Bash code generator for command-line arguments • Hacker News Board

Re: Bash code generator for command-line arguments

#51

Post by matheusmoreira » Fri, Oct 02, 2020, 7:12 PM UTC

xandris wrote: post #42

bxparks wrote: post #28

Earlier quoted context omitted.

You mean like this? echo "message" 1>&2 Yes, that's probably a good idea, though I cannot recall this causing a problem for any script that I've written so far.

Wait, --help should print to stdout so that fancycommand --help | less works as expected. Otherwise, the help text will dump to the screen and less will erase it when it decides to redraw its empty buffer! Actual error messages should go to stderr so that I can redirect them to an error log or so I can suppress them if need be, or I could also be doing > /dev/stdout to silence normal output but I don't want errors to…

I agree. When a program is given the --help option, the usage information is the actual output.

Re: Bash code generator for command-line arguments

#52

Post by matheusmoreira » Fri, Oct 02, 2020, 7:17 PM UTC

bxparks wrote: post #28

matheusmoreira wrote: post #23

Earlier quoted context omitted.

This is nice! I suggest writing messages to standard error instead of standard output.

You mean like this? echo "message" 1>&2 Yes, that's probably a good idea, though I cannot recall this causing a problem for any script that I've written so far.

It allows users to easily separate messages intended for the user from output which can be consumed by other scripts.

  $ tens.sh --verbose 5
  10
  100
  1000
  10000
  100000
  Calculated 5 results

  $ tens.sh --verbose 5 > results
  Calculated 5 results

Re: Bash code generator for command-line arguments

#53

Post by lysium » Sun, Oct 11, 2020, 12:11 PM UTC

lou1306 wrote: post #14

lysium wrote: post #4

Earlier quoted context omitted.

I've tried that path with little success. Usually, arg parsing makes me try some other language (perl, python) but other things got complicated there, mostly running other processes, capturing their exit status, pipe-ing their output etc. In the end, it was easier to hammer onto bash. Also, there are great linters for bash scripts, so things work out.

> but other things got complicated there, mostly running other processes, capturing their exit status, pipe-ing their output Note that Python's subprocess module [0] has received many updates since v3.5, and now I find it relatively painless. Most of the times, subprocess.check_output() or subprocess.run() will do the trick. [0]: https://docs.python.org/3/library/subprocess.html

Thx, I’ll check it out again!

Re: Bash code generator for command-line arguments

#54

Post by lysium » Sun, Oct 11, 2020, 12:12 PM UTC

IggleSniggle wrote: post #9

lysium wrote: post #4

Earlier quoted context omitted.

I've tried that path with little success. Usually, arg parsing makes me try some other language (perl, python) but other things got complicated there, mostly running other processes, capturing their exit status, pipe-ing their output etc. In the end, it was easier to hammer onto bash. Also, there are great linters for bash scripts, so things work out.

tcl is designed for this situation

Thx, I’ll give it a shot!