mirror of
https://github.com/notwa/rc
synced 2024-11-05 08:29:02 -08:00
67 lines
1.6 KiB
Bash
Executable file
67 lines
1.6 KiB
Bash
Executable file
#!/usr/bin/env sh
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# YES_ZSH
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# YES_BASH
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# YES_DASH
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# YES_ASH
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argc() { ### @- validate the number of arguments in a function.
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### ```sh
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### # usage: myfunc() { argc $# -(eq|le|ge) [0-9] "$0" || return; }
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###
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### myfunc() {
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### # use one of the following:
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### argc $# -eq N "$0" || return
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### argc $# -le N "$0" || return
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### argc $# -ge N "$0" || return
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### # where N is an integer between 0 and 9.
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### }
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### ```
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local usage='usage: myfunc() { %s $# -(eq|le|ge) [0-9] "$0" || return; }\n'
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# note that $zero can be empty, but must be set.
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if [ $# -ne 4 ] || [ -z "$1" ] || [ -z "$2" ] || [ -z "$3" ]; then
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printf "$usage" argc >&2
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return 2
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fi
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local argc="$1"; shift
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local cond="$1"; shift
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local want="$1"; shift
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local zero="$1"; shift
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local many='' plural=''
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[ "$want" = 1 ] || plural='s'
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if [ "$argc" != "${argc%%[!0-9]*}" ]; then
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printf "$usage" argc >&2
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return 2
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fi
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case "$cond" in
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('-eq') many='exactly';;
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('-le') many='at most';;
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('-ge') many='at least';;
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(*)
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printf "$usage" argc >&2
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return 2;;
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esac
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case "$want" in
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([0-9]) :;; # no error, continue.
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(*)
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printf "$usage" argc >&2
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return 2;;
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esac
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if [ "$argc" "$cond" "$want" ] 2>/dev/null; then
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:
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else
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local err="expected $many $want argument$plural, got"
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printf '%s: %s %s\n' "$zero" "$err" "$argc" >&2
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return 1
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fi
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return 0
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}
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[ -n "${preload+-}" ] || argc "$@"
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