Improved main.c and syntax for the sake of the future children of the world

Improved main.c and syntax for the sake of the future children of the world
Removed division from get_stdin, and made it fail properly on failed allocation
Fixed the retard brain #include syntax/c.h shit (god I hope I didn't break highlightlighting I'm not - I checked and it outputs the same under the last commit, it's probably fine anon'll fix it what a cuck)
Much better input handling, properly using perror and handling multible files even under a noexist condition, probably fixed a seggy on noexist condition