Parsing a date time string

bangor has asked for the wisdom of the Perl Monks concerning the following question:

In my script I need to accept date time strings in three formats:

2014-07-12
2014-07-12 1:00
2014-07-12 01:00
[download]

In this example I need to change "1:00" to "01:00" before passing to a DB query. This is how I am doing it:

sub parse_time {
    my $time = shift;
    return $time unless $time =~ m/\d{1,2}:\d{2}$/;
    return $time if $time =~ m/\d{2}:\d{2}$/;
    $time =~ s/(\d{1}:\d{2})$/0$1/;
    return $time;
}
[download]

It works, but it feels kludgy - any advice appreciated.

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Re: Parsing a date time string by Corion (Patriarch) on Aug 02, 2014 at 16:35 UTC
Why not fix the time unconditionally? `sub fix_time { my( $time )= @_; $time =~ s/^(\d:\d\d)$/0$1/; return $time };` [download] This replaces (if it finds) the leading single-digit number with a zero-padded number.	[reply] [d/l]
Re^2: Parsing a date time string by bangor (Monk) on Aug 02, 2014 at 16:56 UTC
Thanks Corion, far more elegant. I made a small adjustment so it could accept the whole string: `sub fix_time { my $time = shift; $time =~ s/\s(\d:\d\d)$/ 0$1/; return $time; }` [download]	[reply] [d/l]
Re: Parsing a date time string by Lennotoecom (Pilgrim) on Aug 02, 2014 at 18:44 UTC
`while (<DATA>){ printf "%04d-%02d-%02d %02d:%02d\n", m/\d+/g; } __DATA__ 2014-07-1 2014-7-09 1:3 2014-07-12 01:5` [download] output ! `2014-07-01 00:00 2014-07-09 01:03 2014-07-12 01:05` [download]	[reply] [d/l] [select]
Re: Parsing a date time string by CountZero (Bishop) on Aug 02, 2014 at 22:48 UTC
DateTime::Format::Natural can read many different formats of date and time strings and returns a `DateTime object`. CountZero A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James My blog: Imperial Deltronics	[reply] [d/l]