File: dog.sh
   1 #!/bin/sh
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright © 2020-2025 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
  34 # exit code given as its 2nd arg
  35 fail() {
  36     printf "\e[31m%s\e[0m\n" "$1" > /dev/stderr
  37     exit "${2:-1}"
  38 }
  39 
  40 # when no args are given, just show the help message and quit
  41 if [ $# -eq 0 ]; then
  42     exit $?
  43 fi
  44 
  45 case "$1" in
  46     -h|--h|-help|--help)
  47         awk '/^# +dog /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  48         exit 0
  49     ;;
  50 esac
  51 
  52 # ensure single dashes aren't used multiple times
  53 dashes=0
  54 for name in "$@"; do
  55     if [ "${name}" = "-" ]; then
  56         if [ "$dashes" -gt 0 ]; then
  57             fail "can't use stdin (single-dash) more than once" 1
  58         fi
  59         dashes=1
  60     fi
  61 done
  62 
  63 for name in "$@"; do
  64     case "${name}" in
  65         # handle a dash by reading from stdin
  66         -) cat || exit $?;;
  67 
  68         # handle URIs
  69         dict://*|file://*|ftp://*|ftps://*|gopher://*|gophers://*|\
  70         http://*|https://*|rtmp://*|rtsp://*|scp://*|sftp://*|\
  71         smb://*|smbs://*|telnet://*|tftp://*)
  72             curl -s -L "${name}" || fail "failed to fetch URI ${name}" $?;;
  73 
  74         # handle data-URIs
  75         data:*) {
  76             printf "%s" "${name}" | sed -E 's-^data:.{0,50};base64,--' |
  77                 base64 -d
  78         } || fail "failed to decode data-URI ${name}" $?;;
  79 
  80         # handle files and bytes-mode data-URIs
  81         *) cat "${name}" || fail "failed to open file ${name}" $?;;
  82     esac
  83 done