Shell_exec() returning null on "ls"

Asked
Active3 hr before
Viewed126 times

7 Answers

returning
90%

Meta Stack Overflow , Stack Overflow help chat , Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers , Stack Overflow Public questions & answers

Add 2>&1 to the end of your shell command to have STDERR returned as well as STDOUT.

$output = shell_exec("ls /root/files/saves 2>&1");
88%

The command that will be executed. ,exec() - Execute an external program,shell_exec — Execute command via shell and return the complete output as a string, A string containing the output from the executed command, false if the pipe cannot be established or null if an error occurs or the command produces no output.

load more v
72%

shell_exec — Execute command via shell and return the complete output as a string,Execute command via shell and return the complete output as a string, This function can return NULL both when an error occurs or the program produces no output. It is not possible to detect execution failures using this function. exec() should be used when access to the program exit code is required. , The output from the executed command or NULL if an error occurred or the command produces no output.

load more v
65%

The exec() function is an inbuilt function in PHP which is used to execute an external program and returns the last line of the output. It also returns NULL if no command run properly.,The shell_exec() function is an inbuilt function in PHP which is used to execute the commands via shell and return the complete output as a string. The shell_exec is an alias for the backtick operator, for those used to *nix. If the command fails return NULL and the values are not reliable for error checking.,Return Value: This function returns the executed command, be sure to set and use the output parameter.,Parameters: This function accepts single parameter $cmd which is used to hold the command that will be executed.

Syntax:

string shell_exec($cmd)

Output:

gfg.php
index.html
geeks.php

Syntax:

string exec($command, $output, $return_var)

Output:

geeks.php
load more v
75%

The exec() function is an inbuilt function in PHP which is used to execute an external program and returns the last line of the output. It also returns NULL if no command run properly.,The shell_exec() function is an inbuilt function in PHP which is used to execute the commands via shell and return the complete output as a string. The shell_exec is an alias for the backtick operator, for those used to *nix. If the command fails return NULL and the values are not reliable for error checking.,Return Value: This function returns the executed command, be sure to set and use the output parameter.,$output: This parameter is used to specify the array which will be filled with every line of output from the command.

Syntax:

string shell_exec($cmd)
load more v
40%

If an error occurred or no output is received, NULL will be returned,This tutorial explains how to use the shell_exec function in PHP in order to execute code via the shell and return the output as a string.,$command is a string containing the shell commands to run These commands will be determined your system environment and what software you have installed If an error occurred or no output is received, NULL will be returned ,This can be achieved by using the shell_exec function to execute commands on the system’s shell hosting your PHP code and return the result as a string to PHP.

shell_exec Syntax

shell_exec($command)
load more v
22%

Add 2>&1 to the end of your shell command to return STDERR as well as STDOUT .,Powershell script does not run through scheduled tasks - windows,So, I have this code, and I'm just trying to make a save list in another directory, where the php script is in the xampp folder, and it saves the path /root/files/saves :,In addition, if a user working with PHP does not have sufficient permissions to view the output in /root/ , then the above code will return a Permission denied error message.

So, I have this code, and I'm just trying to make a save list in another directory, where the php script is in the xampp folder, and it saves the path /root/files/saves :

 <html>

 <body> <?php $output = shell_exec('ls /root/files/saves'); echo "<pre>$output</pre>"; ?> </body>

 </html>
load more v

Other "returning-undefined" queries related to "Shell_exec() returning null on "ls""