mirror of
https://github.com/notwa/rc
synced 2024-11-12 16:09:04 -08:00
95 lines
3.3 KiB
Bash
95 lines
3.3 KiB
Bash
#!/usr/bin/env sh
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# YES_ZSH YES_BASH YES_DASH YES_ASH
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permit() { ### @- conditionally set executable permissions on each of its arguments.
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### flags:
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### * `-a` -- automatic: skip any files whose contents do not begin with
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### with one of several signatures. this does not affect directories.
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### * `-A` -- turn off automatic mode. (default)
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### * `-e` -- everything: consider both regular files and directories. (default)
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### * `-f` -- files: skip any arguments that are not regular files.
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### * `-d` -- directories: skip any arguments that are not directories.
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###
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### the `-e`, `-f`, and `-d` flags all override one another, and any of them
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### can be combined with `-a`. arguments that are neither regular files nor
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### directories (such as symlinks) are always skipped. arguments that are
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### already executable by the current user are skipped. arguments that do
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### not appear to refer to an existing file are passed through to chmod.
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### directories are never recursed.
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unset __permit_4 __permit_a __permit_f __permit_h __permit_m __permit_n __permit_x || return
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__permit_h="[-a | -A] [-e | -f | -d] [--] {files...}"
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if [ $# = 0 ]; then
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printf >&2 'usage: permit %s\n' "$__permit_h"
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return 64;
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fi
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__permit_m=e # everything
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__permit_a=0 # automatic
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__permit_n=$#
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while [ $((__permit_n-=1)) -ge 0 ]; do
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__permit_f="$1"
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case "$__permit_f" in
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(/\?|-h|-help|--help)
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printf 'usage: permit %s\n' "$__permit_h"
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return 0;;
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(--)
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shift
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while [ $((__permit_n-=1)) -ge 0 ]; do
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set -- "$@" "$1"
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shift
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done
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break;;
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(-*)
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shift
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case "${__permit_f#-}" in
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(a) __permit_a=1;; # automatic (on)
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(A) __permit_a=0;; # automatic (off)
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(e) __permit_m=e;; # everything
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(f) __permit_m=f;; # files only
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(d) __permit_m=d;; # directories only
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(?|-*)
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printf >&2 'permit: %s\n' "unknown flag: $__permit_f"
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return 64;;
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(*)
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set -- "${__permit_f%"${__permit_f#-?}"}" "-${__permit_f#-?}" "$@"
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: $((__permit_n+=2))
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continue;;
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esac;;
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(*)
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shift
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set -- "$@" "$__permit_f";;
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esac
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done
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if [ $# = 0 ]; then
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printf >&2 'usage: permit %s\n' "$__permit_h"
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return 64;
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fi
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__permit_x=
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for __permit_f; do
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[ -n "$__permit_x" ] || { __permit_x=0; set --; }
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if [ -x "$__permit_f" ]; then
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: # pass
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elif ! [ -e "$__permit_f" ]; then
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set -- "$@" "$__permit_f"
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elif [ "$__permit_a" = 1 ] && ! [ -d "$__permit_f" ]; then
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__permit_4="$(exec hexdump -ve '1 1 "%02X"' -n4 -- "$__permit_f")" || __permit=$?
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case "$__permit_4" in (7F454C46) false;; (2321*) false;; (4D5A*) false;;
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esac || set -- "$@" "$__permit_f" # runs when a case matches
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elif [ "-$__permit_m" "$__permit_f" ]; then
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set -- "$@" "$__permit_f"
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fi
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done
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[ "$#" = 0 ] || chmod +x -- "$@" || __permit_x=$?
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return "$__permit_x"
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}
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[ -n "${preload+-}" ] || permit "$@"
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