ts2dur.pl

#!/usr/bin/perl -w
# ts2dur -- Annotates a timestamp-per-line input with the duration between two lines
#
# Author: Jaeho Shin <netj@sparcs.org>
# Created: 2017-02-17
##
use strict;
use POSIX qw(strftime);
use Date::Parse;
use Time::HiRes;

# defaults to expecting ISO8601-ish timestamp format: YYYY-mm-dd HH:MM:SS.SSSSSS
our $TS_FMT = $ENV{TS2DUR_TS_FORMAT} || "%Y-%m-%d %H:%M:%S.uuuuuu";
our $TS_BEGIN = $ENV{TS2DUR_TS_FROM} || 0;
our $TS_END   = $ENV{TS2DUR_TS_TO}   || $TS_BEGIN + length(strftime($TS_FMT, localtime()));
# duration precision
our $PRECISION = $ENV{TS2DUR_DUR_PREC} || 10;
# whether duration starts at the first line or second line
our $DURATION_ON_THIS_LINE = $ENV{TS2DUR_DUR_AFTER} || 0;

my $last_ts;
my $last_line;
sub print_this_line_with_duration {
    my $ts_str = shift;
    my $line = shift;
    my $ts = defined $ts_str ? str2time($ts_str) : undef;
    if (defined $line) {
        my $duration = defined $last_ts ? (sprintf "%0.${PRECISION}f", $ts - $last_ts) : " " x $PRECISION;
        printf "%s\t%s", $duration, $line;
    }
    $last_ts = $ts;
}
sub print_last_line_with_duration {
    my $ts_str = shift;
    my $line = shift;
    my $ts = defined $ts_str ? str2time($ts_str) : undef;
    if (defined $last_line) {
        my $duration = defined $ts ? (sprintf "%0.${PRECISION}f", $ts - $last_ts) : " " x $PRECISION;
        printf "%s\t%s", $duration, $last_line;
    }
    $last_ts = $ts;
    $last_line = $line;
}

my $print_line_with_duration =
    $DURATION_ON_THIS_LINE ? \&print_this_line_with_duration
                           : \&print_last_line_with_duration
                           ;

while (my $line = <>) {
    my $ts_str = substr($line, $TS_BEGIN, $TS_END);
    $print_line_with_duration->($ts_str, $line);
}
$print_line_with_duration->();