urlencode

#!/bin/sh

######################################################################
#
# URLENCODE - URL Encoder on the Basis of RFC 3986
#
# Usage   : urlencode [-r|--raw] <file> ...
# Args    : <file> ...... Text file for URL encoding
# Options : -r ...... RAW MODE : when this option is set, all of " " are
#                     replaced with "%20" instead of "+".
#           --raw ... same as the "-r" option
# Environs: LINE_BUFFERED
#             =yes ........ Line-buffered mode if possible
#             =forcible ... Line-buffered mode or exit if impossible
#
#
# Written by Shell-Shoccar Japan (@shellshoccarjpn) on 2022-02-08
#
# This is a public-domain software (CC0). It means that all of the
# people can use this for any purposes with no restrictions at all.
# By the way, We are fed up with the side effects which are brought
# about by the major licenses.
#
# The latest version is distributed at the following page.
# https://github.com/ShellShoccar-jpn/misc-tools
#
######################################################################


######################################################################
# Initial Configuration
######################################################################

# === Initialize shell environment ===================================
set -u
umask 0022
export LC_ALL=C
export PATH="$(command -p getconf PATH 2>/dev/null)${PATH+:}${PATH-}"
case $PATH in :*) PATH=${PATH#?};; esac
export UNIX_STD=2003  # to make HP-UX conform to POSIX

# === Define the functions for printing usage ========================
print_usage_and_exit() {
  cat <<-USAGE 1>&2
	Usage   : ${0##*/} [-r|--raw] <file> ...
	Args    : <file> ...... Text file for URL encoding
	Options : -r, --raw ... RAW MODE :
	                        " " will not be converted into "+" but "%20"
	Environs: LINE_BUFFERED
	            =yes ........ Line-buffered mode if possible
	            =forcible ... Line-buffered mode or exit if impossible
	Version : 2022-02-08 19:51:45 JST
	          (POSIX Bourne Shell/POSIX commands)
	USAGE
  exit 1
}


######################################################################
# Parse Options
######################################################################

# === Print help message if required =================================
case "${1:-}" in
  --help|--version|-h) print_usage_and_exit;;
esac

# === Other options ==================================================
instead_of_spc='+';
case $# in [!0]*)
  for arg in ${1+"$@"}; do
    case "$arg" in
      -r|--raw) instead_of_spc='%20'; shift;break;;
      --)                             shift;break;;
      *)        :                                ;;
    esac
  done
  ;;
esac


######################################################################
# Switch to the line-buffered mode if required
######################################################################
awkfl=''
case "${LINE_BUFFERED:-}" in
             [Ff][Oo][Rr][Cc][EeIi]*|2) lbm=2;;
  [Tt][Rr][Uu][Ee]|[Yy][Ee][Ss]|[Yy]|1) lbm=1;;
                                     *) lbm=0;;
esac
case $lbm in [!0]*)
  s=$(awk -W interactive 'BEGIN{}' 2>&1)
  case "$?$s" in
  '0') alias awk='awk -W interactive';;
    *) awkfl='system("");'           ;;
  esac
;; esac


######################################################################
# Main
######################################################################

(cat ${1+"$@"}; echo '')                                         |
awk '                                                            #
BEGIN {                                                          #
  # --- prepare                                                  #
  OFS = "";                                                      #
  ORS = "";                                                      #
  # --- prepare encoding                                         #
  for(i= 0;i<256;i++){c2p[sprintf("%c",i)]=sprintf("%%%02X",i);} #
  c2p[" "]="'"$instead_of_spc"'";                                #
  for(i=48;i< 58;i++){c2p[sprintf("%c",i)]=sprintf("%c",i);    } #
  for(i=65;i< 91;i++){c2p[sprintf("%c",i)]=sprintf("%c",i);    } #
  for(i=97;i<123;i++){c2p[sprintf("%c",i)]=sprintf("%c",i);    } #
  c2p["-"]="-"; c2p["."]="."; c2p["_"]="_"; c2p["~"]="~";        #
  # --- encode                                                   #
  while (getline line) {                                         #
    for (i=1; i<=length(line); i++) {                            #
      print c2p[substr(line,i,1)];                               #
    }                                                            #
    print "\n";'"$awkfl"'                                        #
  }                                                              #
}'                                                               |
awk '                                                            #
BEGIN{                                                           #
  ORS="";                                                        #
  OFS="";                                                        #
  getline line;                                                  #
  print line;                                                    #
  while (getline line) {                                         #
    print "\n",line;'"$awkfl"'                                   #
  }                                                              #
}                                                                #
'