! Aware to Perl: How can I call backticks without shell processing?

RocketAware > Perl >

How can I call backticks without shell processing?

Tips: Browse or Search all pages for efficient awareness of Perl functions, operators, and FAQs.

Home

Search Perl pages

Subjects

By activity
Professions, Sciences, Humanities, Business, ...

User Interface
Text-based, GUI, Audio, Video, Keyboards, Mouse, Images,...

Text Strings
Conversions, tests, processing, manipulation,...

Math
Integer, Floating point, Matrix, Statistics, Boolean, ...

Processing
Algorithms, Memory, Process control, Debugging, ...

Stored Data
Data storage, Integrity, Encryption, Compression, ...

Communications
Networks, protocols, Interprocess, Remote, Client Server, ...

Hard World
Timing, Calendar and Clock, Audio, Video, Printer, Controls...

File System
Management, Filtering, File & Directory access, Viewers, ...

How can I call backticks without shell processing?

This is a bit tricky. Instead of writing

    @ok = `grep @opts '$search_string' @filenames`;

You have to do this:

    my @ok = ();
    if (open(GREP, "-|")) {
        while (<GREP>) {
            chomp;
            push(@ok, $_);
        }
        close GREP;
    } else {
        exec 'grep', @opts, $search_string, @filenames;
    }

Just as with system(), no shell escapes happen when you exec() a list.

Source: Perl FAQ: System Interaction
Copyright: Copyright (c) 1997 Tom Christiansen and Nathan Torkington.

Next: Why can't my script read from STDIN after I gave it EOF (^D on Unix, ^Z on MS-DOS)?

Previous: What's wrong with using backticks in a void context?

(Corrections, notes, and links courtesy of RocketAware.com)

[Overview Topics]

Up to: Current Process Control

Rapid-Links: Search | About | Comments | Submit Path: RocketAware > Perl > perlfaq8/How_can_I_call_backticks_without.htm