Matching a function name

[Omegavirus]

I need a regex that matches all instances of a particular PHP function name in given a piece of code.The regex should match \[code\]foo\[/code\] in:\[code\]foo("qwe");function foo($param);return foo();\[/code\]An not match \[code\]foo\[/code\] in:\[code\]my_foo("qwe");foo_bar();"some foo string"\[/code\]