Il CD di internet/CD.iso/SOURCE/N/TCPIP/NETKIT-B.05/NETKIT-B/NetKit-B-0.05/ftpd/popen.c

C/C++ Source or Header | 1994-05-23 | 4.7 KB | 165 lines

/*
 * Copyright (c) 1988 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software written by Ken Arnold and
 * published in UNIX Review, Vol. 6, No. 8.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by the University of
 *    California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#ifndef lint
/*static char sccsid[] = "from: @(#)popen.c    5.9 (Berkeley) 2/25/91";*/
static char rcsid[] = "$Id: popen.c,v 1.1 1994/05/23 09:03:47 rzsfl Exp rzsfl $";
#endif /* not lint */

#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/*
 * Special version of popen which avoids call to shell.  This insures noone
 * may create a pipe to a hidden program as a side effect of a list or dir
 * command.
 */
static int *pids;
static int fds;

FILE *
ftpd_popen(program, type)
    char *program, *type;
{
    register char *cp;
    FILE *iop;
    int argc, gargc, pdes[2], pid;
    char **pop, *argv[100], *gargv[1000], *vv[2];
    extern char **ftpglob(), **copyblk();

    if (*type != 'r' && *type != 'w' || type[1])
        return(NULL);

    if (!pids) {
        if ((fds = getdtablesize()) <= 0)
            return(NULL);
        if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
            return(NULL);
        bzero((char *)pids, fds * sizeof(int));
    }
    if (pipe(pdes) < 0)
        return(NULL);

    /* break up string into pieces */
    for (argc = 0, cp = program;; cp = NULL)
        if (!(argv[argc++] = strtok(cp, " \t\n")))
            break;

    /* glob each piece */
    gargv[0] = argv[0];
    for (gargc = argc = 1; argv[argc]; argc++) {
        argv[argc] = strdup(argv[argc]);
        if (!(pop = ftpglob(argv[argc]))) {    /* globbing failed */
            vv[0] = argv[argc];
            vv[1] = NULL;
            pop = copyblk(vv);
        }
        argv[argc] = (char *)pop;        /* save to free later */
        while (*pop && gargc < 1000)
            gargv[gargc++] = *pop++;
    }
    gargv[gargc] = NULL;

    iop = NULL;
    switch(pid = vfork()) {
    case -1:            /* error */
        (void)close(pdes[0]);
        (void)close(pdes[1]);
        goto pfree;
        /* NOTREACHED */
    case 0:                /* child */
        if (*type == 'r') {
            if (pdes[1] != 1) {
                dup2(pdes[1], 1);
                dup2(pdes[1], 2);    /* stderr, too! */
                (void)close(pdes[1]);
            }
            (void)close(pdes[0]);
        } else {
            if (pdes[0] != 0) {
                dup2(pdes[0], 0);
                (void)close(pdes[0]);
            }
            (void)close(pdes[1]);
        }
        execv(gargv[0], gargv);
        _exit(1);
    }
    /* parent; assume fdopen can't fail...  */
    if (*type == 'r') {
        iop = fdopen(pdes[0], type);
        (void)close(pdes[1]);
    } else {
        iop = fdopen(pdes[1], type);
        (void)close(pdes[0]);
    }
    pids[fileno(iop)] = pid;

pfree:    for (argc = 1; argv[argc] != NULL; argc++) {
        blkfree((char **)argv[argc]);
        free((char *)argv[argc]);
    }
    return(iop);
}

ftpd_pclose(iop)
    FILE *iop;
{
    register int fdes;
    int omask;
    union wait stat_loc;
    int pid;

    /*
     * pclose returns -1 if stream is not associated with a
     * `popened' command, or, if already `pclosed'.
     */
    if (pids == 0 || pids[fdes = fileno(iop)] == 0)
        return(-1);
    (void)fclose(iop);
    omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
    while ((pid = wait((int *)&stat_loc)) != pids[fdes] && pid != -1);
    (void)sigsetmask(omask);
    pids[fdes] = 0;
    return(pid == -1 ? -1 : stat_loc.w_status);
}