How can I pass a variable from called perl script to calling perl script?

Question

I have a parent/calling shell script "parent.sh", this script is calling a perl script "child.pl". In "child.pl", I have "$x = 1000", how can I return x to the parent/calling "parent.sh" without using exit status?

Answer 1

Backticks allow you to capture the output of a child.

my $stdout_of_child = `perl -e'print 1000'`;

die( "Can't launch child: $!\n" )                   if $? == -1;
die( "Child killed by signal ".( $? & 0x7F )."\n" ) if $? & 0x7F;
die( "Child exited with error ".( $? >> 8 )."\n" )  if $? >> 8;

See qx in perlop for documentation.

See also capturex from IPC::System::Simple, and IPC::Run.

To exchange more complicated data structures, you could serialize the data using JSON, YAML, etc.