How do I test for a blank line when reading from a file?

bravismore has asked for the wisdom of the Perl Monks concerning the following question: ⭐ (files)

Replies are listed 'Best First'.
Re: How do I test for a blank line when reading from a file?⭐ by merlyn (Sage) on Oct 11, 2000 at 20:54 UTC
`print "it's blank" unless /\S/;` [download] (This assumes that a line consisting of only whitespace characters is considered blank.)	[reply] [d/l]
Re: How do I test for a blank line when reading from a file? by thanos1983 (Parson) on May 29, 2014 at 21:01 UTC
Extending runrig's answer to cover the case where "blank" could include whitespace characters (as merlyn's answer already does, negatively): Use `/^\s$/` As in: `while (<>) { print "blank line detected\n" if /^\s$/; }` [download]	[reply] [d/l] [select]
Re: How do I test for a blank line when reading from a file? by runrig (Abbot) on Oct 11, 2000 at 20:52 UTC
If by "blank" you mean "empty", then `/^$/`, as in: `while (<>) { print "blank line detected\n" if /^$/; }` [download]	[reply] [d/l] [select]
Re: How do I test for a blank line when reading from a file? by abhishek_akj (Initiate) on Aug 26, 2009 at 10:28 UTC
`while (<>) { print __LINE__ " \| This line is blank\n" if /^$/; }` [download] A little friendlier output Originally posted as a Categorized Answer.	[reply] [d/l]