libio/iopopen.c

   1 /* Copyright (C) 1993, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU IO Library.
   3    Written by Per Bothner <bothner@cygnus.com>.
   4
   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.
   9
  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.
  14
  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.
  19
  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.  */
  26
  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 # include <shlib-compat.h>
  40 #endif
  41 #include <sys/types.h>
  42 #include <sys/wait.h>
  43
  44 #ifndef _IO_fork
  45 #ifdef _LIBC
  46 #define _IO_fork __vfork
  47 #else
  48 #define _IO_fork vfork /* defined in libiberty, if needed */
  49 #endif
  50 extern _IO_pid_t _IO_fork __P ((void));
  51 #endif
  52
  53 #endif /* _IO_HAVE_SYS_WAIT */
  54
  55 #ifndef _IO_pipe
  56 #ifdef _LIBC
  57 #define _IO_pipe __pipe
  58 #else
  59 #define _IO_pipe pipe
  60 #endif
  61 extern int _IO_pipe __P ((int des[2]));
  62 #endif
  63
  64 #ifndef _IO_dup2
  65 #ifdef _LIBC
  66 #define _IO_dup2 __dup2
  67 #else
  68 #define _IO_dup2 dup2
  69 #endif
  70 extern int _IO_dup2 __P ((int fd, int fd2));
  71 #endif
  72
  73 #ifndef _IO_waitpid
  74 #ifdef _LIBC
  75 #define _IO_waitpid __waitpid
  76 #else
  77 #define _IO_waitpid waitpid
  78 #endif
  79 #endif
  80
  81 #ifndef _IO_execl
  82 #define _IO_execl execl
  83 #endif
  84 #ifndef _IO__exit
  85 #define _IO__exit _exit
  86 #endif
  87
  88 #ifndef _IO_close
  89 #ifdef _LIBC
  90 #define _IO_close __close
  91 #else
  92 #define _IO_close close
  93 #endif
  94 #endif
  95
  96 struct _IO_proc_file
  97 {
  98   struct _IO_FILE_plus file;
  99   /* Following fields must match those in class procbuf (procbuf.h) */
 100   _IO_pid_t pid;
 101   struct _IO_proc_file *next;
 102 };
 103 typedef struct _IO_proc_file _IO_proc_file;
 104
 105 static struct _IO_jump_t _IO_wproc_jumps;
 106
 107 static struct _IO_proc_file *proc_file_chain;
 108
 109 _IO_FILE *
 110 _IO_new_proc_open (fp, command, mode)
 111      _IO_FILE *fp;
 112      const char *command;
 113      const char *mode;
 114 {
 115 #if _IO_HAVE_SYS_WAIT
 116   volatile int read_or_write;
 117   volatile int parent_end, child_end;
 118   int pipe_fds[2];
 119   _IO_pid_t child_pid;
 120   if (_IO_file_is_open (fp))
 121     return NULL;
 122   if (_IO_pipe (pipe_fds) < 0)
 123     return NULL;
 124   if (mode[0] == 'r' && mode[1] == '\0')
 125     {
 126       parent_end = pipe_fds[0];
 127       child_end = pipe_fds[1];
 128       read_or_write = _IO_NO_WRITES;
 129     }
 130   else if (mode[0] == 'w' && mode[1] == '\0')
 131     {
 132       parent_end = pipe_fds[1];
 133       child_end = pipe_fds[0];
 134       read_or_write = _IO_NO_READS;
 135     }
 136   else
 137     {
 138       __set_errno (EINVAL);
 139       return NULL;
 140     }
 141   ((_IO_proc_file *) fp)->pid = child_pid = _IO_fork ();
 142   if (child_pid == 0)
 143     {
 144       int child_std_end = mode[0] == 'r' ? 1 : 0;
 145       struct _IO_proc_file *p;
 146
 147       _IO_close (parent_end);
 148       if (child_end != child_std_end)
 149         {
 150           _IO_dup2 (child_end, child_std_end);
 151           _IO_close (child_end);
 152         }
 153       /* POSIX.2:  "popen() shall ensure that any streams from previous
 154          popen() calls that remain open in the parent process are closed
 155          in the new child process." */
 156       for (p = proc_file_chain; p; p = p->next)
 157         _IO_close (_IO_fileno ((_IO_FILE *) p));
 158
 159       _IO_execl ("/bin/sh", "sh", "-c", command, (char *) 0);
 160       _IO__exit (127);
 161     }
 162   _IO_close (child_end);
 163   if (child_pid < 0)
 164     {
 165       _IO_close (parent_end);
 166       return NULL;
 167     }
 168   _IO_fileno (fp) = parent_end;
 169
 170   /* Link into proc_file_chain. */
 171   ((_IO_proc_file *) fp)->next = proc_file_chain;
 172   proc_file_chain = (_IO_proc_file *) fp;
 173
 174   _IO_mask_flags (fp, read_or_write, _IO_NO_READS|_IO_NO_WRITES);
 175   return fp;
 176 #else /* !_IO_HAVE_SYS_WAIT */
 177   return NULL;
 178 #endif
 179 }
 180
 181 _IO_FILE *
 182 _IO_new_popen (command, mode)
 183      const char *command;
 184      const char *mode;
 185 {
 186   struct locked_FILE
 187   {
 188     struct _IO_proc_file fpx;
 189 #ifdef _IO_MTSAFE_IO
 190     _IO_lock_t lock;
 191 #endif
 192     struct _IO_wide_data wd;
 193   } *new_f;
 194   _IO_FILE *fp;
 195
 196   new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
 197   if (new_f == NULL)
 198     return NULL;
 199 #ifdef _IO_MTSAFE_IO
 200   new_f->fpx.file.file._lock = &new_f->lock;
 201 #endif
 202   fp = &new_f->fpx.file.file;
 203   _IO_no_init (fp, 0, 0, &new_f->wd, &_IO_wproc_jumps);
 204   _IO_JUMPS (fp) = &_IO_proc_jumps;
 205   _IO_new_file_init (fp);
 206 #if  !_IO_UNIFIED_JUMPTABLES
 207   new_f->fpx.file.vtable = NULL;
 208 #endif
 209   if (_IO_new_proc_open (fp, command, mode) != NULL)
 210     return fp;
 211   _IO_un_link (fp);
 212   free (new_f);
 213   return NULL;
 214 }
 215
 216 int
 217 _IO_new_proc_close (fp)
 218      _IO_FILE *fp;
 219 {
 220   /* This is not name-space clean. FIXME! */
 221 #if _IO_HAVE_SYS_WAIT
 222   int wstatus;
 223   _IO_proc_file **ptr = &proc_file_chain;
 224   _IO_pid_t wait_pid;
 225   int status = -1;
 226
 227   /* Unlink from proc_file_chain. */
 228   for ( ; *ptr != NULL; ptr = &(*ptr)->next)
 229     {
 230       if (*ptr == (_IO_proc_file *) fp)
 231         {
 232           *ptr = (*ptr)->next;
 233           status = 0;
 234           break;
 235         }
 236     }
 237
 238   if (status < 0 || _IO_close (_IO_fileno(fp)) < 0)
 239     return -1;
 240   /* POSIX.2 Rationale:  "Some historical implementations either block
 241      or ignore the signals SIGINT, SIGQUIT, and SIGHUP while waiting
 242      for the child process to terminate.  Since this behavior is not
 243      described in POSIX.2, such implementations are not conforming." */
 244   do
 245     {
 246       wait_pid = _IO_waitpid (((_IO_proc_file *) fp)->pid, &wstatus, 0);
 247     }
 248   while (wait_pid == -1 && errno == EINTR);
 249   if (wait_pid == -1)
 250     return -1;
 251   return wstatus;
 252 #else /* !_IO_HAVE_SYS_WAIT */
 253   return -1;
 254 #endif
 255 }
 256
 257 struct _IO_jump_t _IO_proc_jumps = {
 258   JUMP_INIT_DUMMY,
 259   JUMP_INIT(finish, _IO_new_file_finish),
 260   JUMP_INIT(overflow, _IO_new_file_overflow),
 261   JUMP_INIT(underflow, _IO_new_file_underflow),
 262   JUMP_INIT(uflow, _IO_default_uflow),
 263   JUMP_INIT(pbackfail, _IO_default_pbackfail),
 264   JUMP_INIT(xsputn, _IO_new_file_xsputn),
 265   JUMP_INIT(xsgetn, _IO_default_xsgetn),
 266   JUMP_INIT(seekoff, _IO_new_file_seekoff),
 267   JUMP_INIT(seekpos, _IO_default_seekpos),
 268   JUMP_INIT(setbuf, _IO_new_file_setbuf),
 269   JUMP_INIT(sync, _IO_new_file_sync),
 270   JUMP_INIT(doallocate, _IO_file_doallocate),
 271   JUMP_INIT(read, _IO_file_read),
 272   JUMP_INIT(write, _IO_new_file_write),
 273   JUMP_INIT(seek, _IO_file_seek),
 274   JUMP_INIT(close, _IO_new_proc_close),
 275   JUMP_INIT(stat, _IO_file_stat),
 276   JUMP_INIT(showmanyc, _IO_default_showmanyc),
 277   JUMP_INIT(imbue, _IO_default_imbue)
 278 };
 279
 280 static struct _IO_jump_t _IO_wproc_jumps = {
 281   JUMP_INIT_DUMMY,
 282   JUMP_INIT(finish, _IO_new_file_finish),
 283   JUMP_INIT(overflow, _IO_new_file_overflow),
 284   JUMP_INIT(underflow, _IO_new_file_underflow),
 285   JUMP_INIT(uflow, _IO_default_uflow),
 286   JUMP_INIT(pbackfail, _IO_default_pbackfail),
 287   JUMP_INIT(xsputn, _IO_new_file_xsputn),
 288   JUMP_INIT(xsgetn, _IO_default_xsgetn),
 289   JUMP_INIT(seekoff, _IO_new_file_seekoff),
 290   JUMP_INIT(seekpos, _IO_default_seekpos),
 291   JUMP_INIT(setbuf, _IO_new_file_setbuf),
 292   JUMP_INIT(sync, _IO_new_file_sync),
 293   JUMP_INIT(doallocate, _IO_file_doallocate),
 294   JUMP_INIT(read, _IO_file_read),
 295   JUMP_INIT(write, _IO_new_file_write),
 296   JUMP_INIT(seek, _IO_file_seek),
 297   JUMP_INIT(close, _IO_new_proc_close),
 298   JUMP_INIT(stat, _IO_file_stat),
 299   JUMP_INIT(showmanyc, _IO_default_showmanyc),
 300   JUMP_INIT(imbue, _IO_default_imbue)
 301 };
 302
 303 strong_alias (_IO_new_popen, __new_popen)
 304 versioned_symbol (libc, _IO_new_popen, _IO_popen, GLIBC_2_1);
 305 versioned_symbol (libc, __new_popen, popen, GLIBC_2_1);
 306 versioned_symbol (libc, _IO_new_proc_open, _IO_proc_open, GLIBC_2_1);
 307 versioned_symbol (libc, _IO_new_proc_close, _IO_proc_close, GLIBC_2_1);