hdf5/bin/runbkgprog
David Young 7c82abc3ff Not every system has perl installed in /usr/bin/, so change the shebang
(#!) line to `/usr/bin/env perl` to locate perl on the PATH.

Everything after the first pathname in the shebang line is treated as
a single argument to the command interpreter (/usr/bin/env "perl -w"),
and there is not ordinarily any such program as "perl -w".  So if the
old shebang line used an option such as `-w`, add a `use warnings;`
statement to the script---note that the semantics change slightly.
`bin/destdep` uses a trick to pass `-p` to `/usr/bin/env perl`.  It
couldn't hurt to use the same trick to pass `-w`.

With these changes, `sh autogen.sh` runs on NetBSD.  It ought to still
work on every other system HDF5 supports, too.
2019-10-03 16:01:40 -05:00

89 lines
2.5 KiB
Perl
Executable File

#!/usr/bin/env perl
require 5.003;
use warnings;
$indent=4;
#
# Copyright by The HDF Group.
# Copyright by the Board of Trustees of the University of Illinois.
# All rights reserved.
#
# This file is part of HDF5. The full HDF5 copyright notice, including
# terms governing use, modification, and redistribution, is contained in
# the COPYING file, which can be found at the root of the source code
# distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.
# If you do not have access to either file, you may request a copy from
# help@hdfgroup.org.
#
# Run program in background
#
use warnings;
use strict;
use Carp;
use Time::HiRes;
use POSIX 'setsid';
my $child_pid;
my $child_proc;
my $cmd = $ARGV[0];
my $debug = 1;
print "\nStart child process\n";
start_child();
print "\nStarted child process\n";
sub start_child {
die "cannot execute cmd: $cmd" unless -x $cmd;
if ($^O eq 'MSWin32') { # Windows
require Win32::Process;
Win32::Process::Create($child_proc, $cmd, $cmd, 0, 0, ".") || confess "Could not spawn child: $!";
$child_pid = $child_proc->GetProcessID();
}
else { # Unix
$SIG{CHLD} = 'IGNORE';
$child_pid = fork();
unless (defined $child_pid) {
confess "Could not spawn child (Unix): $!";
}
if ($child_pid == 0) { # child
unless ($debug) {
open STDIN, "<", "/dev/null" or die "Can't read /dev/null: $!";
open STDOUT, ">", "/dev/null" or die "Can't write /dev/null: $!";
}
setsid or warn "setsid cannot start a new session: $!";
unless ($debug) {
open STDERR, '>&STDOUT' or die "Can't dup stdout: $!";
}
local $| = 1;
unless (exec($cmd)) {
confess "Could not start child: $cmd: $!";
CORE::exit(0);
}
}
# parent
$SIG{CHLD} = 'DEFAULT';
}
# catch early child exit, e.g. if program path is incorrect
sleep(1.0);
POSIX::waitpid(-1, POSIX::WNOHANG()); # clean up any defunct child process
if (kill(0,$child_pid)) {
print "\nStarted child process id $child_pid\n";
}
else {
warn "Child process exited quickly: $cmd: process $child_pid";
}
}
sub stop_child
{
if ($^O eq 'MSWin32') { # Windows
Win32::Process::KillProcess($child_pid,0);
}
else { # Unix
kill 9, $child_pid || warn "could not kill process $child_pid: $!";
}
print "Stopped child process id $child_pid\n";
}