求各位帮忙作几道题～谢谢

loseblue

写出下列命令的功能：
1．$kill –15 4501
2．$chown –R li /home/wang
3．$who –H | grep wang
4．$ls –l a*|grep –v “*．c”
5．$write wang <fileone || mail wang <fileone&
6．$ps –ef |tee fileabc
7．$mkdir –m 640 dirabc
8．$mknod PABC P
$find / =name “a*” > PABC&
$cat <ABC
9．$ln –s Lambertfile Symlink
10．$last qq


写出下列Shell或C语言程序段完成的功能：
1．
main()
{
  int pid, i;
  int p=1;
pid=fork();
if (pid<0) {
  echo error;
  exit (1);
}
  else if (pid == 0 ) {
          execl(“/bin/ls”,”ls”,”-l”,0);
exit(1);
}
else {
for (i=1;i<=10;i++)
  {p=p*i; }
printf(“%d”,p);
}
}
2．
#filename is cp．sh
if [! –f $1]
then
  echo “cy1 is not a regular file．”
elif [! –d $2 ]
  then
      echo “cy2 is not a directory．”
  else
cp $1 $2
fi

3．
until who|grep $1 > /dev/null
do
  sleep 30
done
echo “$1用户已经登录到系统中”
exit 1
fi

4．
CURRDIR=’pwd’
until [$CURRDIR = ‘/’]
do
  CURRDIR=’pwd’
  Ls –l $CURRDIR
  Cd ．．
Done

5．
#include <unistd．h>
#include <stdlib．h>
int main()
{
char buffer[128];
int nread;
nread=read(0,buffer,128);
if(nread=-1)
  write(2,”Areaderror has occurred \n”,26);
if((write(1,buffer,nread))!=nread)
  write(2,”Awriteerror has occurred \n”,26);
exit(0);
}


谢谢各位～～

KDF2003

自己一一试验不就知道了，想偷懒吗？

自己看书看文档，或者Baidu&Google，更省事！