shio.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char sccsid[] = "@(#)shio.c	4.1 (decvax!larry) 7/2/90";
#endif


/*******
 *	shio(cmd, fi, fo, user, fe)	execute shell of command with
 *	char *cmd, *fi, *fo, *fe;	fi, fo, fe as standard in/out/err
 *	char *user;		user name
 *
 *	return codes:
 *		0  - ok
 *		non zero -  failed  -  status from child
 */

/*******
 * Mods:
 * 	decvax!larry - touch LCK.Xfiles periodically 
 *		     - only allow MAXTOUCH touches before 
 *			aborting the command.
 *******/




/************************************************************************
 *									*
 *			Copyright (c) 1984 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/




#include "uucp.h"
#include <signal.h>
#include <errno.h>

touch_alarm();
#define MAXTOUCH  9 /* the max number of times a LCK file should be touched */
int pid;

char *tcmd;
int touch_count;
extern int errno;

shio(cmd, fi, fo, user, fe)
char *cmd, *fi, *fo, *user, *fe;
{
	int status, f;
	int uid, ret;
	char path[MAXFULLNAME];

	if (fi == NULL)
		fi = "/dev/null";
	if (fo == NULL)
		fo = "/dev/null";
	if (fe == NULL)
		fe = "/dev/null";
	tcmd = cmd;  /* so touch_alarm() knows the name of command */

	DEBUG(3, "shio - %s\n", cmd);
	if ((pid = fork()) == 0) {
		signal(SIGINT, SIG_IGN);
		signal(SIGHUP, SIG_IGN);
		signal(SIGQUIT, SIG_IGN);
		signal(SIGKILL, SIG_IGN);
		signal(SIGALRM, SIG_IGN);
		signal(SIGPIPE, SIG_IGN);
		close(Ifn);
		close(Ofn);
		close(0);
		if (user == NULL
		|| (gninfo(user, &uid, path) != 0)
		|| setuid(uid))
			setuid(getuid());
		f = open(subfile(fi), 0);
		if (f != 0) {
			ASSERT_NOFAIL(f == 0, "CANT NOT OPEN INPUT - shio", 
				subfile(fi), errno);
			exit(f);
		}
		close(1);
		f = creat(subfile(fo), 0666);
		if (f != 1) {
			ASSERT_NOFAIL(f == 1, "CANT NOT OPEN OUPUT - shio", 
				subfile(fo), errno);
			exit(f);
		}
/* sendmail does not like this ? 
		close(2);
		f = creat(subfile(fe), 0666);
		if (f != 2) {
			ASSERT_NOFAIL(f == 2, "CANT NOT OPEN ERROR - shio", 
				subfile(fe), 0);
			exit(f);
		}
*/
		execl(SHELL, "sh", "-c", cmd, 0);
		exit(100);
	}
	signal(SIGALRM, touch_alarm);
	alarm(X_LOCKTIME-500); /* to refresh lock file */
	while ((ret = wait(&status)) != pid && ret != -1);
	touch_count = 0;
	DEBUG(3, "status %d\n", status);
	alarm(0);
	return(status);
}


touch_alarm()
 {
	if (++touch_count > MAXTOUCH) {
		logent(tcmd, "command terminated - exceeded time limit");
		touch_count = 0;
		kill(pid, SIGTERM);
		return;
	}
	ultouch();
	logent("touch lock file", "cmd xqt'ing > 55 minutes");
	alarm(X_LOCKTIME-500);
	return;
 }