Hello List,
as part of a Perl script of mine, I want to execute a program, get its
return code AND capture its output on both STDERR and STDOUT. I tried
IO::Handle, but that only gives me STDOUT and not the return code. Using
qr//, I cannot read linewise and have to load the complete program's output
into memory first, which I want to avoid. (Please feel free to correct me
on anything of the above.)
What I tried to archive now can be summarized in this little script:
my $stdout = IO::File->new('stdout', 'w');
my $stderr = IO::File->new('stderr', 'w');
my $pid = fork();
die("Could not fork, stopping") if(not defined $pid);
if(0 == $pid) {
*STDOUT = $stdout;
*STDERR = $stderr;
system("df", "-h");
my $rc = $?;
$stdout->flush(););
exit($rc << 127););
} else {
print "Parent.\n";;
wait();
print "RC=$?\n";
}
$stdout->close();
$stderr->close();
That does not, however, work as expected. I do get STDERR's output (if I,
for example, change the command in system() to something that does not
work, e. g. system("df", "garbage", "-FOO"); the error is to be found in
the stderr file), but not the output on STDOUT -- that is printed out on
screen just as usual.
What am I missing here? How can I do a fork, re-open STDOUT/STDERR to write
to an instance of IO::Handle, and get the return code?
Thanks for any hints.
-- Eric
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