95 lines
1.9 KiB
C
95 lines
1.9 KiB
C
/*
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* Copyright (c) 1980 Regents of the University of California.
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* All rights reserved. The Berkeley software License Agreement
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* specifies the terms and conditions for redistribution.
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*/
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#ifndef lint
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static char sccsid[] = "@(#)pclose.c 1.1 94/10/31 SMI"; /* from UCB 1.2 3/7/86 */
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#endif not lint
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#include <stdio.h>
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#include <signal.h>
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#include <sys/param.h>
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#include <sys/wait.h>
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#include <vfork.h>
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#define tst(a,b) (*mode == 'r'? (b) : (a))
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#define RDR 0
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#define WTR 1
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extern char *malloc();
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static int *popen_pid;
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static int nfiles;
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FILE *
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mypopen(cmd,mode)
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char *cmd;
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char *mode;
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{
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int p[2];
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int myside, hisside, pid;
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if (nfiles <= 0)
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nfiles = getdtablesize();
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if (popen_pid == NULL) {
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popen_pid = (int *)malloc((unsigned) nfiles * sizeof *popen_pid);
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if (popen_pid == NULL)
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return (NULL);
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for (pid = 0; pid < nfiles; pid++)
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popen_pid[pid] = -1;
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}
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if (pipe(p) < 0)
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return (NULL);
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myside = tst(p[WTR], p[RDR]);
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hisside = tst(p[RDR], p[WTR]);
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if ((pid = vfork()) == 0) {
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/* myside and hisside reverse roles in child */
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(void) close(myside);
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if (hisside != tst(0, 1)) {
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(void) dup2(hisside, tst(0, 1));
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(void) close(hisside);
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}
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execl("/bin/sh", "sh", "-c", cmd, (char *)NULL);
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_exit(127);
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}
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if (pid == -1) {
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(void) close(myside);
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(void) close(hisside);
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return (NULL);
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}
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popen_pid[myside] = pid;
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(void) close(hisside);
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return (fdopen(myside, mode));
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}
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void
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pabort()
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{
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extern int mflag;
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mflag = 0;
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}
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mypclose(ptr)
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FILE *ptr;
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{
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int child, pid, omask;
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void pabort(), (*istat)();
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union wait status;
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child = popen_pid[fileno(ptr)];
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popen_pid[fileno(ptr)] = -1;
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(void) fclose(ptr);
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if (child == -1)
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return (-1);
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istat = signal(SIGINT, pabort);
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omask = sigblock(sigmask(SIGQUIT)|sigmask(SIGHUP));
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while ((pid = wait(&status)) != child && pid != -1)
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;
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(void) sigsetmask(omask);
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(void) signal(SIGINT, istat);
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return (pid == -1 ? -1 : 0);
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}
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