fis-gtm/sr_unix/gtm_pipe.c

82 lines
2.1 KiB
C

/****************************************************************
* *
* Copyright 2001, 2011 Fidelity Information Services, Inc *
* *
* This source code contains the intellectual property *
* of its copyright holder(s), and is made available *
* under a license. If you do not know the terms of *
* the license, please stop and do not read further. *
* *
****************************************************************/
/* gtm_pipe.c
Parameters --
command : the command to be executed.
pt : type of the pipe (input or output)
Returns --
-1 : fork() error
-2 : pipe() error
other : the file descriptor serving as one end of the pipe
*/
#include "mdef.h"
#include <sys/types.h>
#include "gtm_fcntl.h"
#include "gtm_stat.h"
#include "gtm_stdio.h"
#include "gtm_unistd.h"
#include "gtm_stdlib.h"
#include "gtm_pipe.h"
#include "eintr_wrappers.h"
#include "gtmio.h"
GBLDEF uint4 pipe_child;
int gtm_pipe(char *command, pipe_type pt)
{
int pfd[2], child, parent;
int dup2_res, rc;
pid_t child_pid;
parent = (int)pt;
child = 1 - parent;
if (0 > pipe(pfd))
{
PERROR("pipe : ");
return -2;
}
if (-1 == (child_pid = fork()))
{
PERROR("fork : ");
return -1;
} else if (0 == child_pid)
{ /* child process */
CLOSEFILE_RESET(pfd[parent], rc); /* resets "pfd[parent]" to FD_INVALID */
DUP2(pfd[child], child, dup2_res);
CLOSEFILE_RESET(pfd[child], rc); /* resets "pfd[child]" to FD_INVALID */
/* We should have used exec instead of SYSTEM. Earlier it was followed by exit(0), which calls exit_handler.
* So both child and parent will do exit handling. This can make ref_cnt < 0, or, it can release semaphores,
* which we should not release until parent exists. So we just call _exit(0). Add the do nothing if to
* keep compiler happy since exiting anyway.
*/
if (-1 == SYSTEM(command));
_exit(0); /* just exit from here */
} else
{ /* parent process */
pipe_child = child_pid;
CLOSEFILE_RESET(pfd[child], rc); /* resets "pfd[child]" to FD_INVALID */
return pfd[parent];
}
assert(FALSE);
/* It should never get here, just to keep compiler happy. */
return -3;
}