Get time difference of two dates using awk

awkdateperl

I have a file of size 7GB. Now have two date time in that I want to use awk to get this difference of time between that two DateTime.

Below is how my files look like:

A          B      C      D         E
18/06/28 09:19:07 295  141536 18-06-28 09:17:47
18/06/28 09:20:07 268  1160   18-06-28 09:18:58
18/06/28 09:21:07 317  1454   18-06-28 09:19:47
18/06/28 09:22:07 275  1491   18-06-28 09:20:59
18/06/28 09:23:07 320  1870   18-06-28 09:21:07
18/06/28 09:24:07 310  1869   18-06-28 09:22:30
18/06/28 09:25:07 150   693   18-06-28 09:23:28
18/06/28 09:26:07 414  2227   18-06-28 09:24:34

I want the difference between (AB) – (E).

I tried this :

cat filename | awk -F " " '{print date -d ($1$2)-($5)}'

Output should be the time difference between the two datetime. Like for the first row difference will be 1min 20sec

Best Answer

Using GNU awk:

gawk '
  function dt2epoch(date, time,      timestr) {
    timestr = "20" substr(date,1,2) " " substr(date,4,2) " " substr(date,7,2) \
               " " substr(time,1,2) " " substr(time,4,2) " " substr(time,7,2)
    return mktime(timestr)
  }
  function epoch2hms(t) {
    return strftime("%H:%M:%S", t, 1)
  }
  function abs(n) {return n<0 ? -1*n : n}
  NR == 1 {next}
  { print epoch2hms(abs(dt2epoch($5,$6) - dt2epoch($1,$2))) }
' file

outputs

00:01:20
00:01:09
00:01:20
00:01:08
00:02:00
00:01:37
00:01:39
00:01:33

with perl, I'd use the DateTime ecosystem:

perl -MDateTime::Format::Strptime -lane '
    BEGIN {$f = DateTime::Format::Strptime->new(pattern => "%y-%m-%d %H:%M:%S")}
    next if $. == 1;
    $F[0] =~ s{/}{-}g;
    $t1 = $f->parse_datetime("$F[0] $F[1]");
    $t2 = $f->parse_datetime("$F[4] $F[5]");
    $d = $t1->subtract_datetime($t2);
    printf "%02d:%02d:%02d\n", $d->hours, $d->minutes, $d->seconds;
' file

A much faster perl version, that does not require any non-core modules

perl -MTime::Piece -lane '
    next if $. == 1;
    $t1 = Time::Piece->strptime("$F[0] $F[1]", "%y/%m/%d %H:%M:%S");
    $t2 = Time::Piece->strptime("$F[4] $F[5]", "%y-%m-%d %H:%M:%S");
    $diff = gmtime(abs($t1->epoch - $t2->epoch));
    print $diff->hms;
' file

or, alternate output:

$ perl -MTime::Piece -lane '
    next if $. == 1;
    $t1 = Time::Piece->strptime("$F[0] $F[1]", "%y/%m/%d %H:%M:%S");
    $t2 = Time::Piece->strptime("$F[4] $F[5]", "%y-%m-%d %H:%M:%S");
    print abs($t1 - $t2)->pretty;
' file
1 minutes, 20 seconds
1 minutes, 9 seconds
1 minutes, 20 seconds
1 minutes, 8 seconds
2 minutes, 0 seconds
1 minutes, 37 seconds
1 minutes, 39 seconds
1 minutes, 33 seconds
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