If you want to circumvent the shell you can fork/exec yourself (at least on Unix), and reopen STDOUT in the child process to the file you want1: 

sub my_sys {
    my $out = pop;
    my $pid = fork();  die "couldn't fork" unless defined $pid;
    if ($pid) {
        wait;
    } else {
        close STDOUT;
        open STDOUT, ">", $out or die "open '$out' failed: $!";
        exec @_;
        die "exec failed: $!";
    }
}

my_sys("/bin/echo", "foo", "bar",  "std.out");

[download]
$ ./935901.pl
$ cat std.out
foo bar

[download]

1 Note that this doesn't work for Perl's "memory" filehandles, because they don't have an associated system file descriptor. Also note that fileno(STDOUT) must be 1, because that's the file descriptor your C program is going to send its stdout to.

In reply to Re: Trying to get an external c program to print to a file by Eliya
in thread Trying to get an external c program to print to a file by akrrs7

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