libio/iopopen.c

   1 /* Copyright (C) 1993,1997-2001,2002 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Written by Per Bothner <bothner@cygnus.com>.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.
  19
  20    As a special exception, if you link the code in this file with
  21    files compiled with a GNU compiler to produce an executable,
  22    that does not cause the resulting executable to be covered by
  23    the GNU Lesser General Public License.  This exception does not
  24    however invalidate any other reasons why the executable file
  25    might be covered by the GNU Lesser General Public License.
  26    This exception applies to code released by its copyright holders
  27    in files containing the exception.  */
  28
  29 #ifndef _POSIX_SOURCE
  30 # define _POSIX_SOURCE
  31 #endif
  32 #include "libioP.h"
  33 #if _IO_HAVE_SYS_WAIT
  34 #include <signal.h>
  35 #include <unistd.h>
  36 #ifdef __STDC__
  37 #include <stdlib.h>
  38 #endif
  39 #ifdef _LIBC
  40 # include <unistd.h>
  41 # include <shlib-compat.h>
  42 #endif
  43 #include <sys/types.h>
  44 #include <sys/wait.h>
  45
  46 #ifndef _IO_fork
  47 #ifdef _LIBC
  48 #define _IO_fork __vfork
  49 #else
  50 #define _IO_fork vfork /* defined in libiberty, if needed */
  51 #endif
  52 extern _IO_pid_t _IO_fork __P ((void));
  53 #endif
  54
  55 #endif /* _IO_HAVE_SYS_WAIT */
  56
  57 #ifndef _IO_pipe
  58 #ifdef _LIBC
  59 #define _IO_pipe __pipe
  60 #else
  61 #define _IO_pipe pipe
  62 #endif
  63 extern int _IO_pipe __P ((int des[2]));
  64 #endif
  65
  66 #ifndef _IO_dup2
  67 #ifdef _LIBC
  68 #define _IO_dup2 __dup2
  69 #else
  70 #define _IO_dup2 dup2
  71 #endif
  72 extern int _IO_dup2 __P ((int fd, int fd2));
  73 #endif
  74
  75 #ifndef _IO_waitpid
  76 #ifdef _LIBC
  77 #define _IO_waitpid __waitpid
  78 #else
  79 #define _IO_waitpid waitpid
  80 #endif
  81 #endif
  82
  83 #ifndef _IO_execl
  84 #define _IO_execl execl
  85 #endif
  86 #ifndef _IO__exit
  87 #define _IO__exit _exit
  88 #endif
  89
  90 #ifndef _IO_close
  91 #ifdef _LIBC
  92 #define _IO_close __close
  93 #else
  94 #define _IO_close close
  95 #endif
  96 #endif
  97
  98 struct _IO_proc_file
  99 {
 100   struct _IO_FILE_plus file;
 101   /* Following fields must match those in class procbuf (procbuf.h) */
 102   _IO_pid_t pid;
 103   struct _IO_proc_file *next;
 104 };
 105 typedef struct _IO_proc_file _IO_proc_file;
 106
 107 static struct _IO_jump_t _IO_wproc_jumps;
 108
 109 static struct _IO_proc_file *proc_file_chain;
 110
 111 #ifdef _IO_MTSAFE_IO
 112 static _IO_lock_t proc_file_chain_lock = _IO_lock_initializer;
 113
 114 static void
 115 unlock (void *not_used)
 116 {
 117   _IO_lock_unlock (proc_file_chain_lock);
 118 }
 119 #endif
 120
 121 _IO_FILE *
 122 _IO_new_proc_open (fp, command, mode)
 123      _IO_FILE *fp;
 124      const char *command;
 125      const char *mode;
 126 {
 127 #if _IO_HAVE_SYS_WAIT
 128   volatile int read_or_write;
 129   volatile int parent_end, child_end;
 130   int pipe_fds[2];
 131   _IO_pid_t child_pid;
 132   if (_IO_file_is_open (fp))
 133     return NULL;
 134   if (_IO_pipe (pipe_fds) < 0)
 135     return NULL;
 136   if (mode[0] == 'r' && mode[1] == '\0')
 137     {
 138       parent_end = pipe_fds[0];
 139       child_end = pipe_fds[1];
 140       read_or_write = _IO_NO_WRITES;
 141     }
 142   else if (mode[0] == 'w' && mode[1] == '\0')
 143     {
 144       parent_end = pipe_fds[1];
 145       child_end = pipe_fds[0];
 146       read_or_write = _IO_NO_READS;
 147     }
 148   else
 149     {
 150       _IO_close (pipe_fds[0]);
 151       _IO_close (pipe_fds[1]);
 152       __set_errno (EINVAL);
 153       return NULL;
 154     }
 155   ((_IO_proc_file *) fp)->pid = child_pid = _IO_fork ();
 156   if (child_pid == 0)
 157     {
 158       int child_std_end = mode[0] == 'r' ? 1 : 0;
 159       struct _IO_proc_file *p;
 160
 161       _IO_close (parent_end);
 162       if (child_end != child_std_end)
 163         {
 164           _IO_dup2 (child_end, child_std_end);
 165           _IO_close (child_end);
 166         }
 167       /* POSIX.2:  "popen() shall ensure that any streams from previous
 168          popen() calls that remain open in the parent process are closed
 169          in the new child process." */
 170       for (p = proc_file_chain; p; p = p->next)
 171         _IO_close (_IO_fileno ((_IO_FILE *) p));
 172
 173       _IO_execl ("/bin/sh", "sh", "-c", command, (char *) 0);
 174       _IO__exit (127);
 175     }
 176   _IO_close (child_end);
 177   if (child_pid < 0)
 178     {
 179       _IO_close (parent_end);
 180       return NULL;
 181     }
 182   _IO_fileno (fp) = parent_end;
 183
 184   /* Link into proc_file_chain. */
 185 #ifdef _IO_MTSAFE_IO
 186   _IO_cleanup_region_start_noarg (unlock);
 187   _IO_lock_lock (proc_file_chain_lock);
 188 #endif
 189   ((_IO_proc_file *) fp)->next = proc_file_chain;
 190   proc_file_chain = (_IO_proc_file *) fp;
 191 #ifdef _IO_MTSAFE_IO
 192   _IO_lock_unlock (proc_file_chain_lock);
 193   _IO_cleanup_region_end (0);
 194 #endif
 195
 196   _IO_mask_flags (fp, read_or_write, _IO_NO_READS|_IO_NO_WRITES);
 197   return fp;
 198 #else /* !_IO_HAVE_SYS_WAIT */
 199   return NULL;
 200 #endif
 201 }
 202
 203 _IO_FILE *
 204 _IO_new_popen (command, mode)
 205      const char *command;
 206      const char *mode;
 207 {
 208   struct locked_FILE
 209   {
 210     struct _IO_proc_file fpx;
 211 #ifdef _IO_MTSAFE_IO
 212     _IO_lock_t lock;
 213 #endif
 214     struct _IO_wide_data wd;
 215   } *new_f;
 216   _IO_FILE *fp;
 217
 218   new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
 219   if (new_f == NULL)
 220     return NULL;
 221 #ifdef _IO_MTSAFE_IO
 222   new_f->fpx.file.file._lock = &new_f->lock;
 223 #endif
 224   fp = &new_f->fpx.file.file;
 225   _IO_no_init (fp, 0, 0, &new_f->wd, &_IO_wproc_jumps);
 226   _IO_JUMPS (&new_f->fpx.file) = &_IO_proc_jumps;
 227   _IO_new_file_init (&new_f->fpx.file);
 228 #if  !_IO_UNIFIED_JUMPTABLES
 229   new_f->fpx.file.vtable = NULL;
 230 #endif
 231   if (_IO_new_proc_open (fp, command, mode) != NULL)
 232     return (_IO_FILE *) &new_f->fpx.file;
 233   INTUSE(_IO_un_link) (&new_f->fpx.file);
 234   free (new_f);
 235   return NULL;
 236 }
 237
 238 int
 239 _IO_new_proc_close (fp)
 240      _IO_FILE *fp;
 241 {
 242   /* This is not name-space clean. FIXME! */
 243 #if _IO_HAVE_SYS_WAIT
 244   int wstatus;
 245   _IO_proc_file **ptr = &proc_file_chain;
 246   _IO_pid_t wait_pid;
 247   int status = -1;
 248
 249   /* Unlink from proc_file_chain. */
 250 #ifdef _IO_MTSAFE_IO
 251   _IO_cleanup_region_start_noarg (unlock);
 252   _IO_lock_lock (proc_file_chain_lock);
 253 #endif
 254   for ( ; *ptr != NULL; ptr = &(*ptr)->next)
 255     {
 256       if (*ptr == (_IO_proc_file *) fp)
 257         {
 258           *ptr = (*ptr)->next;
 259           status = 0;
 260           break;
 261         }
 262     }
 263 #ifdef _IO_MTSAFE_IO
 264   _IO_lock_unlock (proc_file_chain_lock);
 265   _IO_cleanup_region_end (0);
 266 #endif
 267
 268   if (status < 0 || _IO_close (_IO_fileno(fp)) < 0)
 269     return -1;
 270   /* POSIX.2 Rationale:  "Some historical implementations either block
 271      or ignore the signals SIGINT, SIGQUIT, and SIGHUP while waiting
 272      for the child process to terminate.  Since this behavior is not
 273      described in POSIX.2, such implementations are not conforming." */
 274   do
 275     {
 276       wait_pid = _IO_waitpid (((_IO_proc_file *) fp)->pid, &wstatus, 0);
 277     }
 278   while (wait_pid == -1 && errno == EINTR);
 279   if (wait_pid == -1)
 280     return -1;
 281   return wstatus;
 282 #else /* !_IO_HAVE_SYS_WAIT */
 283   return -1;
 284 #endif
 285 }
 286
 287 struct _IO_jump_t _IO_proc_jumps = {
 288   JUMP_INIT_DUMMY,
 289   JUMP_INIT(finish, _IO_new_file_finish),
 290   JUMP_INIT(overflow, _IO_new_file_overflow),
 291   JUMP_INIT(underflow, _IO_new_file_underflow),
 292   JUMP_INIT(uflow, INTUSE(_IO_default_uflow)),
 293   JUMP_INIT(pbackfail, INTUSE(_IO_default_pbackfail)),
 294   JUMP_INIT(xsputn, _IO_new_file_xsputn),
 295   JUMP_INIT(xsgetn, INTUSE(_IO_default_xsgetn)),
 296   JUMP_INIT(seekoff, _IO_new_file_seekoff),
 297   JUMP_INIT(seekpos, _IO_default_seekpos),
 298   JUMP_INIT(setbuf, _IO_new_file_setbuf),
 299   JUMP_INIT(sync, _IO_new_file_sync),
 300   JUMP_INIT(doallocate, INTUSE(_IO_file_doallocate)),
 301   JUMP_INIT(read, INTUSE(_IO_file_read)),
 302   JUMP_INIT(write, _IO_new_file_write),
 303   JUMP_INIT(seek, INTUSE(_IO_file_seek)),
 304   JUMP_INIT(close, _IO_new_proc_close),
 305   JUMP_INIT(stat, INTUSE(_IO_file_stat)),
 306   JUMP_INIT(showmanyc, _IO_default_showmanyc),
 307   JUMP_INIT(imbue, _IO_default_imbue)
 308 };
 309
 310 static struct _IO_jump_t _IO_wproc_jumps = {
 311   JUMP_INIT_DUMMY,
 312   JUMP_INIT(finish, _IO_new_file_finish),
 313   JUMP_INIT(overflow, _IO_new_file_overflow),
 314   JUMP_INIT(underflow, _IO_new_file_underflow),
 315   JUMP_INIT(uflow, INTUSE(_IO_default_uflow)),
 316   JUMP_INIT(pbackfail, INTUSE(_IO_default_pbackfail)),
 317   JUMP_INIT(xsputn, _IO_new_file_xsputn),
 318   JUMP_INIT(xsgetn, INTUSE(_IO_default_xsgetn)),
 319   JUMP_INIT(seekoff, _IO_new_file_seekoff),
 320   JUMP_INIT(seekpos, _IO_default_seekpos),
 321   JUMP_INIT(setbuf, _IO_new_file_setbuf),
 322   JUMP_INIT(sync, _IO_new_file_sync),
 323   JUMP_INIT(doallocate, INTUSE(_IO_file_doallocate)),
 324   JUMP_INIT(read, INTUSE(_IO_file_read)),
 325   JUMP_INIT(write, _IO_new_file_write),
 326   JUMP_INIT(seek, INTUSE(_IO_file_seek)),
 327   JUMP_INIT(close, _IO_new_proc_close),
 328   JUMP_INIT(stat, INTUSE(_IO_file_stat)),
 329   JUMP_INIT(showmanyc, _IO_default_showmanyc),
 330   JUMP_INIT(imbue, _IO_default_imbue)
 331 };
 332
 333 strong_alias (_IO_new_popen, __new_popen)
 334 versioned_symbol (libc, _IO_new_popen, _IO_popen, GLIBC_2_1);
 335 versioned_symbol (libc, __new_popen, popen, GLIBC_2_1);
 336 versioned_symbol (libc, _IO_new_proc_open, _IO_proc_open, GLIBC_2_1);
 337 versioned_symbol (libc, _IO_new_proc_close, _IO_proc_close, GLIBC_2_1);