proc -x cshell fork()

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#define MAXLINE 10
int main(void)
{
char buf[MAXLINE];
pid_t pid;
int status;
printf("%%");
while(fgets(buf,MAXLINE,stdin)!=NULL){
    if(buf[strlen(buf)-1] == '
')
        buf[strlen(buf)-1] = 0;
if (( pid = fork()) < 0 )
    printf("fork error
");
else if (pid == 0){
    execlp(buf,buf,(char *)0);
    printf("could not execute : %s
",buf);
    exit(127);
    }
if((pid = waitpid(pid,&status,0))<0)
    printf("waitpid error
");
}
}