Getting file extension in C

Question

How do you get a file extension (like .tiff) from a filename in C?

Thanks!

Answer 1

const char *get_filename_ext(const char *filename) {     const char *dot = strrchr(filename, '.');     if(!dot || dot == filename) return "";     return dot + 1; }  printf("%s\n", get_filename_ext("test.tiff")); printf("%s\n", get_filename_ext("test.blah.tiff")); printf("%s\n", get_filename_ext("test.")); printf("%s\n", get_filename_ext("test")); printf("%s\n", get_filename_ext("...")); 

Answer 2

Find the last dot with strrchr, then advance 1 char

#include <stdio.h> /* printf */ #include <string.h> /* strrchr */  ext = strrchr(filename, '.'); if (!ext) {     /* no extension */ } else {     printf("extension is %s\n", ext + 1); } 

Answer 3

You can use the strrchr function, which searches for the last occurrence of a character in a string, to find the final dot. From there, you can read off the rest of the string as the extension.