Use of command_exists() for full command strings is flawed

[Imran-imtiaz48]

The function command_exists() is used with full commands like 'php --version' and 'mysqldump --version' to check if PHP and mysqldump are available on the system. However, this approach is incorrect because exec() interprets the entire string, not just the base command name. For example, exec("php --version", $output, $result_code) will fail if php exists but the specific flag or syntax causes a problem, or if the shell cannot interpret it properly. A more robust and portable way to check command availability would be to use only the binary name with something like which php or command -v php, not include arguments like --version. This bug can falsely signal that required commands are missing when they're not, leading to incorrect termination of the script.

[llagerlof]

I agree with you, but I’ve already verified that both php and mysqldump support the --version option, and I only use it with these two commands without any additional arguments.

I can’t use command since it doesn’t work in Windows CMD.

If you have a more robust and cross-platform solution, feel free to open a PR.

Thank you!