string

#!/bin/bash

# Copyright (C) 2015 Benjamin Abendroth
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

################################################################################
# String functions #############################################################
################################################################################

substr() {
  echo "${1:$2:$3}"
}

tolower() {
  echo "${1,,}"
}

toupper() {
  echo "${1^^}"
}

swapcase() {
  echo "${1~~}"
  # undocumented bash feature!
}

remove_colorcodes () {
  sed 's/\\\033[^a-zA-Z]*.//g'
}

valid_pathname () {
  echo "$@" | tr -sc '[:alnum:]-_,/' '.' | sed 's/\.$//; s/^\.//;'
}

get_extension() {
  echo "${1##*.}"
}

no_extension() {
  echo "${1%.*}"
}

unquote() {
  local STRING="${1:?$FUNCNAME: Missing argument}"
  local QUOTES="" I=0 CHAR="" ESCAPE=0

  for I in `seq 0 ${#STRING}`; do
    CHAR="${STRING:$I:1}"

    case "$QUOTES" in
    \") 
        if (( $ESCAPE == 1 )) ; then
          ESCAPE=0
          printf "\\$CHAR"
          continue
        fi

        case "$CHAR" in
        \\) ESCAPE=1 ;;
        \") QUOTES= ;;
         *) printf "$CHAR" ;;
        esac ;;
    \')
        case "$CHAR" in
        \') QUOTES= ;;
         *) printf "$CHAR" ;;
        esac ;;
     *)
        case "$CHAR" in
        \") QUOTES=\" ;;
        \') QUOTES=\' ;;
         *) printf "$CHAR" ;;
        esac ;;
    esac
  done
}
#' vim bug xD

#unquote () {
#  eval printf "$1"
#}
# faster solution, but insecure!