4.3BSD - /usr/src/ucb/ftp/pclose.c

   1: /*
   2:  * Copyright (c) 1980 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifndef lint
   8: static char sccsid[] = "@(#)pclose.c	1.2 (Berkeley) 3/7/86";
   9: #endif not lint
  10: 
  11: #include <stdio.h>
  12: #include <signal.h>
  13: #include <sys/param.h>
  14: #include <sys/wait.h>
  15: 
  16: #define tst(a,b)    (*mode == 'r'? (b) : (a))
  17: #define RDR 0
  18: #define WTR 1
  19: 
  20: extern  char *malloc();
  21: 
  22: static  int *popen_pid;
  23: static  int nfiles;
  24: 
  25: FILE *
  26: mypopen(cmd,mode)
  27:     char *cmd;
  28:     char *mode;
  29: {
  30:     int p[2];
  31:     int myside, hisside, pid;
  32: 
  33:     if (nfiles <= 0)
  34:         nfiles = getdtablesize();
  35:     if (popen_pid == NULL) {
  36:         popen_pid = (int *)malloc((unsigned) nfiles * sizeof *popen_pid);
  37:         if (popen_pid == NULL)
  38:             return (NULL);
  39:         for (pid = 0; pid < nfiles; pid++)
  40:             popen_pid[pid] = -1;
  41:     }
  42:     if (pipe(p) < 0)
  43:         return (NULL);
  44:     myside = tst(p[WTR], p[RDR]);
  45:     hisside = tst(p[RDR], p[WTR]);
  46:     if ((pid = vfork()) == 0) {
  47:         /* myside and hisside reverse roles in child */
  48:         (void) close(myside);
  49:         if (hisside != tst(0, 1)) {
  50:             (void) dup2(hisside, tst(0, 1));
  51:             (void) close(hisside);
  52:         }
  53:         execl("/bin/sh", "sh", "-c", cmd, (char *)NULL);
  54:         _exit(127);
  55:     }
  56:     if (pid == -1) {
  57:         (void) close(myside);
  58:         (void) close(hisside);
  59:         return (NULL);
  60:     }
  61:     popen_pid[myside] = pid;
  62:     (void) close(hisside);
  63:     return (fdopen(myside, mode));
  64: }
  65: 
  66: pabort()
  67: {
  68:     extern int mflag;
  69: 
  70:     mflag = 0;
  71: }
  72: 
  73: mypclose(ptr)
  74:     FILE *ptr;
  75: {
  76:     int child, pid, omask, pabort(), (*istat)();
  77:     union wait status;
  78: 
  79:     child = popen_pid[fileno(ptr)];
  80:     popen_pid[fileno(ptr)] = -1;
  81:     (void) fclose(ptr);
  82:     if (child == -1)
  83:         return (-1);
  84:     istat = signal(SIGINT, pabort);
  85:     omask = sigblock(sigmask(SIGQUIT)|sigmask(SIGHUP));
  86:     while ((pid = wait(&status)) != child && pid != -1)
  87:         ;
  88:     (void) sigsetmask(omask);
  89:     (void) signal(SIGINT, istat);
  90:     return (pid == -1 ? -1 : 0);
  91: }

Defined functions

Defined variables

Defined macros