2);
程序例:

#include <stdio.h>
#include <string.h>

int main(void)
{
char string[10];
char *str1 = "abcdefghi";

strcpy(string, str1);
printf("%s\n", string);
return 0;
}

函数名: strcspn
功  能: 在串中查找第一个给定字符集内容的段
用  法: int strcspn(char *str1, char *str2);
程序例:

#include <stdio.h>
#include <string.h>
#include <alloc.h>

int main(void)
{
char *string1 = "1234567890";
char *string2 = "747DC8";
int length;

length = strcspn(string1, string2);
printf("Character where strings intersect is at position %d\n", length);

return 0;
}

函数名: strdup
功  能: 将串拷贝到新建的位置处
用  法: char *strdup(char *str);
程序例:

#include <stdio.h>
#include <string.h>
#include <alloc.h>

int main(void)
{
char *dup_str, *string = "abcde";

dup_str = strdup(string);
printf("%s\n", dup_str);
free(dup_str);

return 0;
}

函数名: stricmp
功  能: 以大小写不敏感方式比较两个串
用  法: int stricmp(char *str1, char *str2);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char *buf1 = "BBB", *buf2 = "bbb";
int ptr;

ptr = stricmp(buf2, buf1);

if (ptr > 0)
   printf("buffer 2 is greater than buffer 1\n");

if (ptr < 0)
   printf("buffer 2 is less than buffer 1\n");

if (ptr == 0)
   printf("buffer 2 equals buffer 1\n");

return 0;
}

函数名: strerror
功  能: 返回指向错误信息字符串的指针
用  法: char *strerror(int errnum);
程序例:

#include <stdio.h>
#include <errno.h>

int main(void)
{
char *buffer;
buffer = strerror(errno);
printf("Error: %s\n", buffer);
return 0;
}

函数名: strcmpi
功  能: 将一个串与另一个比较, 不管大小写
用  法: int strcmpi(char *str1, char *str2);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char *buf1 = "BBB", *buf2 = "bbb";
int ptr;

ptr = strcmpi(buf2, buf1);

if (ptr > 0)
   printf("buffer 2 is greater than buffer 1\n");

if (ptr < 0)
   printf("buffer 2 is less than buffer 1\n");

if (ptr == 0)
   printf("buffer 2 equals buffer 1\n");

return 0;
}

函数名: strncmp
功  能: 串比较
用  法: int strncmp(char *str1, char *str2, int maxlen);
程序例:

#include <string.h>
#include <stdio.h>

int  main(void)

{
char *buf1 = "aaabbb", *buf2 = "bbbccc", *buf3 = "ccc";
int ptr;

ptr = strncmp(buf2,buf1,3);
if (ptr > 0)
   printf("buffer 2 is greater than buffer 1\n");
else
   printf("buffer 2 is less than buffer 1\n");

ptr = strncmp(buf2,buf3,3);
if (ptr > 0)
   printf("buffer 2 is greater than buffer 3\n");
else
   printf("buffer 2 is less than buffer 3\n");

return(0);
}

函数名: strncmpi
功  能: 把串中的一部分与另一串中的一部分比较, 不管大小写
用  法: int strncmpi(char *str1, char *str2);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char *buf1 = "BBBccc", *buf2 = "bbbccc";
int ptr;

ptr = strncmpi(buf2,buf1,3);

if (ptr > 0)
   printf("buffer 2 is greater than buffer 1\n");

if (ptr < 0)
   printf("buffer 2 is less than buffer 1\n");

if (ptr == 0)
   printf("buffer 2 equals buffer 1\n");

return 0;
}

函数名: strncpy
功  能: 串拷贝
用  法: char *strncpy(char *destin, char *source, int maxlen);
程序例:

#include <stdio.h>
#include <string.h>

int main(void)
{
char string[10];
char *str1 = "abcdefghi";

strncpy(string, str1, 3);
string[3] = '\0';
printf("%s\n", string);
return 0;
}

函数名: strnicmp
功  能: 不注重大小写地比较两个串
用  法: int strnicmp(char *str1, char *str2, unsigned maxlen);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char *buf1 = "BBBccc", *buf2 = "bbbccc";
int ptr;

ptr = strnicmp(buf2, buf1, 3);

if (ptr > 0)
   printf("buffer 2 is greater than buffer 1\n");

if (ptr < 0)
   printf("buffer 2 is less than buffer 1\n");

if (ptr == 0)
   printf("buffer 2 equals buffer 1\n");

return 0;
}

函数名: strnset
功  能: 将一个串中的所有字符都设为指定字符
用  法: char *strnset(char *str, char ch, unsigned n);
程序例:

#include <stdio.h>
#include <string.h>

int main(void)
{
char *string = "abcdefghijklmnopqrstuvwxyz";
char letter = 'x';

printf("string before strnset: %s\n", string);
strnset(string, letter, 13);
printf("string after  strnset: %s\n", string);

return 0;
}

函数名: strpbrk
功  能: 在串中查找给定字符集中的字符
用  法: char *strpbrk(char *str1, char *str2);
程序例:

#include <stdio.h>
#include <string.h>

int main(void)
{
char *string1 = "abcdefghijklmnopqrstuvwxyz";
char *string2 = "onm";
char *ptr;

ptr = strpbrk(string1, string2);

if (ptr)
   printf("strpbrk found first character: %c\n", *ptr);
else
   printf("strpbrk didn't find character in set\n");

return 0;
}

函数名: strrchr
功  能: 在串中查找指定字符的最后一个出现
用  法: char *strrchr(char *str, char c);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char string[15];
char *ptr, c = 'r';

strcpy(string, "This is a string");
ptr = strrchr(string, c);
if (ptr)
   printf("The character %c is at position: %d\n", c, ptr-string);
else
   printf("The character was not found\n");
return 0;
}

函数名: strrev
功  能: 串倒转
用  法: char *strrev(char *str);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char *forward = "string";

printf("Before strrev(): %s\n", forward);
strrev(forward);
printf("After strrev():  %s\n", forward);
return 0;
}

函数名: strset
功  能: 将一个串中的所有字符都设为指定字符
用  法: char *strset(char *str, char c);
程序例:

#include <stdio.h>
#include <string.h>

int main(void)
{
char string[10] = "123456789";
char symbol = 'c';

printf("Before strset(): %s\n", string);
strset(string, symbol);
printf("After strset():  %s\n", string);
return 0;
}

函数名: strspn
功  能: 在串中查找指定字符集的子集的第一次出现
用  法: int strspn(char *str1, char *str2);
程序例:

#include <stdio.h>
#include <string.h>
#include <alloc.h>

int main(void)
{
char *string1 = "1234567890";
char *string2 = "123DC8";
int length;

length = strspn(string1, string2);
printf("Character where strings differ is at position %d\n", length);
return 0;
}

函数名: strstr
功  能: 在串中查找指定字符串的第一次出现
用  法: char *strstr(char *str1, char *str2);
程序例:

#include <stdio.h>
#include <string.h>

int main(void)
{
char *str1 = "Borland International", *str2 = "nation", *ptr;

ptr = strstr(str1, str2);
printf("The substring is: %s\n", ptr);
return 0;
}

函数名: strtod
功  能: 将字符串转换为double型值
用  法: double strtod(char *str, char **endptr);
程序例:

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
char input[80], *endptr;
double value;

printf("Enter a floating point number:");
gets(input);
value = strtod(input, &endptr);
printf("The string is %s the number is %lf\n", input, value);
return 0;
}

函数名: strtok
功  能: 查找由在第二个串中指定的分界符分隔开的单词
用  法: char *strtok(char *str1, char *str2);
程序例:

#include <string.h>
#include <stdio.h>

int main(void)
{
char input[16] = "abc,d";
char *p;

/* strtok places a NULL terminator
in front of the token, if found */
p = strtok(input, ",");
if (p) printf("%s\n", p);

/* A second call to strtok using a NULL
as the first parameter returns a pointer
to the character following the token  */
p = strtok(NULL, ",");
if (p) printf("%s\n", p);
return 0;
}

函数名: strtol
功  能: 将串转换为长整数
用  法: long strtol(char *str, char **endptr, int base);
程序例:

#include <stdlib.h>
#include <stdio.h>

int main(void)
{
char *string = "87654321", *endptr;
long lnumber;

/* strtol converts string to long integer  */
lnumber = strtol(string, &endptr, 10);
printf("string = %s  long = %ld\n", string, lnumber);

return 0;
}

函数名: strupr
功  能: 将串中的小写字母转换为大写字母
用  法: char *strupr(char *str);
程序例:

#include <stdio.h>
#include <string.h>

int main(void)
{
char *string = "abcdefghijklmnopqrstuvwxyz", *ptr;

/* converts string to upper case characters */
ptr = strupr(string);
printf("%s\n", ptr);
return 0;
}

函数名: swab
功  能: 交换字节
用  法: void swab (char *from, char *to, int nbytes);
程序例:

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

char source[15] = "rFna koBlrna d";
char target[15];

int main(void)
{
swab(source, target, strlen(source));
printf("This is target: %s\n", target);
return 0;
}

函数名: system
功  能: 发出一个DOS命令
用  法: int system(char *command);
程序例:

#include <stdlib.h>
#include <stdio.h>

int main(void)
{
printf("About to spawn command.com and run a DOS command\n");
system("dir");
return 0;
}
[/php]

		自动登录	找回密码
密码			注册