cdesktopenv/cde/programs/dtmail/libDtMail/Common/Process.C

303 lines
6.6 KiB
C

/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/*
*+SNOTICE
*
*
* $TOG: Process.C /main/6 1998/04/06 13:26:21 mgreess $
*
* RESTRICTED CONFIDENTIAL INFORMATION:
*
* The information in this document is subject to special
* restrictions in a confidential disclosure agreement bertween
* HP, IBM, Sun, USL, SCO and Univel. Do not distribute this
* document outside HP, IBM, Sun, USL, SCO, or Univel wihtout
* Sun's specific written approval. This documment and all copies
* and derivative works thereof must be returned or destroyed at
* Sun's request.
*
* Copyright 1993 Sun Microsystems, Inc. All rights reserved.
*
*+ENOTICE
*/
#if HAVE_CONFIG_H
#include <cde_config.h>
#endif
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#if HAVE_POLL_H
#include <poll.h>
#elif HAVE_SYS_POLL_H
#include <sys/poll.h>
#endif
/*
** file included for INFTIM
*/
#if defined(SunOS)
#include <stropts.h>
#elif defined(_AIX) || defined(__linux__)
#define INFTIM (-1) /* Infinite timeout */
#endif
#include <sys/wait.h>
#include "Process.hh"
#include <DtMail/Threads.hh>
#include <DtMail/IO.hh>
static const int DEFAULT_SIZE = 64 << 10;
void
SetNoBlock(int fd)
{
int flags;
do {
flags = fcntl(fd, F_GETFL);
} while(flags < 0 && errno == EINTR);
if (flags < 0) {
return;
}
flags |= O_NONBLOCK;
int status;
do {
status = fcntl(fd, F_SETFL, flags);
} while (status < 0 && errno == EINTR);
return;
}
int
RunProg(const char * program,
char *const * argv,
const char * stdin_data,
const unsigned long stdin_size,
char ** stdout_data,
unsigned long & stdout_size,
char ** stderr_data,
unsigned long & stderr_size)
{
// See if we are supposed to do I/O with the child.
//
int stdin_fd[2];
int stdout_fd[2];
int stderr_fd[2];
size_t stdout_bufsize = 0;
unsigned long stderr_bufsize = 0;
if (stdin_data) {
pipe(stdin_fd);
SetNoBlock(stdin_fd[1]);
}
if (stdout_data) {
pipe(stdout_fd);
SetNoBlock(stdout_fd[0]);
}
if (stderr_data) {
pipe(stderr_fd);
SetNoBlock(stderr_fd[0]);
}
// We will fork and set up the file descriptors in the
// child.
//
#if defined(POSIX_THREADS)
pid_t child = fork1();
#else
pid_t child = fork();
#endif
if (child < 0) {
return(child);
}
if (child == 0) { // The real child process.
if (stdin_data) {
SafeDup2(stdin_fd[0], STDIN_FILENO);
close(stdin_fd[0]);
close(stdin_fd[1]);
}
if (stdout_data) {
SafeDup2(stdout_fd[1], STDOUT_FILENO);
close(stdout_fd[0]);
close(stdout_fd[1]);
}
if (stderr_data) {
SafeDup2(stderr_fd[1], STDERR_FILENO);
close(stderr_fd[0]);
close(stderr_fd[1]);
}
SafeExecvp(program, argv);
return(child);
}
else { // This is still us.
int stdin_written = 0;
int nfds = 1;
pollfd fds[3];
memset(fds, 0, sizeof(fds));
fds[0].fd = stdin_fd[1];
fds[0].events = POLLOUT;
close(stdin_fd[0]);
if (stdout_data) {
fds[1].fd = stdout_fd[0];
fds[1].events = POLLIN;
nfds = 2;
*stdout_data = (char *)malloc(DEFAULT_SIZE);
stdout_bufsize = DEFAULT_SIZE;
stdout_size = 0;
close(stdout_fd[1]);
} else {
fds[1].fd = -1;
}
if (stderr_data) {
fds[2].fd = stderr_fd[0];
fds[2].events = POLLIN;
nfds = 3;
*stderr_data = (char *)malloc(DEFAULT_SIZE);
stderr_bufsize = DEFAULT_SIZE;
stderr_size = 0;
close(stderr_fd[1]);
} else {
fds[2].fd = -1;
}
// set up the initial events we way we care about. Note that
// fds[1] and fds[2] may not be used -- nfds may be less than 3
while (1) {
int result;
int i;
// check to make sure there is really some work to do
// walk through the fds structure. If we get to the end
// without finding anything to do, i will be == nfds
for (i = 0; i < nfds; i++) {
if (fds[i].fd >= 0) break;
}
if (i == nfds) {
// there was no work to do
break;
}
// we probably don't want to wait forever, so we can try
// and reap the child here, just in case it exits...
result = poll(fds, nfds, INFTIM);
if (result < 0) {
// poll error -- what do we do?
if (errno == EINTR) continue;
// not much else to do -- poll really shouldn't fail...
break;
}
if ((fds[0].revents & POLLOUT) &&
stdin_data && stdin_written < stdin_size) {
int status = SafeWrite(stdin_fd[1], stdin_data + stdin_written,
(size_t) stdin_size - stdin_written);
if (status > 0) {
stdin_written += status;
}
if (stdin_written >= stdin_size) {
// we're done with the input
close(stdin_fd[1]);
fds[0].fd = -1;
fds[0].events = 0;
}
}
// We will now try to read 4K from each requested file
// descriptor.
//
if (stdout_data && (fds[1].revents & POLLIN)) {
int status = SafeRead(stdout_fd[0], *stdout_data + stdout_size,
4096);
if (status < 0 && errno != EAGAIN) {
break;
}
if (status > 0) {
stdout_size += status;
if ((stdout_size + 4096) > stdout_bufsize) {
stdout_bufsize += DEFAULT_SIZE;
*stdout_data = (char *)realloc(*stdout_data, stdout_bufsize);
}
}
}
if (stderr_data && (fds[2].revents & POLLIN)) {
int status = SafeRead(stderr_fd[0], *stderr_data + stderr_size,
4096);
if (status < 0 && errno != EAGAIN) {
break;
}
if (status > 0) {
stderr_size += status;
}
if ((stderr_size + 4096) > stderr_bufsize) {
stderr_bufsize += DEFAULT_SIZE;
*stderr_data =
(char*) realloc(*stderr_data, (size_t) stderr_bufsize);
}
}
if ((fds[0].revents & POLLHUP) ||
(fds[1].revents & POLLHUP) ||
(fds[2].revents & POLLHUP)) {
break;
}
}
int child_stat;
SafeWaitpid(child, &child_stat, 0);
return(child_stat);
}
return(child);
}