I want to have a Perl script that receives a file and do some computation based on it.
Here is my try:
Perl.pl
#!/usr/bin/perl
use strict;
use warnings;
my $book = <STDIN>;
print $book;
Here is my execution of the script:
./Perl.pl < textFile
My script only prints the first line of textFile. Who can I load all textFile into my variable $book?
I want the file to be passed in that way, I do not want to use Perl's open(...)
Assigning a value from a file handle to a scalar pulls it one line at a time.
You can either:
while loop to append the lines one by one until there are none left or$/ (to undef) to change your script's idea of what constitutes a line. There is an example of the latter in perldoc perlvar (read it as it explains best practises for changing it).Also you can use Path::Class for easy. It is a wrapper for many file manipulation modules.
For your purpose:
#! /usr/bin/perl
use Path::Class qw/file/;
my $file = file(shift @ARGV);
print $file->slurp;
You can run it by:
./slurp.pl textFile
The answer you're looking for is in the Perl FAQ.