summary refs log tree commit diff
path: root/libio/iopopen.c
blob: 59d4fc3f0ed2f3603712cbc2c0ac7dfd44c8805f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
/* Copyright (C) 1993, 1997 Free Software Foundation, Inc.
   This file is part of the GNU IO Library.
   Written by Per Bothner <bothner@cygnus.com>.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This library is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this library; see the file COPYING.  If not, write to
   the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
   MA 02111-1307, USA.

   As a special exception, if you link this library with files
   compiled with a GNU compiler to produce an executable, this does
   not cause the resulting executable to be covered by the GNU General
   Public License.  This exception does not however invalidate any
   other reasons why the executable file might be covered by the GNU
   General Public License.  */

#ifndef _POSIX_SOURCE
# define _POSIX_SOURCE
#endif
#include "libioP.h"
#if _IO_HAVE_SYS_WAIT
#include <signal.h>
#include <unistd.h>
#ifdef __STDC__
#include <stdlib.h>
#endif
#ifdef _LIBC
# include <unistd.h>
#endif
#include <sys/types.h>
#include <sys/wait.h>

#ifndef _IO_fork
#define _IO_fork vfork /* defined in libiberty, if needed */
extern _IO_pid_t _IO_fork __P ((void));
#endif

#endif /* _IO_HAVE_SYS_WAIT */

#ifndef _IO_pipe
#define _IO_pipe pipe
extern int _IO_pipe __P ((int des[2]));
#endif

#ifndef _IO_dup2
#define _IO_dup2 dup2
extern int _IO_dup2 __P ((int fd, int fd2));
#endif

#ifndef _IO_waitpid
#define _IO_waitpid waitpid
#endif

#ifndef _IO_execl
#define _IO_execl execl
#endif
#ifndef _IO__exit
#define _IO__exit _exit
#endif

#ifndef _IO_close
#define _IO_close close
#endif

struct _IO_proc_file
{
  struct _IO_FILE_plus file;
  /* Following fields must match those in class procbuf (procbuf.h) */
  _IO_pid_t pid;
  struct _IO_proc_file *next;
};
typedef struct _IO_proc_file _IO_proc_file;

static struct _IO_proc_file *proc_file_chain = NULL;

_IO_FILE *
_IO_proc_open (fp, command, mode)
     _IO_FILE *fp;
     const char *command;
     const char *mode;
{
#if _IO_HAVE_SYS_WAIT
  volatile int read_or_write;
  volatile int parent_end, child_end;
  int pipe_fds[2];
  _IO_pid_t child_pid;
  if (_IO_file_is_open (fp))
    return NULL;
  if (_IO_pipe (pipe_fds) < 0)
    return NULL;
  if (mode[0] == 'r')
    {
      parent_end = pipe_fds[0];
      child_end = pipe_fds[1];
      read_or_write = _IO_NO_WRITES;
    }
  else
    {
      parent_end = pipe_fds[1];
      child_end = pipe_fds[0];
      read_or_write = _IO_NO_READS;
    }
  ((_IO_proc_file *) fp)->pid = child_pid = _IO_fork ();
  if (child_pid == 0)
    {
      int child_std_end = mode[0] == 'r' ? 1 : 0;
      _IO_close (parent_end);
      if (child_end != child_std_end)
	{
	  _IO_dup2 (child_end, child_std_end);
	  _IO_close (child_end);
	}
      /* POSIX.2:  "popen() shall ensure that any streams from previous
         popen() calls that remain open in the parent process are closed
	 in the new child process." */
      while (proc_file_chain)
	{
	  _IO_close (_IO_fileno ((_IO_FILE *) proc_file_chain));
	  proc_file_chain = proc_file_chain->next;
	}

      _IO_execl ("/bin/sh", "sh", "-c", command, (char *) 0);
      _IO__exit (127);
    }
  _IO_close (child_end);
  if (child_pid < 0)
    {
      _IO_close (parent_end);
      return NULL;
    }
  _IO_fileno (fp) = parent_end;

  /* Link into proc_file_chain. */
  ((_IO_proc_file *) fp)->next = proc_file_chain;
  proc_file_chain = (_IO_proc_file *) fp;

  _IO_mask_flags (fp, read_or_write, _IO_NO_READS|_IO_NO_WRITES);
  return fp;
#else /* !_IO_HAVE_SYS_WAIT */
  return NULL;
#endif
}

_IO_FILE *
_IO_popen (command, mode)
     const char *command;
     const char *mode;
{
  struct locked_FILE
  {
    struct _IO_proc_file fpx;
#ifdef _IO_MTSAFE_IO
    _IO_lock_t lock;
#endif
  } *new_f;
  _IO_FILE *fp;

  new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
  if (new_f == NULL)
    return NULL;
#ifdef _IO_MTSAFE_IO
  new_f->fpx.file.file._lock = &new_f->lock;
#endif
  fp = (_IO_FILE*)&new_f->fpx;
  _IO_init (fp, 0);
  _IO_JUMPS (fp) = &_IO_proc_jumps;
  _IO_file_init (fp);
#if  !_IO_UNIFIED_JUMPTABLES
  ((struct _IO_FILE_plus *) fp)->vtable = NULL;
#endif
  if (_IO_proc_open (fp, command, mode) != NULL)
    return fp;
  free (new_f);
  return NULL;
}

#ifdef strong_alias
strong_alias (_IO_popen, popen);
#endif

int
_IO_proc_close (fp)
     _IO_FILE *fp;
{
  /* This is not name-space clean. FIXME! */
#if _IO_HAVE_SYS_WAIT
  int wstatus;
  _IO_proc_file **ptr = &proc_file_chain;
  _IO_pid_t wait_pid;
  int status = -1;

  /* Unlink from proc_file_chain. */
  for ( ; *ptr != NULL; ptr = &(*ptr)->next)
    {
      if (*ptr == (_IO_proc_file *) fp)
	{
	  *ptr = (*ptr)->next;
	  status = 0;
	  break;
	}
    }

  if (status < 0 || _IO_close (_IO_fileno(fp)) < 0)
    return -1;
  /* POSIX.2 Rationale:  "Some historical implementations either block
     or ignore the signals SIGINT, SIGQUIT, and SIGHUP while waiting
     for the child process to terminate.  Since this behavior is not
     described in POSIX.2, such implementations are not conforming." */
  do
    {
      wait_pid = _IO_waitpid (((_IO_proc_file *) fp)->pid, &wstatus, 0);
    }
  while (wait_pid == -1 && errno == EINTR);
  if (wait_pid == -1)
    return -1;
  return wstatus;
#else /* !_IO_HAVE_SYS_WAIT */
  return -1;
#endif
}

struct _IO_jump_t _IO_proc_jumps = {
  JUMP_INIT_DUMMY,
  JUMP_INIT(finish, _IO_file_finish),
  JUMP_INIT(overflow, _IO_file_overflow),
  JUMP_INIT(underflow, _IO_file_underflow),
  JUMP_INIT(uflow, _IO_default_uflow),
  JUMP_INIT(pbackfail, _IO_default_pbackfail),
  JUMP_INIT(xsputn, _IO_file_xsputn),
  JUMP_INIT(xsgetn, _IO_default_xsgetn),
  JUMP_INIT(seekoff, _IO_file_seekoff),
  JUMP_INIT(seekpos, _IO_default_seekpos),
  JUMP_INIT(setbuf, _IO_file_setbuf),
  JUMP_INIT(sync, _IO_file_sync),
  JUMP_INIT(doallocate, _IO_file_doallocate),
  JUMP_INIT(read, _IO_file_read),
  JUMP_INIT(write, _IO_file_write),
  JUMP_INIT(seek, _IO_file_seek),
  JUMP_INIT(close, _IO_proc_close),
  JUMP_INIT(stat, _IO_file_stat)
};