seth@ctr.columbia.edu (Seth Robertson) (12/20/89)
I had the same problem under SunOS 4.0 (just closing stdin/out/err didn't
work) so I wrote a small program to close everything. The major part of
the program is this:
for (fd = 0; fd < getdtablesize(); fd++)
close (fd);
everything else is just support and other things which are nice but
not necessary.
Here is the complete program:
[Usage: rsh -n host unrsh rprocess]
#! /bin/sh
# This is a shell archive. Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file". To overwrite existing
# files, type "sh file -c". You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g.. If this archive is complete, you
# will see the following message at the end:
# "End of shell archive."
# Contents: /home/sirius/seth/c/unrsh.c
# Wrapped by seth@sirius on Tue Dec 19 11:04:17 1989
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f '/home/sirius/seth/c/unrsh.c' -a "${1}" != "-c" ; then
echo shar: Will not clobber existing file \"'/home/sirius/seth/c/unrsh.c'\"
else
echo shar: Extracting \"'/home/sirius/seth/c/unrsh.c'\" \(1750 characters\)
sed "s/^X//" >'/home/sirius/seth/c/unrsh.c' <<'END_OF_FILE'
X/*
X** Program to unrshfy a process
X**
X** (if a process was started by rsh, this will make the rsh stuff die)
X**
X** This program has been tested under SunOS4.0
X**
X** This program has been placed in the public domain. There are no
X** restrictions on its distribution, and no one is responsible for
X** anything that might occur do to the use of this program.
X*/
X
X/* I probably don't need all of these... */
X#include <stdio.h>
X#include <ctype.h>
X#include <sys/types.h>
X#include <sys/stat.h>
X#include <sys/file.h>
X#include <time.h>
X#include <errno.h>
X#include <fcntl.h>
X#include <signal.h>
X#include <sys/file.h>
X#include <sys/ioctl.h>
X#include <sys/param.h>
X
X
Xmain(argc,argv,envp)
X
Xint argc;
Xchar **argv;
Xchar **envp;
X
X{
X int pid; /* Process id of child */
X register int fd; /* File desc. */
X int err = 0; /* Error variable */
X
X /* bail on a controlling tty, if any */
X if ((fd = open ("/dev/tty", O_RDWR)) >= 0)
X {
X err = (err << 1) | (ioctl (fd, TIOCNOTTY, (char *) 0) == -1);
X err = (err << 1) | (close (fd) == -1);
X }
X
X /* The following command will get rid of the stupid in.rshd
X * process
X */
X /* close all files */
X for (fd = 0; fd < getdtablesize(); fd++)
X close (fd);
X
X /* Open stdin/out/err */
X err = (err << 1) | (open ("/dev/null", O_RDONLY) == -1);
X err = (err << 1) | (open ("/dev/null", O_WRONLY) == -1);
X err = (err << 1) | (open ("/dev/null", O_WRONLY) == -1);
X
X /* detach from process group */
X err = (err << 1) | (setpgrp (0, (pid = getpid ())) == -1);
X
X
X /* check for errors before running program */
X err <<= 1;
X
X if (err) /* Run the program if no error */
X exit(1); /* Not much we can do */
X
X argv++;
X
X execvp(*argv, argv);
X
X perror("s: execvp");
X exit(-1);
X}
END_OF_FILE
if test 1750 -ne `wc -c <'/home/sirius/seth/c/unrsh.c'`; then
echo shar: \"'/home/sirius/seth/c/unrsh.c'\" unpacked with wrong size!
fi
# end of '/home/sirius/seth/c/unrsh.c'
fi
echo shar: End of shell archive.
exit 0
-Seth Robertson
seth@ctr.columbia.edu