who-open-file

#! /usr/bin/env perl

# Copyright (C) YangBingwu (detailyang)

use 5.0006001;
use strict;
use warnings;
use Getopt::Std qw ( getopts );

sub usage();

my %opts;

getopts("ha:t:f:", \%opts) or die usage();

if ($opts{h}) {
    print usage();
    exit;
}

my $stap_args = $opts{a} || '';
getopts('df:t:', \%opts) or die usage();

my $time = $opts{t} || 10000;
if ($time !~ /^\d+$/) {
   die "Bad -t options value \"$time\": not look like time";
}

my $filename = $opts{f} || '.*';

my $preamble = <<_EOC_;
probe begin {
    printf("Collecting who is opening filename $filename \\r\\n\\r\\n");
}
_EOC_

my $stap_src = <<_EOC_;
$preamble

probe syscall.open {
    if (filename =~ %( \$# == 0 %? ".*" %: \@1 %)) {
        printf("%s(%d) is opening the filename: %s\\r\\n", execname(), pid(), filename)
    }
}

probe timer.ms($time) {
    exit()
}
_EOC_

if ($opts{d}) {
    print $stap_src;
    exit();
}

open my $in, "| stap $stap_args --skip-badvars - $filename";

print $in $stap_src;

close $in;


sub usage() {
    return <<'_EOC_';
Usage:
    who-open-file [optoins]
Options:
    -a <args>           Pass extra arguments to the stap utility.
    -t <time>(ms)       Time(ms) to execute.
    -f <filename>       Filename to open.
    -d                  Dump out the systemtap script source.
    -h                  Print this usage.
Examples:
    who-open-file -t 10000 -f xx
_EOC_
}