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/* SYSTEM(3) - Issue a "shell" command
**
**	Copyright 1986 by Ken Harrenstien, SRI International.
**
**	This is only a partial implementation.  It assumes the first word
**	of the string argument is a program name, and invokes that
**	program with the string as its sole argument.
*/

#include "c-env.h"
#include "string.h"
#include "stdio.h"

#if !(SYS_T20+SYS_10X)
#error system() not supported for this system.
#endif

#include "frkxec.h"

int
system(s)
char *s;
{
    char *prog, *malloc();
    int proglen, res;

    proglen = strpos(s, ' ');	/* See if 1st arg ends in space */
    if (proglen < 0) prog = s;	/* No, whole string is prog name */
    else {			/* Aha, create separate string for prog name */
	if ((prog = malloc(proglen+1)) == NULL) {
	    fprintf(stderr,"\nsystem(): cannot malloc space for prog name\n");
	    return(127);
	}
	strncpy(prog, s, proglen);	/* Extract program name */
	prog[proglen] = '\0';		/* Tie off */
    }

#if CPU_PDP10
    {
	struct frkxec f;
	char *av[2];
	av[0] = s;		/* Set up fake argv array */
	av[1] = 0;
	f.fx_flags = FX_PGMSRCH | FX_WAIT;
	f.fx_name = prog;
	f.fx_argv = av;
	f.fx_envp = NULL;
	if (forkexec(&f) < 0)
	    res = 127;
	else res = f.fx_waitres;
    }

#else	/* Vanilla system */
    {
	int pid;
	if ((pid = vfork()) == 0) {	/* Fork, sharing memory for speed */
	    execlp(prog, s, NULL);	/* Invoke the program */
	    _exit(127);			/* Just exit child if invoke failed */
	}
	while (wait(&res) != pid);	/* Wait until child done */
    }
#endif

    if (proglen >= 0)		/* If allocated some mem, */
	free(prog);		/* free it up */
    return res;			/* Return result */
}