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/* Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
*/
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/resource.h>
#define import_kernel
#define import_knames
#define import_error
#define import_spp
#include <iraf.h>
static int lastsig;
extern int pr_onint(int usig, int *hwcode, int *scp);
extern void pr_enter (int pid, int inchan, int outchan);
extern int pr_wait (int pid);
/* ZOSCMD -- Send a (machine dependent) command to the host operating
* system. If nonnull stdout or stderr filenames are given, try to spool
* the output in these files.
*/
int
ZOSCMD (
PKCHAR *oscmd,
PKCHAR *stdin_file,
PKCHAR *stdout_file,
PKCHAR *stderr_file,
XINT *status
)
{
char *shell, *sh = "/bin/sh";
char *sin, *sout, *serr, *cmd;
struct rlimit rlim;
int maxfd, fd, pid;
struct sigaction oldact;
extern int _u_fmode(int mode);
cmd = (char *)oscmd;
sin = (char *)stdin_file;
sout = (char *)stdout_file;
serr = (char *)stderr_file;
/* The POSIX shell SH is used if the first character of the cmd
* is '!' or if the user does not have SHELL defined in their
* environment.
*/
if (*cmd == '!') {
shell = sh;
cmd++;
} else if ((shell = getenv ("SHELL")) == NULL)
shell = sh;
sigaction (SIGINT, NULL, &oldact);
while ((pid = fork()) == ERR)
sleep (2);
if (pid == 0) {
/* Child.
*/
/* Run the system call. Let child inherit the parents standard
* input unless redirected by nonnull stdin_file. Set standard
* output and error output streams if filenames given, else write
* to same files (i.e., terminal) as parent.
*/
if (*sin != EOS) { /* stdin */
fd = open (sin, O_RDONLY);
if (fd == ERR) {
fprintf (stderr, "cannot open `%s'\n", sin);
_exit (1);
}
close (0); dup (fd); close (fd);
}
if (*sout != EOS) { /* stdout */
fd = creat (sout, _u_fmode(FILE_MODEBITS));
if (fd == ERR)
fprintf (stderr, "cannot create `%s'\n", sout);
else {
close (1); dup (fd); close (fd);
}
}
if (*serr != EOS) { /* stderr */
/* If stdout and stderr are to go to the same file,
* dup stdout file descriptor as stderr.
*/
if (strcmp (sout, serr) == 0) {
close (2); dup (1);
} else {
fd = creat (serr, _u_fmode(FILE_MODEBITS));
if (fd == ERR)
fprintf (stderr, "cannot create `%s'\n", serr);
else {
close (2); dup (fd); close (fd);
}
}
}
if (getrlimit (RLIMIT_NOFILE, &rlim))
maxfd = MAXOFILES;
else
maxfd = rlim.rlim_cur;
/* Arrange for the local file descriptors of the parent to be closed
* in the child if the exec succeeds. If this is not done the child
* may run out of file descriptors.
*/
for (fd=3; fd < min(MAXOFILES,maxfd); fd++)
fcntl (fd, F_SETFD, 1);
/* Spawn a shell to execute the command.
*/
/* Setting old_sigint here doesn't make sense if we will be
* execl-ing a different process. Use SIG_DFL instead.
signal (SIGINT, old_sigint);
*/
signal (SIGINT, SIG_DFL);
execl (shell, shell, "-c", cmd, (char *) 0);
/* NOTREACHED (unless execl fails) */
_exit (1);
}
/* Parent: wait for child to finish up. Parent process should ignore
* interrupts; OS process will handle interrupts and return at the
* proper time. The parent is out of the picture while the OS process
* is running (except for the pr_onint interrupt handler, below).
*/
pr_enter (pid, 0, 0);
lastsig = 0;
*status = pr_wait (pid);
/* If the OS command was interrupted, ignore its exit status and return
* the interrupt exception code to the calling program. Do not return
* the interrupt code unless an interrupt occurs.
*/
if (*status == SYS_XINT)
*status = 1;
if (lastsig == SIGINT)
*status = SYS_XINT;
sigaction (SIGINT, &oldact, NULL);
return (XOK);
}
/* PR_ONINT -- Special interrupt handler for ZOSCMD. If the OS command is
* interrupted, post a flag to indicate this to ZOSCMD when the pr_wait()
* returns.
*/
int
pr_onint (
int usig, /* SIGINT, SIGFPE, etc. */
int *hwcode, /* not used */
int *scp /* not used */
)
{
lastsig = usig;
/* return to wait() */
return (XOK);
}
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