I need to write a little program that reads from file_1 two values per line, and then reads from file_2 if the first value of file_1 is there and replace in file_2 (or write in another file) the new value.
Originally posted by Aiglee Castillo: ...I don't need actual code, but the functions or path I should take...
Is there a specific part of this process that you're questioning?
If not, then here's my general advice: Describe your process in English before starting to code, breaking it down into detailed steps. (Something like: Read this value and store it here. Compare this variable to that variable. If this specific condition is true, then...) Once you have the process (logic) defined, then you can start translating it into code.
"We're kind of on the level of crossword puzzle writers... And no one ever goes to them and gives them an award." ~Joe Strummer sscce.org