即使它工作，Exec也返回false

Question

I want to backup a database so i'm using mysqldump through php to achieve this,in the following way:

exec("mysqldump -h $dbhost -u $dbuser -p'$dbpass' $d > $bkp_file", $output, $return);

I specified the output and return parameters to get a status of the command for the further verification. The command works,i get the sql file,populated, but the return variable have the value of 0.

Am i missing something?

Answer 1

An exit status of zero means success.

Any other value is used to indicate some kind of error. Check the documentation of the launched app for details.