Python as a shell replacement

Right, error handling is not easy in shell either. There are a number of things you can do but nothing is bullet proof, agreed. As a start, every single script of mine starts with set -e. I also use a lot of: "do_the_work_func || die ...", "while do_work; do..." etc. (pro tip: you generally don't need ret=$?)

BTW C has similar error handling behaviors, most likely not a coincidence.

I repeat: any shell program longer than a few thousands lines or with some serious data structures is probably a mistake. This being out of the way, let me try to rephrase and clarify what I meant earlier:

1. Python-as-a-shell adds extra code and significant overhead; you can't start prototyping by just throwing your .bash_history into a file anymore.
2. Python has a built-in and pretty good exception system that you generally don't even have to think about.

So why did the migration overhead I paid in 1. didn't magically give me 2. for free? Why do I have to think so much about error handling when I use the subprocess module? In _short_ shell scripts good error handling is the only thing I was missing! So where did my migration money go?

The Python people are very smart, so I guess there must be good technical reasons for that, yet these excuses still don't make Python a desirable replacement for short shell scripts (unless you absolutely need to support Windows). Actually, I'm worried these justifications may not be Python specific and may preclude _any_ general purpose language as a shell replacement...

Insightful interview with Steve Bourne: https://www.arnnet.com.au/article/279011/a-z_programming_...

set -e
f() {
    false
    echo "continued"
}
f || echo "failed"

continued

#!/bin/sh
# vim:set syntax=make:set ft=make:

MAKEFILE_START_LINE=$(\
  grep -nre makefile_starts_here "$0" \
  | tail -n 1 \
  | awk -F: '{print $1}')

TMP=$(mktemp)
tail -n+${MAKEFILE_START_LINE} "$0" > "${TMP}"

make -f "${TMP}"
SUCCESS=$?

rm -f "$TMP"
exit "$SUCCESS"

makefile_starts_here:
	command-1
	command-2
	command-3