NetBSD/gnu/dist/libio/iopopen.c

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/* 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)
};