Re^2: Making a variable from a number in front of a string

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Re^3: Making a variable from a number in front of a string by Laurent_R (Canon) on Jul 15, 2016 at 17:53 UTC
The `<DATA>` file handle makes it possible to read the `__DATA__` section at the end of the program, i.e. in this case: `__DATA__ (1) Preface What is this all about. (2) Summary of Significant Accounting Policies Revenue Recognition Revenue is recognized at the time goods are sold and shipped. (3) Long-term Debt` [download] It simulates another file and it is a way to quickly test programs without having to create a separate test input file	[reply] [d/l] [select]
Re^4: Making a variable from a number in front of a string by Marshall (Canon) on Jul 15, 2016 at 18:22 UTC
The DATA file handle is actually even a bit cooler than that. To set this up, Perl opens the program for read and then seeks to the first byte after the __DATA__ line. Reading from DATA means that you are actually reading the program file. It is possible for the program to "read itself", i.e.: `#!/usr/bin/perl use warnings; use strict; ## DEMO of reading myself seek (DATA,0,0) or die "unable to seek $!"; print while <DATA>; __DATA__ some data would go here` [download] To re-read the DATA section, you could use a tell() to figure out where the initial DATA byte is and then later seek back to that initial byte offset.	[reply] [d/l]
Re^3: Making a variable from a number in front of a string by Marshall (Canon) on Jul 15, 2016 at 18:35 UTC
Maybe we didn't give you a crystal clear reply. First, the program should run using the data segment. Then take the data after __DATA__ and put that into "somefile". In the program, you need to add at the beginning, `open FILE, '<', "somefile" or die "unable to open file $!";` [download] Now put FILE everywhere that DATA appears in the program. You will now be reading "somefile" on the disk instead of the __DATA__ section.	[reply] [d/l]