Finding call-time pass by references in PHP.
While trying to move an older code base to a newer system and thus a newer version of PHP (5.3 -> 5.5), I knew that some of the code would need to be changed to avoid using some removed features. Specifically, I mean call-time pass by references. For those who don’t know, this is kind of a weird feature of earlier versions of PHP that allows one to call a function and pass any of the arguments by reference rather than the usual call by value if the caller prepends an argument variable with the “reference to” operator &.
So, to illustrate, normally this code won’t have side effects because of call by value:
1 2 3 4 | function do_me( $var ) { $var = "I'm doing it: " . $var; echo $var; } |
However there will be side effects if the caller chooses pass by reference:
1 2 | $text = "happily"; do_me( &$text ); |
I thought a regex might be in order to find these guys and fix them:
1 | ag -r -G '\.(php|module|inc|page|view)$' '^(?:(?!function).)*\([^&]*&[^&#][[:alpha:]$_].*\)' |
but it was a naive idea, and this regex devolved (heh) to its current form before I realized I could just use the built-in linter to find the problem spots.
1 | find . | grep -Fv '/\.svn' | grep -E '\.(php|module|inc|page|view)$' | xargs -n 1 php -l |
HTH