perl

Why is grep command not showing any output in Perl?

I have an array @files in which I have multiple .txt files. I am trying to grep all the lines that have the pattern "/home/[a-z]+" from the starting of the lines in those files. I am trying the below approach:

my @lines = grep (/^\/home\/[a-z]+/, @files);
chomp(@lines);
my @line = uniq(@lines);

but I do not get anything in the output when I try to print @lines.

What am I doing wrong in the grep command?

Solution

  • Please see the following code sample which demonstrates an approach you have chosen.

    Note: there is no need to use uniq(@lines) as filesystem assumes uniq filenames in it's organization

    use strict;
use warnings;
use feature 'say';

my @files = <DATA>;
my @lines = grep( m!^/home/[a-z]+/!, @files);

say @lines;

__DATA__
/home/alex/work/samples
/home/philip/doc/asterix
/home/maria/bin/quick_search.c
/bin/grep
/sbin/test

    Output

    /home/alex/work/samples
/home/philip/doc/asterix
/home/maria/bin/quick_search.c

    Sample code to filter matching pattern for list of files stored in an array @files.

    use strict;
use warnings;
use feature 'say';

my @files = qw/abc.txt, bcd.txt, cde.txt/;
my @lines;

for my $file (@files) {
    my @temp;
    
    open my $fh, '<', $file
        or die "Couldn't open $file";
    @temp = grep( m!^/home/[a-z]+/!, <$fh>);    
    close $fh;
    
    @lines = (@lines, @temp);
}

chomp(@lines);

say for @lines;