When would `local $_' in a function ruin your day?

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When your caller was in the middle for a while(m//g) loop
The /g state on a global variable is not protected by running local on it. That'll teach you to stop using locals. Too bad $_ can't be the target of a my() -- yet.

2013-09-20, 2563👍, 0💬

How do I replace every <TAB> character in a file with a comma?
How do I replace every <TAB> character in a file with a comma? perl -pi.bak -e 's/\t/,/g' myfile.txt 2013-09-18, 3359👍, 0💬

How do I print the entire contents of an array with Perl?
How do I print the entire contents of an array with Perl? To answer this question, we first need a sample array. Let's assume that you have an array that contains the name of baseball teams, like this: @teams = ('cubs', 'reds', 'yankees', 'dodgers'); If you just want to print the array with the arra... 2013-09-24, 2710👍, 0💬

How to concatenate strings with Perl?
How to concatenate strings with Perl? Method #1 - using Perl's dot operator: $name = 'checkbook'; $filename = "/tmp/" . $name . ".tmp"; Method #2 - using Perl's join function $name = "checkbook"; $filename = join "", "/tmp/", $name, ".tmp"; Method #3 - usual way of concatenating strings $filename = ... 2013-09-19, 2707👍, 0💬

How do I read command-line arguments with Perl?
How do I read command-line arguments with Perl? With Perl, command-line arguments are stored in the array named @ARGV. $ARGV[0] contains the first argument, $ARGV[1] contains the second argument, etc. $#ARGV is the subscript of the last element of the @ARGV array, so the number of arguments on the c... 2013-09-19, 2660👍, 0💬

How do I do < fill-in-the-blank > for each element in an array?
How do I do < fill-in-the-blank > for each element in an array? #!/usr/bin/perl -w @homeRunHitters = ('McGwire', 'Sosa', 'Maris', 'Ruth'); foreach (@homeRunHitters) { print "$_ hit a lot of home runs in one year\n"; } 2013-09-16, 2648👍, 0💬

What happens to objects lost in "unreachable" memory..... ?
What happens to objects lost in "unreachable" memory..... ? What happens to objects lost in "unreachable" memory, such as the object returned by Ob->new() in `{ my $ap; $ap = [ Ob->new(), \$ap ]; }' ? Their destructors are called when that interpreter thread shuts down. When the interp... 2013-09-20, 2626👍, 0💬

Assume that $ref refers to a scalar, an array, a hash or to some nested data structure. Explain the following statements:
Assume that $ref refers to a scalar, an array, a hash or to some nested data structure. Explain the following statements: $$ref; # returns a scalar $$ref[0]; # returns the first element of that array $ref- > [0]; # returns the first element of that array @$ref; # returns the contents of that ... 2013-09-23, 2613👍, 0💬

How do you match one letter in the current locale?
How do you match one letter in the current locale? /[^\W_\d]/ We don't have full POSIX regexps, so you can't get at the isalpha() <ctype.h> macro save indirectly. You ask for one byte which is neither a non-alphanumunder, nor an under, nor a numeric. That leaves just the alphas, which ... 2013-09-23, 2608👍, 0💬

When would `local $_' in a function ruin your day?
When would `local $_' in a function ruin your day? When your caller was in the middle for a while(m//g) loop The /g state on a global variable is not protected by running local on it. That'll teach you to stop using locals. Too bad $_ can't be the target of a my() -- yet. 2013-09-20, 2564👍, 0💬

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