replace string in a text file

[Anon]

Hi. Can somebody help me with this:
I have a text file. In this file, I need to find certain string, let's say "xxxxx", and replace it with other string, let's say "yyyyy". How can I do it?
Thank you.

[amcgrath]

ummm, str_replace() should work for you... (note the catchy, obvious function name😉