How can we read each line from a file onto an array?

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

Replies are listed 'Best First'.
Re: how can we read each line from a file onto an array?⭐ by OeufMayo (Curate) on Apr 18, 2001 at 12:37 UTC
`my @lines = <FILE>;` [download] But beware, as the perlfaq 5 says: Whenever you see someone do this: `@lines = <INPUT>;` You should think long and hard about why you need everything loaded at once. It's just not a scalable solution. You might also find it more fun to use the the standard DB_File module's $DB_RECNO bindings, which allow you to tie an array to a file so that accessing an element the array actually accesses the corresponding line in the file.	[reply] [d/l] [select]
Re: how can we read each line from a file onto an array?⭐ by tye (Sage) on Apr 18, 2001 at 17:20 UTC
`my @lines= do { local(*ARGV); @ARGV="filename.txt"; <> };` is one way to avoid having to open the file explicitly, check for errors, and report them.	[reply] [d/l]
Re: how can we read each line from a file onto an array? by davorg (Chancellor) on Apr 18, 2001 at 12:30 UTC
`open FILE, '/path/to/file' or die "Can't open file: $!\n"; my @array = <FILE>;` [download] All very simple :)	[reply] [d/l]
Re: how can we read each line from a file onto an array? by abhishek_akj (Initiate) on Aug 26, 2009 at 10:19 UTC
`my @lines = <FILE>` [download] above loads the whole file at once in memory. Instead, you can do something like `while(my $line=<FILE>){ do_something; }` [download] This code will still traverse the whole file, so wont be faster but it will load only one line at a time in the memory - helpful if you want to parse 4GB file and have only 2 GB RAM ;)	[reply] [d/l] [select]
Re: how can we read each line from a file onto an array? by Clachair (Acolyte) on Apr 24, 2001 at 13:45 UTC
`use IO::File; open my $fhi, '<', $fi or die "$!, Couldn't open file $fi"; my @lines = $fhi->getlines; for my $line ( @lines ) { # Select only those lines with a HTML cell bg color spec; if ( $line =~ /^\s*<td bgcolor/) { push @List, $line; } } close $fhi;` [download]	[reply] [d/l]


The stupid question is the question not asked
	PerlMonks