popen() - Execute External Programs

This section provides a tutorial example on how to the popen() function to invoke an external program. The program's standard output, stdout, or input, stdin, is mapped to a file handle to reading or writing.

If you want to execute a program on the operating system and write to the standard input, stdin, or read the standard output, stdout, from the program, you can use the popen() function:

$fh = popen(string $command, string $mode);
...
pclose($fh);

Here is an example of using the popen() function to execute an external program, with stdout mapped to a file handle:

herong$ more popen-for-output.php
<?php
$fh = popen("sort", "w");
fwrite($fh,"Apple\n");
fwrite($fh,"Orange\n");
fwrite($fh,"Banana\n");
fclose($fh);
?>

herong$ php popen-for-output.php
Apple
Banana
Orange

Here is another example of using the popen() function to execute an external program, with stdin mapped to a file handle:

herong$ more popen-for-input.php
<?php
$fh = popen("sort", "r");
$out = fread($fh, 2048);
fclose($fh);
echo $out;
?>

herong$ php popen-for-input.php
Apple
Orange
Banana
<Ctrl>-D

Apple
Banana
Orange
?>

Table of Contents

 About This Book

 Introduction and Installation of PHP

 PHP Script File Syntax

 PHP Data Types and Data Literals

 Variables, References, and Constants

 Expressions, Operations and Type Conversions

 Conditional Statements - "if" and "switch"

 Loop Statements - "while", "for", and "do ... while"

 Function Declaration, Arguments, and Return Values

 Arrays - Ordered Maps

Interface with Operating System

 $argv[] - Command Line Arguments

 Options to Execute External Programs

 `command` - Backtick Operator

 exec() - Execute External Programs

 system() - Execute External Programs

 passthru() - Execute External Programs

popen() - Execute External Programs

 proc_open() - Execute External Programs

 memory_get_usage() - Memory Usage Info

 set_time_limit() - max_execution_time

 Introduction of Class and Object

 Integrating PHP with Apache Web Server

 Retrieving Information from HTTP Requests

 Creating and Managing Sessions in PHP Scripts

 Sending and Receiving Cookies in PHP Scripts

 Controlling HTTP Response Header Lines in PHP Scripts

 Managing File Upload

 MySQL Server Connection and Access Functions

 Functions to Manage Directories, Files and Images

 SOAP Extension Function and Calling Web Services

 SOAP Server Functions and Examples

 Localization Overview of Web Applications

 Using Non-ASCII Characters in HTML Documents

 Using Non-ASCII Characters as PHP Script String Literals

 Receiving Non-ASCII Characters from Input Forms

 "mbstring" Extension and Non-ASCII Encoding Management

 Managing Non-ASCII Character Strings with MySQL Servers

 Parsing and Managing HTML Documents

 Configuring and Sending Out Emails

 Image and Picture Processing

 Managing ZIP Archive Files

 Managing PHP Engine and Modules on macOS

 Managing PHP Engine and Modules on CentOS

 Archived Tutorials

 References

 Full Version in PDF/EPUB