Question

Say I have to remove the last occurrence of a string from another string. How would I go about it?

To elaborate, I have a file name in a c string (gchar* or char* )

C:\SomeDir\SomeFolder\MyFile.pdf

and I want to remove the extension .pdf , and change it to something else, e.g .txt or .png . What is the least troublesome yet efficient , convenient and cross-platform way to do it? Thanks.

note: I know this is an extremely simple thing to do in C++ but for this project , I absolutely MUST use C and no other language. (academic requirement)

note 2: Although you can suggest other third-party library , I currently only have access to the C standard library and the GLib.

note 3: I have searched for similar questions with the “C” tag, but can’t seem to find any.

Answer 1

char fil[] = "C:\\SomeDir\\SomeFolder\\MyFile.pdf";
char fil2[1000];
char extension[] = ".tmp";

// search for . and add new extension
sprintf(fil2, "%s%s", strtok(fil, "."), extension);
printf("%s\n", fil2);