变量类型转换问题

sherman

代码如下：

1. #include <stdio.h>
   
2. #include <termios.h>
   
3. #include <term.h>
   
4. #include <curses.h>
   
5. #include <unistd.h>
   
6. 
   
7. static struct termios initial_settings, new_settings;
   
8. static int peek_character = -1;
   
9. 
   
10. void init_keyboard();
    
11. void close_keyboard();
    
12. int kbhit();
    
13. int readch();
    
14. 
    
15. int main()
    
16. {
    
17. int ch = 0;
    
18. 
    
19. init_keyboard();
    
20. while(ch != 'q') {
    
21. printf("looping\n");
    
22. sleep(1);
    
23. if(kbhit()) {
    
24. ch = readch();
    
25. printf("you hit %c\n",ch);
    
26. }
    
27. }
    
28. close_keyboard();
    
29. exit(0);
    
30. }
    
31. 
    
32. void init_keyboard()
    
33. {
    
34. tcgetattr(0,&initial_settings);
    
35. new_settings = initial_settings;
    
36. new_settings.c_lflag &= ~ICANON;
    
37. new_settings.c_lflag &= ~ECHO;
    
38. new_settings.c_lflag &= ~ISIG;
    
39. new_settings.c_cc[VMIN] = 1;
    
40. new_settings.c_cc[VTIME] = 0;
    
41. tcsetattr(0, TCSANOW, &new_settings);
    
42. }
    
43. 
    
44. void close_keyboard()
    
45. {
    
46. tcsetattr(0, TCSANOW, &initial_settings);
    
47. }
    
48. 
    
49. int kbhit()
    
50. {
    
51. char ch;
    
52. int nread;
    
53. 
    
54. if(peek_character != -1)
    
55. return 1;
    
56. new_settings.c_cc[VMIN]=0;
    
57. tcsetattr(0, TCSANOW, &new_settings);
    
58. nread = read(0,&ch,1);
    
59. new_settings.c_cc[VMIN]=1;
    
60. tcsetattr(0, TCSANOW, &new_settings);
    
61. 
    
62. if(nread == 1) {
    
63. peek_character = ch;
    
64. return 1;
    
65. }
    
66. return 0;
    
67. }
    
68. 
    
69. int readch()
    
70. {
    
71. char ch;
    
72. 
    
73. if(peek_character != -1) {
    
74. ch = peek_character;
    
75. peek_character = -1;
    
76. return ch;
    
77. }
    
78. read(0,&ch,1);
    
79. return ch;
    
80. }
    

复制代码

不明白为何peek_character在开始已经声明是int类型了，怎么后来还可以把字符串赋值给它？

x11

首先，这个跟你标题里的static无关吧
其次，哪里有把字符串赋值给它？

sherman

peek_character是int，ch是char，代码有一段是“peek_character = ch”，这是隐式类型转换吗？

liwangli

Post by sherman;2100721
peek_character是int，ch是char，代码有一段是“peek_character = ch”，这是隐式类型转换吗？

这样当然没有问题
话说在C中,字符常量本来就是当成int存放的,不信sizeof('a')看是结果是多少.另外类似getchar这样的函数,你去查原型到底是"int getchar(void)"还是"char getchar(void)"