args)Command line flag parser for Murex shell scripting
One of the nuisances of shell scripts is handling flags. More often than not your script will be littered with $1 still variables and not handle flags shifting in placement amongst a group of parameters. args aims to fix that by providing a common tool for parsing flags.
args takes a name of a variable to assign the result of the parsed parameters as well as a JSON structure containing the result. It also returns a non-zero exit number if there is an error when parsing.
args var-name { json-block } -> <stdout>#!/usr/bin/env murex
# First we define what parameters to accept:
# Pass the `args` function a JSON string (because JSON objects share the same braces as murex block, you can enter JSON
# directly as unescaped values as parameters in murex).
#
# --str: str == string data type
# --num: num == numeric data type
# --bool: bool == flag used == true, missing == false
# -b: --bool == alias of --bool flag
args args %{
AllowAdditional: true
Flags: {
--str: str
--num: num
--bool: bool
-b: --bool
}
}
catch {
# Lets check for errors in the command line parameters. If they exist then
# print the error and then exit.
err $args.error
exit 1
}
out "The structure of \$args is: ${$args->pretty}\n\n"
# Some example usage:
# -------------------
!if { $(args.Flags.--bool) } {
out "Flag `--bool` was not set."
}
# `<!null>` redirects the STDERR to a named pipe. In this instance it's the 'null' pipe so equivalent to 2>/dev/null
# thus we are just suppressing any error messages.
try <!null> {
$(args.Flags.--str) -> set fStr
$(args.Flags.--num) -> set fNum
out "Defined Flags:"
out " --str == $(fStr)"
out " --num == $(fNum)"
}
catch {
err "Missing `--str` and/or `--num` flags."
}
$args[Additional] -> foreach flag {
out "Additional argument (ie not assigned to a flag): `$(flag)`."
}This document was generated from builtins/core/management/shell_doc.yaml.
This site's content is rebuilt automatically from murex's source code after each merge to the master branch. Downloadable murex binaries are also built with the website.
Last built on Sat Nov 23 00:50:15 UTC 2024 against commit 69c17da69c17da3bd9db98ca508f6a03a402f074ee24cec.
Current version is 6.4.0375 (develop) which has been verified against tests cases.