File Test Operators

This section provides a tutorial example on using file test operators to return information about a file or a directory in the file system. For example, -e tests if a file exists or not.

Perl offers a number of unary operators to return statistics of a file or a directory in the file system. Some commonly used ones are:

Here is a tutorial example script of using file test operators:

#- FileTestOperators.pl
#- Copyright (c) 2002 by Dr. Herong Yang, http://www.herongyang.com/
#
   print -e "/windows", "\n";             # 1
   print -d "/windows", "\n";             # 1
   print -f "/windows", "\n";             #
   print -e "/windows/test", "\n";        #
   print -e "/windows/system.ini", "\n";  # 1
   print -d "/windows/system.ini", "\n";  #
   print -f "/windows/system.ini", "\n";  # 1
   print -s "/windows/system.ini", "\n";  # 231
   print -z "/windows/system.ini", "\n";  #
   print -T "/windows/system.ini", "\n";  # 1
   print -B "/windows/system.ini", "\n";  #

If you run it on a Windows system, you will get something similar to this:

1
1


1

1
231

1

Table of Contents

 About This Book

 Perl on Linux Systems

 ActivePerl on Windows Systems

 Data Types: Values and Variables

 Expressions, Operations and Simple Statements

 User Defined Subroutines

 Perl Built-in Debugger

 Name Spaces and Perl Module Files

 Symbolic (or Soft) References

 Hard References - Addresses of Memory Objects

 Objects (or References) and Classes (or Packages)

 Typeglob and Importing Identifiers from Other Packages

 String Built-in Functions and Performance

 File Handles and Data Input/Output

 Open Files in Binary Mode

 Open Directories and Read File Names

File System Functions and Operations

 Built-in Functions to Work with the File System

File Test Operators

 stat() - Returns File Statistics

 Converting Perl Script to Executable Binary

 Using DBM Database Files

 Using MySQL Database Server

 Socket Communication Over the Internet

 XML::Simple Module - XML Parser and Generator

 XML Communication Model

 SOAP::Lite - SOAP Server-Client Communication Module

 Perl Programs as IIS Server CGI Scripts

 CGI (Common Gateway Interface)

 XML-RPC - Remote Procedure Call with XML and HTTP

 RPC::XML - Perl Implementation of XML-RPC

 Integrating Perl with Apache Web Server

 CGI.pm Module for Building Web Pages

 LWP::UserAgent and Web Site Testing

 References

 PDF Printing Version