Find - IfFound - IfNotFound in CodeIgniter

I want to carry out a simple set of functions that I can do easily in a text editor but I cant find how it can be done in CodeIgniter or PHP.

I would set out the functions in a text editor as follows;

PHP Code:

Open "C:\Folder1\File1.txt"
Find "abc"
IfNotFound
"Open "C:\Folder2\File.txt"
Find "abc"
EndIf
IfNotFound
"Open "C:\Folder3\File.txt"
Find "abc"
EndIf
IfNotFound
"Open "C:\Folder4\File.txt"
"say something"
ExitMacro
EndIf
IfFound
"Open "C:\Folder5\File.txt"
Find "def"
EndIf
IfNotFound
"Open "C:\Folder6\File.txt"
"say something different"
EndIf
IfFound
"Open "C:\Folder7\File.txt"
"say something else"
EndIf 


Does anybody know if the same set of functions can be done in CodeIgniter?

I know how to "fopen" in CodeIgniter but that is all.