BSD 4_4 release

[unix-history] / usr / src / usr.bin / f77 / libU77 / system_.c

/*-
* Copyright (c) 1980 The Regents of the University of California.
* All rights reserved.
*
* This module is believed to contain source code proprietary to AT&T.
* Use and redistribution is subject to the Berkeley Software License
* Agreement and your Software Agreement with AT&T (Western Electric).
*/

#ifndef lint
static char sccsid[] = "@(#)system_.c   5.4 (Berkeley) 4/12/91";
#endif /* not lint */

/*
* execute a unix command
*
* calling sequence:
*      iexit = system(command)
* where:
*      iexit will return the exit status of the command
*      command is a character string containing the command to be executed
*/

#include        "../libI77/fiodefs.h"
#include        "../libI77/f_errno.h"
#include <sys/param.h>
#ifndef NCARGS
#define NCARGS  256
#endif


long system_(s, n)
char *s;
long n;
{
       char buf[NCARGS - 50];
       long i;

       if (n >= sizeof buf)
               return(-(long)(errno=F_ERARG));
       for (i = 0; i < MXUNIT; i++)
               flush_(&i);
       g_char(s, n, buf);
       return((long)system(buf));
}

/*
* this is a sane version of the libc routine.
*/

#include <sys/signal.h>
#include <stdlib.h>
#include <string.h>

system(s)
char *s;
{
       register sig_t istat, qstat;
       int status, pid, w;
       char *shname, *shell;

       if ((shell = getenv("SHELL")) == NULL)
               shell = "/bin/sh";

       if (shname = rindex(shell, '/'))
               shname++;
       else
               shname = shell;

       if ((pid = vfork()) == 0) {
               execl(shell, shname, "-c", s, (char *)0);
               _exit(127);
       }
       if (pid == -1)
               return(-1);

       istat = signal(SIGINT, SIG_IGN);
       qstat = signal(SIGQUIT, SIG_IGN);
       while ((w = wait(&status)) != pid && w != -1)
               ;
       if (w == -1)
               status = -1;
       (void)signal(SIGINT, istat);
       (void)signal(SIGQUIT, qstat);
       return(status);
}