File: get.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 # get [options...] [filepaths/URIs/data-URIs...]
  27 #
  28 # Get data from the named source given, whether this is a filename, a URI,
  29 # or even a base64-encoded data-URI. Data-URIs are simply decoded into the
  30 # bytes they represent, no loading/fetching required.
  31 #
  32 # The only options show this help message, via any of `-h`, `--h`, `-help`,
  33 # or `--help`, without the quotes.
  34 
  35 
  36 # fail quits the script right after showing the message given, using the
  37 # exit code given as its 2nd arg
  38 fail() {
  39     printf "%s\n" "$1" > /dev/stderr
  40     exit "${2:-1}"
  41 }
  42 
  43 
  44 case "$1" in
  45     -h|--h|-help|--help)
  46         awk '/^# +get /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  47         exit 0
  48     ;;
  49 esac
  50 
  51 [ "$1" = '--' ] && shift
  52 
  53 dashes=0
  54 for name in "${@:--}"; do
  55     if [ "${name}" = "-" ]; then
  56         dashes="$((dashes + 1))"
  57     fi
  58 
  59     if [ "${dashes}" -gt 1 ]; then
  60         break
  61     fi
  62 done
  63 
  64 if [ "${dashes}" -gt 1 ] && [ ! -e '-' ]; then
  65     printf "can't use dash/stdin multiple times\n" >&2
  66     exit 1
  67 fi
  68 
  69 for name in "${@:--}"; do
  70     if [ -z "${name}" ]; then
  71         continue
  72     fi
  73 
  74     # if the argument given is an existing file, just use `cat`, even if the
  75     # name looks like a protocol presumably meant for `curl`
  76     if [ -e "${name}" ]; then
  77         cat "${name}" || fail "failed to read file '${name}'" $?
  78         continue
  79     fi
  80 
  81     case "${name}" in
  82         # handle the commonest kinds of URIs
  83         dict://*|ftps://*|gopher://*|gophers://*|http://*|https://*|rtmp://*|\
  84         rtsp://*|scp://*|sftp://*|smb://*|smbs://*|telnet://*|tftp://*)
  85             curl -s -L "${name}" || fail "failed to fetch URI '${name}'" $?
  86         ;;
  87 
  88         # handle data-URIs
  89         data:*)
  90             {
  91                 echo "${name}" | sed -E 's-^data:.{0,50};base64,--' | base64 -d
  92             } || fail "failed to decode data-URI '${name}'" $?
  93         ;;
  94 
  95         # handle files
  96         file://*)
  97             cat "$(echo "${name}" | sed 's-^file://--')" 2> /dev/null ||
  98                 fail "failed to open file '${name}'" $?
  99         ;;
 100 
 101         # handle standard input
 102         -)
 103             cat "${name}" 2> /dev/null ||
 104                 fail "failed to read from the standard input" $?
 105         ;;
 106 
 107         # file not found
 108         *)
 109             fail "no file named '${name}'" 1
 110         ;;
 111     esac
 112 done