contrib/dialog/prgbox.c

   1 /*
   2  *  $Id: prgbox.c,v 1.15 2022/04/03 22:38:16 tom Exp $
   3  *
   4  *  prgbox.c -- implements the prg box
   5  *
   6  *  Copyright 2011-2019,2022    Thomas E. Dickey
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU Lesser General Public License, version 2.1
  10  *  as published by the Free Software Foundation.
  11  *
  12  *  This program is distributed in the hope that it will be useful, but
  13  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *  Lesser General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU Lesser General Public
  18  *  License along with this program; if not, write to
  19  *      Free Software Foundation, Inc.
  20  *      51 Franklin St., Fifth Floor
  21  *      Boston, MA 02110, USA.
  22  */
  23
  24 #include <dlg_internals.h>
  25
  26 static void
  27 reapchild(int sig)
  28 {
  29     (void) sig;
  30 }
  31
  32 /*
  33  * Open a pipe which ties stderr and stdout together.
  34  */
  35 FILE *
  36 dlg_popen(const char *command, const char *type)
  37 {
  38     FILE *result = 0;
  39     int fd[2];
  40
  41     if ((*type == 'r' || *type == 'w') && pipe(fd) == 0) {
  42         char *blob;
  43
  44         switch (fork()) {
  45         case -1:                /* Error. */
  46             (void) close(fd[0]);
  47             (void) close(fd[1]);
  48             break;
  49         case 0:         /* child. */
  50             if (*type == 'r') {
  51                 if (fd[1] != STDOUT_FILENO) {
  52                     (void) dup2(fd[1], STDOUT_FILENO);
  53                     (void) close(fd[1]);
  54                 }
  55                 (void) dup2(STDOUT_FILENO, STDERR_FILENO);
  56                 (void) close(fd[0]);
  57             } else {
  58                 if (fd[0] != STDIN_FILENO) {
  59                     (void) dup2(fd[0], STDIN_FILENO);
  60                     (void) close(fd[0]);
  61                 }
  62                 (void) close(fd[1]);
  63                 (void) close(STDERR_FILENO);
  64             }
  65             /*
  66              * Bourne shell needs "-c" option to force it to use only the
  67              * given command.  Also, it needs the command to be parsed into
  68              * tokens.
  69              */
  70             if ((blob = malloc(10 + strlen(command))) != 0) {
  71                 char **argv;
  72                 sprintf(blob, "sh -c \"%s\"", command);
  73                 argv = dlg_string_to_argv(blob);
  74                 execvp("sh", argv);
  75             }
  76             _exit(127);
  77             /* NOTREACHED */
  78         default:                /* parent */
  79             if (*type == 'r') {
  80                 result = fdopen(fd[0], type);
  81                 (void) close(fd[1]);
  82             } else {
  83                 result = fdopen(fd[1], type);
  84                 (void) close(fd[0]);
  85             }
  86             break;
  87         }
  88     }
  89
  90     return result;
  91 }
  92
  93 /*
  94  * Display text from a pipe in a scrolling window.
  95  */
  96 int
  97 dialog_prgbox(const char *title,
  98               const char *cprompt,
  99               const char *command,
 100               int height,
 101               int width,
 102               int pauseopt)
 103 {
 104     int code;
 105     FILE *fp;
 106     void (*oldreaper) (int) = signal(SIGCHLD, reapchild);
 107
 108     fp = dlg_popen(command, "r");
 109     if (fp == NULL)
 110         dlg_exiterr("pipe open failed: %s", command);
 111
 112     code = dlg_progressbox(title, cprompt, height, width, pauseopt, fp);
 113
 114     pclose(fp);
 115     signal(SIGCHLD, oldreaper);
 116
 117     return code;
 118 }