libio/iopopen.c

   1 /* Copyright (C) 1993, 1997-2002, 2003, 2004 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 # include <not-cancel.h>
  43 #endif
  44 #include <sys/types.h>
  45 #include <sys/wait.h>
  46
  47 #ifndef _IO_fork
  48 #ifdef _LIBC
  49 #define _IO_fork __fork
  50 #else
  51 #define _IO_fork fork /* defined in libiberty, if needed */
  52 #endif
  53 extern _IO_pid_t _IO_fork (void) __THROW;
  54 #endif
  55
  56 #endif /* _IO_HAVE_SYS_WAIT */
  57
  58 #ifndef _IO_pipe
  59 #ifdef _LIBC
  60 #define _IO_pipe __pipe
  61 #else
  62 #define _IO_pipe pipe
  63 #endif
  64 extern int _IO_pipe (int des[2]) __THROW;
  65 #endif
  66
  67 #ifndef _IO_dup2
  68 #ifdef _LIBC
  69 #define _IO_dup2 __dup2
  70 #else
  71 #define _IO_dup2 dup2
  72 #endif
  73 extern int _IO_dup2 (int fd, int fd2) __THROW;
  74 #endif
  75
  76 #ifndef _IO_waitpid
  77 #ifdef _LIBC
  78 #define _IO_waitpid waitpid_not_cancel
  79 #else
  80 #define _IO_waitpid waitpid
  81 #endif
  82 #endif
  83
  84 #ifndef _IO_execl
  85 #define _IO_execl execl
  86 #endif
  87 #ifndef _IO__exit
  88 #define _IO__exit _exit
  89 #endif
  90
  91 #ifndef _IO_close
  92 #ifdef _LIBC
  93 #define _IO_close close_not_cancel
  94 #else
  95 #define _IO_close close
  96 #endif
  97 #endif
  98
  99 struct _IO_proc_file
 100 {
 101   struct _IO_FILE_plus file;
 102   /* Following fields must match those in class procbuf (procbuf.h) */
 103   _IO_pid_t pid;
 104   struct _IO_proc_file *next;
 105 };
 106 typedef struct _IO_proc_file _IO_proc_file;
 107
 108 static const struct _IO_jump_t _IO_proc_jumps;
 109
 110 static struct _IO_proc_file *proc_file_chain;
 111
 112 #ifdef _IO_MTSAFE_IO
 113 static _IO_lock_t proc_file_chain_lock = _IO_lock_initializer;
 114
 115 static void
 116 unlock (void *not_used)
 117 {
 118   _IO_lock_unlock (proc_file_chain_lock);
 119 }
 120 #endif
 121
 122 _IO_FILE *
 123 _IO_new_proc_open (fp, command, mode)
 124      _IO_FILE *fp;
 125      const char *command;
 126      const char *mode;
 127 {
 128 #if _IO_HAVE_SYS_WAIT
 129   volatile int read_or_write;
 130   volatile int parent_end, child_end;
 131   int pipe_fds[2];
 132   _IO_pid_t child_pid;
 133   if (_IO_file_is_open (fp))
 134     return NULL;
 135   if (_IO_pipe (pipe_fds) < 0)
 136     return NULL;
 137   if (mode[0] == 'r' && mode[1] == '\0')
 138     {
 139       parent_end = pipe_fds[0];
 140       child_end = pipe_fds[1];
 141       read_or_write = _IO_NO_WRITES;
 142     }
 143   else if (mode[0] == 'w' && mode[1] == '\0')
 144     {
 145       parent_end = pipe_fds[1];
 146       child_end = pipe_fds[0];
 147       read_or_write = _IO_NO_READS;
 148     }
 149   else
 150     {
 151       _IO_close (pipe_fds[0]);
 152       _IO_close (pipe_fds[1]);
 153       __set_errno (EINVAL);
 154       return NULL;
 155     }
 156   ((_IO_proc_file *) fp)->pid = child_pid = _IO_fork ();
 157   if (child_pid == 0)
 158     {
 159       int child_std_end = mode[0] == 'r' ? 1 : 0;
 160       struct _IO_proc_file *p;
 161
 162       _IO_close (parent_end);
 163       if (child_end != child_std_end)
 164         {
 165           _IO_dup2 (child_end, child_std_end);
 166           _IO_close (child_end);
 167         }
 168       /* POSIX.2:  "popen() shall ensure that any streams from previous
 169          popen() calls that remain open in the parent process are closed
 170          in the new child process." */
 171       for (p = proc_file_chain; p; p = p->next)
 172         _IO_close (_IO_fileno ((_IO_FILE *) p));
 173
 174       _IO_execl ("/bin/sh", "sh", "-c", command, (char *) 0);
 175       _IO__exit (127);
 176     }
 177   _IO_close (child_end);
 178   if (child_pid < 0)
 179     {
 180       _IO_close (parent_end);
 181       return NULL;
 182     }
 183   _IO_fileno (fp) = parent_end;
 184
 185   /* Link into proc_file_chain. */
 186 #ifdef _IO_MTSAFE_IO
 187   _IO_cleanup_region_start_noarg (unlock);
 188   _IO_lock_lock (proc_file_chain_lock);
 189 #endif
 190   ((_IO_proc_file *) fp)->next = proc_file_chain;
 191   proc_file_chain = (_IO_proc_file *) fp;
 192 #ifdef _IO_MTSAFE_IO
 193   _IO_lock_unlock (proc_file_chain_lock);
 194   _IO_cleanup_region_end (0);
 195 #endif
 196
 197   _IO_mask_flags (fp, read_or_write, _IO_NO_READS|_IO_NO_WRITES);
 198   return fp;
 199 #else /* !_IO_HAVE_SYS_WAIT */
 200   return NULL;
 201 #endif
 202 }
 203
 204 _IO_FILE *
 205 _IO_new_popen (command, mode)
 206      const char *command;
 207      const char *mode;
 208 {
 209   struct locked_FILE
 210   {
 211     struct _IO_proc_file fpx;
 212 #ifdef _IO_MTSAFE_IO
 213     _IO_lock_t lock;
 214 #endif
 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   INTUSE(_IO_init) (fp, 0);
 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 static const 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 strong_alias (_IO_new_popen, __new_popen)
 311 versioned_symbol (libc, _IO_new_popen, _IO_popen, GLIBC_2_1);
 312 versioned_symbol (libc, __new_popen, popen, GLIBC_2_1);
 313 versioned_symbol (libc, _IO_new_proc_open, _IO_proc_open, GLIBC_2_1);
 314 versioned_symbol (libc, _IO_new_proc_close, _IO_proc_close, GLIBC_2_1);