What is $? In Perl script?

$? is the error code of the child process (perform_task.sh). In the case of your script the return code is shifted eight bits to the right and the result compared with 0. This means the run is considered a failure only if the returned code is > than 255. Follow this answer to receive notifications.

How do I return a value from a subroutine in Perl?

return() function in Perl returns Value at the end of a subroutine, block, or do function. Returned value might be scalar, array, or a hash according to the selected context.

What is Perl strict?

The use strict statement is called pragma and it can be placed at the beginning of the script like this: #!/usr/local/bin/perl use strict; What does it do? It forces you to code properly to make your program less error-prone. For example: It forces you to declare variables before you use them.

How do I compile the Perl program?

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  1. Install PAR::Packer . Example for *nix: sudo cpan -i PAR::Packer. For Strawberry Perl for Windows or for ActivePerl and MSVC installed: cpan -i PAR::Packer.
  2. Pack it with pp . It will create an executable named “example” or “example.exe” on Windows. pp -o example example.pl.

What does QW do in Perl?

The qw operator in Perl is used to extract each element of the given string as it is in an array of elements in single-quote ( ‘ ‘ ). This function stands for quote word because it considers each word of the given string as it is quoted like qw(Geeks for Geeks) is equivalent to (‘Geeks’, ‘for’, ‘Geeks’).

Can a subroutine return a value?

A subroutine does not have to return a value, but when it does, it sends back the value with the RETURN instruction. The calling program receives the value in the REXX special variable named RESULT. A function must return a value.

How do I run a Perl script in Linux?

There are many ways to run Perl scripts on Linux:

  1. Run the “perl” command with the Perl script included in the command line.
  2. Run the “perl” command with the Perl script supplied from the standard input stream.
  3. Run the “perl” command with the Perl script supplied in a file.
  4. Run Perl script files as commands.

What is chop and chomp in Perl?

Perl’s chop and chomp functions can often be a source of confusion. Not only do they sound similar, they do similar things. Unfortunately, there is a critical difference—​chop removes the last character of the string completely, while chomp only removes the last character if it is a newline.