bash - Why does ls give different output when piped

Question

Printing to terminal directly:

$ ls
a.out  avg.c  avg.h

Piping to cat

$ ls | cat
a.out
avg.c
avg.h

Why does ls give a different output based on destination?

Answer 1

ls automatically behaves like ls -1 when piped.

This is usually what you want when you are piping ls to awk or something like that, since it will treat the output of ls on a line-by-line basis.

To override this default behavior, you can use ls -C | cat.