PHP Tutorials - Herong's Tutorial Examples - v5.17, by Herong Yang
`command` - Backtick Operator
This section provides a tutorial example on how to use the shell_exec() function and the backtick operator `command` to invoke an external program. The program's standard output, stdout, is returned as the result of the operator.
The simplest option to execute a program on the operating system from a PHP script is probably to use the Backtick Operator `command`, which supports the following features:
Here are some examples of using the Backtick Operator `command` and shell_exec() function:
herong$ php -a Interactive shell php > print(`whoami`); herong php > $now = `date`; php > print($now); Sun Mar 3 08:43:56 CST 2020 php > print(shell_exec('whoami')); herong php > $now = shell_exec('date'); php > print($now); Sun Mar 3 08:43:56 CST 2020 php > $out = `sort`; Apple Orange Banana <Ctrl>-D php > echo $out; Apple Banana Orange
Note that is to end the standard input, stdin, stream.
Table of Contents
Introduction and Installation of PHP
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
►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
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
Managing PHP Engine and Modules on macOS