Compilare: main.c: In function 'main': main.c:24:3: warning: ignoring return value of 'fgets', declared with attribute warn_unused_result [-Wunused-result] fgets(src, MAXN + 1, fin); ^~~~~~~~~~~~~~~~~~~~~~~~~ main.c:25:3: warning: ignoring return value of 'fgets', declared with attribute warn_unused_result [-Wunused-result] fgets(str, MAXN + 1, fin); ^~~~~~~~~~~~~~~~~~~~~~~~~