How to debug an execution line

Question

I want do debug this line:

exec("mysqldump --add-drop-table -h 127.0.0.1 -u$db_user -p$db_pass $db_name > $db_name.sql");

... because this is not working. Is it possible? I want to create a script that get all content from several databases and this line is not working, it creates a .sql file but does not save any info. there.

Answer 1

Add a space after the -u. reference link

exec("mysqldump --add-drop-table -h 127.0.0.1 -u $db_user -p$db_pass $db_name > $db_name.sql");