/in/ex1.c: In function 'main':
/in/ex1.c:13:57: error: conversion to 'char' from 'int' may alter its value [-Werror=conversion]
    if (fileName[i - 1][j] <= 'Z') fileName[i - 1][j] += ' ';
                                                         ^~~
/in/ex1.c:15:50: error: comparison of unsigned expression >= 0 is always true [-Werror=type-limits]
   for (size_t j = strlen(fileName[i - 1]) - 1; j >= 0; j--) {
                                                  ^~
cc1: all warnings being treated as errors