问题 Trying to execute it with all possible params, such as -d and full path etc.. No errors. When running another commands, all is ok, when running composer from CMD, all is ok too. Have tried exec, system, shell_exec etc.. What it could be? echo system('php composer.phar install'); 回答1: Try outputting the error stream as well: system('php composer.phar install 2>&1'); It might give you more of a hint as to what is going wrong. 回答2: Try this $path = 'path where, composer.phar and composer.json