What does exec return in php

In PHP, the exec() function returns the last line of the command execution result. This function is used to execute an external program. When the output parameter of the function is specified, the output will be filled with the return result. If there are already elements in the output parameter, the exec function will append it after the output.

The operating environment of this article: Windows 10 system, PHP version 7.1, Dell G3 computer.

What does exec return in php

exec() will return the last line of the specified command result by default. If the output parameter is specified, the output will be filled with the returned result; if there are already elements in the output parameter, exec() will append after output.

exec executes an external program

Description

exec(string $command, array &$output = ?, int &$return_var = ?): string

exec() executes the command specified by the command parameter.

Parameters

command The command to be executed.

output If the output parameter is provided, this array will be filled with the output of the command execution, with each line of output filling one element in the array. The data in the array does not contain trailing whitespace characters, such as \n characters. Please note that if the array already contains some elements, the exec() function will append the content to the end of the array. If you don't want to append at the end of the array, use the unset() function to reset the array before passing it to the exec() function.

return_var If both output and return_var parameters are provided, the return status after command execution will be written to this variable.

Return value

The last line of the command execution result. If you want to get the output of the command, make sure to use the output parameter.

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