File: dog.sh
   1 #!/bin/sh
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright (c) 2026 pacman64
   6 #
   7 # Permission is hereby granted, free of charge, to any person obtaining a copy
   8 # of this software and associated documentation files (the "Software"), to deal
   9 # in the Software without restriction, including without limitation the rights
  10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 # copies of the Software, and to permit persons to whom the Software is
  12 # furnished to do so, subject to the following conditions:
  13 #
  14 # The above copyright notice and this permission notice shall be included in
  15 # all copies or substantial portions of the Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23 # SOFTWARE.
  24 
  25 
  26 # dog [options...] [paths/URIs...]
  27 #
  28 # Dog fetches data from the named sources given to it, whether these are
  29 # filenames or URIs. Single dashes stand for standard input, and can't be
  30 # used more than once. When no names are given, stdin is read by default.
  31 
  32 
  33 # fail quits the script right after showing the message given, using the
  34 # exit code given as its 2nd arg
  35 fail() {
  36     printf "%s\n" "$1" >&2
  37     exit "${2:-1}"
  38 }
  39 
  40 # when no args are given, just show the help message and quit
  41 if [ $# -eq 0 ]; then
  42     awk '/^# +dog /, /^$/ { gsub(/^# ?/, ""); print }' "$0" >&2
  43     exit 1
  44 fi
  45 
  46 case "$1" in
  47     -h|--h|-help|--help)
  48         awk '/^# +dog /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  49         exit 0
  50     ;;
  51 esac
  52 
  53 [ "$1" = '--' ] && shift
  54 
  55 # ensure single dashes aren't used multiple times
  56 dashes=0
  57 for name in "$@"; do
  58     if [ "${name}" = "-" ]; then
  59         if [ "$dashes" -gt 0 ]; then
  60             fail "can't use stdin (single-dash) more than once" 1
  61         fi
  62         dashes=1
  63     fi
  64 done
  65 
  66 for name in "$@"; do
  67     case "${name}" in
  68         # handle a dash by reading from stdin
  69         -) cat || exit $?;;
  70 
  71         # handle URIs
  72         dict://*|file://*|ftp://*|ftps://*|gopher://*|gophers://*|http://*\
  73         |https://*|rtmp://*|rtsp://*|scp://*|sftp://*|telnet://*|tftp://*)
  74             curl -s -L "${name}" || fail "failed to fetch URI ${name}" $?;;
  75 
  76         # handle data-URIs
  77         data:,) continue;;
  78         data:*) {
  79             printf "%s" "${name}" | sed -E 's-^data:.{0,50};base64,--' |
  80                 base64 -d
  81         } || fail "failed to decode data-URI ${name}" $?;;
  82 
  83         # handle files and bytes-mode data-URIs
  84         *) cat "${name}" || fail "failed to open file ${name}" $?;;
  85     esac
  86 done