Shell-like Program (Basic implementation portion of Shell programs)

Directly on the code:

#include "apue.h" #include <sys/wait.h>int main (void) {    char    buf[maxline];/* form apue.h  4096 */    pid_t   pid;    int     status;    printf ("percent");  /* Print PROMT (printf requires percent to print%) *    /while (Fgets (buf, MAXLINE, stdin)! = NULL) {        if (Buf[strlen (BUF) -1] = = ' \ n ') {            Buf[strlen (BUF)-1] = 0;/* Replace newline while null */        }        if ((PID = fork ()) < 0) { C13/>err_sys ("fork Error");        } else if (PID = = 0) {            execlp (buf, buf, (char *) 0);            Err_ret ("couldn ' t execute:%s", buf);            Exit (127);        }        /* Parent */        if (PID = Waitpid (PID, &status, 0)) < 0) {            err_sys ("Waitpid error");        }        printf ("percent");    }    Exit (0);}

Many times do not like CSDN This code display, and then affixed to the vim

Test:

The function of this applet is that it cannot pass parameters to the command, for example, we cannot specify a directory name to list, we can only run it in the current working directory.

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Shell-like Program (Basic implementation portion of Shell programs)