For interactive use like these examples I think this is terrible advice. cat is very helpful because it fits into pipelines like every other command. For examp

For interactive use like these examples I think this is terrible advice. cat is very helpful because it fits into pipelines like every other command. For example: Take a look at the start of a file: head file Filter for things: head file | grep ... Reformat, remove unwanted stuff, etc.: head file | grep ... | sed ... Do things or dry run echo based on each line: head file | grep ... | sed ... | while read a; do ...; done It all looks good so we change head to cat to run it on the whole file: cat file | grep ... | sed ... | while read a; do... ; done Yes you can technically change "head file |" to "< file" but why bother? That's changes in two places and navigating between them instead of just <alt-d> cat. Same is true for other workflows. E.g. if you start with one of these supposedly better commands like "wc -l < file" (why isn't that just "wc -l file"?): wc -l < file Oh wait, we don't want every line, just ones matching a pattern. We could change it to wc -l <(grep ... file) or grep -c ... file which are both more work than just adding to an existing cat-based pipeline, where we just replace cat with "grep ...": grep ... file | wc -l If we need to also match another pattern or whatever this pipeline approach is better then too.