xref: /freebsd/contrib/dialog/prgbox.c (revision a466cc55373fc3cf86837f09da729535b57e69a1)
1 /*
2  *  $Id: prgbox.c,v 1.14 2019/07/25 00:07:15 tom Exp $
3  *
4  *  prgbox.c -- implements the prg box
5  *
6  *  Copyright 2011-2016,2019	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 <dialog.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 }
119