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This article mainly introduces the relevant knowledge of "what is the common command execution function of PHP". The editor shows you the operation process through an actual case, and the operation method is simple, fast and practical. I hope this article "what is the common command execution function of PHP" can help you solve the problem.

PHP command execution functions are often used in conjunction with code execution vulnerabilities to launch attacks by using command execution functions to execute operating system commands, and then simply share a few commonly used PHP command execution functions

System ()

The system () function can execute the system command and output the result of the command execution directly to the interface. When you use it, you can directly pass in the command to be executed in the parameters.

System ('ls')

Exec ()

The exec () function can execute system commands, but it does not output the results directly, but saves the results to an array

Exec ('ls', $result)

Parameter 1: string type, system command to be executed

Parameter 2: array type, saving the execution results of system commands

Print_r ($result); / / output the execution result

Shell_exec ()

The shell_exec () function can execute system commands, but it does not directly output the results of execution. Instead, it returns a variable of string type to store the results of system commands, passing the system commands that need to be executed in the parameters.

Echo shell_exec ('ls')

Passthru ()

The passthru () function can execute the system command and output the execution result to the page. Unlike the system () function, it supports binary data and is more used for files, pictures and other operations. When in use, it can directly pass the system command of the string type in the parameter.

Passthru ('ls')

Popen ()

The popen () function can execute the system command, but does not output the execution result. Instead, it returns a variable of resource type to store the execution result of the system command. It needs to cooperate with the fread () function to read the execution result of the command.

$result = popen ('ls',' r')

Parameter 1: string type, command to be executed

Parameter 2: string type, pattern

Return value: resource type, result of command execution

Echo fread ($result, 100)

Parameter 1: resource type, file pointer to be read

Parameter 2:int type, read n bytes

Return value: string type, contents of the file read

Echo fread (popen ('ls','r'), 100)

Back quotation mark ``

The backquote can execute the system command, but it does not output the result, but returns a variable of string type, which is used to store the execution result of the system command, which can be used alone or in conjunction with other command execution functions to bypass the filtering conditions in the parameter.

Echo `ls`

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