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[glibc.git] / libio / iopopen.c
blob62a6de20f5ec62cb10abdceda2f3a0e56f87daf3
1 /* Copyright (C) 1993, 1997, 1998 Free Software Foundation, Inc.
2 This file is part of the GNU IO Library.
3 Written by Per Bothner <bothner@cygnus.com>.
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU General Public License as
7 published by the Free Software Foundation; either version 2, or (at
8 your option) any later version.
10 This library is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this library; see the file COPYING. If not, write to
17 the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
18 MA 02111-1307, USA.
20 As a special exception, if you link this library with files
21 compiled with a GNU compiler to produce an executable, this does
22 not cause the resulting executable to be covered by the GNU General
23 Public License. This exception does not however invalidate any
24 other reasons why the executable file might be covered by the GNU
25 General Public License. */
27 #ifndef _POSIX_SOURCE
28 # define _POSIX_SOURCE
29 #endif
30 #include "libioP.h"
31 #if _IO_HAVE_SYS_WAIT
32 #include <signal.h>
33 #include <unistd.h>
34 #ifdef __STDC__
35 #include <stdlib.h>
36 #endif
37 #ifdef _LIBC
38 # include <unistd.h>
39 #endif
40 #include <sys/types.h>
41 #include <sys/wait.h>
43 #ifndef _IO_fork
44 #ifdef _LIBC
45 #define _IO_fork __vfork
46 #else
47 #define _IO_fork vfork /* defined in libiberty, if needed */
48 #endif
49 extern _IO_pid_t _IO_fork __P ((void));
50 #endif
52 #endif /* _IO_HAVE_SYS_WAIT */
54 #ifndef _IO_pipe
55 #ifdef _LIBC
56 #define _IO_pipe __pipe
57 #else
58 #define _IO_pipe pipe
59 #endif
60 extern int _IO_pipe __P ((int des[2]));
61 #endif
63 #ifndef _IO_dup2
64 #ifdef _LIBC
65 #define _IO_dup2 __dup2
66 #else
67 #define _IO_dup2 dup2
68 #endif
69 extern int _IO_dup2 __P ((int fd, int fd2));
70 #endif
72 #ifndef _IO_waitpid
73 #ifdef _LIBC
74 #define _IO_waitpid __waitpid
75 #else
76 #define _IO_waitpid waitpid
77 #endif
78 #endif
80 #ifndef _IO_execl
81 #define _IO_execl execl
82 #endif
83 #ifndef _IO__exit
84 #define _IO__exit _exit
85 #endif
87 #ifndef _IO_close
88 #ifdef _LIBC
89 #define _IO_close __close
90 #else
91 #define _IO_close close
92 #endif
93 #endif
95 struct _IO_proc_file
97 struct _IO_FILE_plus file;
98 /* Following fields must match those in class procbuf (procbuf.h) */
99 _IO_pid_t pid;
100 struct _IO_proc_file *next;
102 typedef struct _IO_proc_file _IO_proc_file;
104 static struct _IO_proc_file *proc_file_chain = NULL;
106 _IO_FILE *
107 _IO_proc_open (fp, command, mode)
108 _IO_FILE *fp;
109 const char *command;
110 const char *mode;
112 #if _IO_HAVE_SYS_WAIT
113 volatile int read_or_write;
114 volatile int parent_end, child_end;
115 int pipe_fds[2];
116 _IO_pid_t child_pid;
117 if (_IO_file_is_open (fp))
118 return NULL;
119 if (_IO_pipe (pipe_fds) < 0)
120 return NULL;
121 if (mode[0] == 'r' && mode[1] == '\0')
123 parent_end = pipe_fds[0];
124 child_end = pipe_fds[1];
125 read_or_write = _IO_NO_WRITES;
127 else if (mode[0] == 'w' && mode[1] == '\0')
129 parent_end = pipe_fds[1];
130 child_end = pipe_fds[0];
131 read_or_write = _IO_NO_READS;
133 else
135 __set_errno (EINVAL);
136 return NULL;
138 ((_IO_proc_file *) fp)->pid = child_pid = _IO_fork ();
139 if (child_pid == 0)
141 int child_std_end = mode[0] == 'r' ? 1 : 0;
142 _IO_close (parent_end);
143 if (child_end != child_std_end)
145 _IO_dup2 (child_end, child_std_end);
146 _IO_close (child_end);
148 /* POSIX.2: "popen() shall ensure that any streams from previous
149 popen() calls that remain open in the parent process are closed
150 in the new child process." */
151 while (proc_file_chain)
153 _IO_close (_IO_fileno ((_IO_FILE *) proc_file_chain));
154 proc_file_chain = proc_file_chain->next;
157 _IO_execl ("/bin/sh", "sh", "-c", command, (char *) 0);
158 _IO__exit (127);
160 _IO_close (child_end);
161 if (child_pid < 0)
163 _IO_close (parent_end);
164 return NULL;
166 _IO_fileno (fp) = parent_end;
168 /* Link into proc_file_chain. */
169 ((_IO_proc_file *) fp)->next = proc_file_chain;
170 proc_file_chain = (_IO_proc_file *) fp;
172 _IO_mask_flags (fp, read_or_write, _IO_NO_READS|_IO_NO_WRITES);
173 return fp;
174 #else /* !_IO_HAVE_SYS_WAIT */
175 return NULL;
176 #endif
179 _IO_FILE *
180 _IO_popen (command, mode)
181 const char *command;
182 const char *mode;
184 struct locked_FILE
186 struct _IO_proc_file fpx;
187 #ifdef _IO_MTSAFE_IO
188 _IO_lock_t lock;
189 #endif
190 } *new_f;
191 _IO_FILE *fp;
193 new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
194 if (new_f == NULL)
195 return NULL;
196 #ifdef _IO_MTSAFE_IO
197 new_f->fpx.file.file._lock = &new_f->lock;
198 #endif
199 fp = &new_f->fpx.file.file;
200 _IO_init (fp, 0);
201 _IO_JUMPS (fp) = &_IO_proc_jumps;
202 _IO_file_init (fp);
203 #if !_IO_UNIFIED_JUMPTABLES
204 new_f->fpx.file.vtable = NULL;
205 #endif
206 if (_IO_proc_open (fp, command, mode) != NULL)
207 return fp;
208 _IO_un_link (fp);
209 free (new_f);
210 return NULL;
213 #ifdef strong_alias
214 strong_alias (_IO_popen, popen);
215 #endif
218 _IO_proc_close (fp)
219 _IO_FILE *fp;
221 /* This is not name-space clean. FIXME! */
222 #if _IO_HAVE_SYS_WAIT
223 int wstatus;
224 _IO_proc_file **ptr = &proc_file_chain;
225 _IO_pid_t wait_pid;
226 int status = -1;
228 /* Unlink from proc_file_chain. */
229 for ( ; *ptr != NULL; ptr = &(*ptr)->next)
231 if (*ptr == (_IO_proc_file *) fp)
233 *ptr = (*ptr)->next;
234 status = 0;
235 break;
239 if (status < 0 || _IO_close (_IO_fileno(fp)) < 0)
240 return -1;
241 /* POSIX.2 Rationale: "Some historical implementations either block
242 or ignore the signals SIGINT, SIGQUIT, and SIGHUP while waiting
243 for the child process to terminate. Since this behavior is not
244 described in POSIX.2, such implementations are not conforming." */
247 wait_pid = _IO_waitpid (((_IO_proc_file *) fp)->pid, &wstatus, 0);
249 while (wait_pid == -1 && errno == EINTR);
250 if (wait_pid == -1)
251 return -1;
252 return wstatus;
253 #else /* !_IO_HAVE_SYS_WAIT */
254 return -1;
255 #endif
258 struct _IO_jump_t _IO_proc_jumps = {
259 JUMP_INIT_DUMMY,
260 JUMP_INIT(finish, _IO_file_finish),
261 JUMP_INIT(overflow, _IO_file_overflow),
262 JUMP_INIT(underflow, _IO_file_underflow),
263 JUMP_INIT(uflow, _IO_default_uflow),
264 JUMP_INIT(pbackfail, _IO_default_pbackfail),
265 JUMP_INIT(xsputn, _IO_file_xsputn),
266 JUMP_INIT(xsgetn, _IO_default_xsgetn),
267 JUMP_INIT(seekoff, _IO_file_seekoff),
268 JUMP_INIT(seekpos, _IO_default_seekpos),
269 JUMP_INIT(setbuf, _IO_file_setbuf),
270 JUMP_INIT(sync, _IO_file_sync),
271 JUMP_INIT(doallocate, _IO_file_doallocate),
272 JUMP_INIT(read, _IO_file_read),
273 JUMP_INIT(write, _IO_file_write),
274 JUMP_INIT(seek, _IO_file_seek),
275 JUMP_INIT(close, _IO_proc_close),
276 JUMP_INIT(stat, _IO_file_stat),
277 JUMP_INIT(showmanyc, _IO_default_showmanyc),
278 JUMP_INIT(imbue, _IO_default_imbue)