usr/src/cmd/mailx/popen.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  23 /*        All Rights Reserved   */
  24
  25
  26 /*
  27  * University Copyright- Copyright (c) 1982, 1986, 1988
  28  * The Regents of the University of California
  29  * All Rights Reserved
  30  *
  31  * University Acknowledgment- Portions of this document are derived from
  32  * software developed by the University of California, Berkeley, and its
  33  * contributors.
  34  */
  35
  36 #pragma ident   "%Z%%M% %I%     %E% SMI"
  37
  38 /*
  39  * mailx -- a modified version of a University of California at Berkeley
  40  *      mail program
  41  *
  42  * npopen() and npclose()
  43  *
  44  * stolen from C library, modified to use SHELL variable
  45  */
  46
  47
  48 #include <stdio.h>
  49 #include <signal.h>
  50 #include <fcntl.h>
  51
  52 #define tst(a,b) (*mode == 'r'? (b) : (a))
  53 #define RDR     0
  54 #define WTR     1
  55
  56 #ifdef VMUNIX
  57 #define sigset  signal
  58 #else
  59 extern void (*sigset())();
  60 #endif
  61 #ifdef preSVr4
  62 extern FILE *fdopen();
  63 extern int execlp(), fork(), pipe(), close(), fcntl();
  64 #ifndef sun
  65 typedef int pid_t;
  66 #endif
  67 #else
  68 # include <unistd.h>
  69 # include <wait.h>
  70 #endif
  71 static pid_t popen_pid[20];
  72
  73 FILE *
  74 npopen(char *cmd, char *mode)
  75 {
  76         int     p[2];
  77         register pid_t pid;
  78         register int myside, yourside;
  79         char *Shell, *value(char *);
  80
  81         if ((Shell = value("SHELL")) == NULL || *Shell=='\0')
  82 #ifdef preSVr4
  83                 Shell = "/bin/sh";
  84 #else
  85                 Shell = "/usr/bin/sh";
  86 #endif
  87         if(pipe(p) < 0)
  88                 return(NULL);
  89         myside = tst(p[WTR], p[RDR]);
  90         yourside = tst(p[RDR], p[WTR]);
  91         if((pid = fork()) == 0) {
  92                 /* myside and yourside reverse roles in child */
  93                 int     stdio;
  94
  95                 stdio = tst(0, 1);
  96                 (void) close(myside);
  97                 (void) close(stdio);
  98                 (void) fcntl(yourside, 0, stdio);
  99                 (void) close(yourside);
 100                 (void) execlp(Shell, Shell, "-c", cmd, (char *)0);
 101                 perror(Shell);
 102                 _exit(1);
 103         }
 104         if(pid == (pid_t)-1)
 105                 return(NULL);
 106         popen_pid[myside] = pid;
 107         (void) close(yourside);
 108         return(fdopen(myside, mode));
 109 }
 110
 111 int
 112 npclose(FILE *ptr)
 113 {
 114         register int f;
 115         register pid_t r;
 116         int status;
 117         void (*istat)(int), (*qstat)(int);
 118
 119         f = fileno(ptr);
 120         (void) fclose(ptr);
 121         istat = sigset(SIGINT, SIG_IGN);
 122         qstat = sigset(SIGQUIT, SIG_IGN);
 123         while((r = wait(&status)) != popen_pid[f] && r != (pid_t)-1)
 124                 ;
 125         if(r == (pid_t)-1)
 126                 status = -1;
 127         (void) sigset(SIGINT, istat);
 128         (void) sigset(SIGQUIT, qstat);
 129         return(status);
 130 }