ini

#!/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/>.

################################################################################
# Ini File functions ###########################################################
################################################################################

include string error_messages

ini_set_file () {
  declare -g __INI_FILE="${1:?$FUNCNAME: Missing argument}"
}

ini_get_file () {
  echo "$__INI_FILE"
}

ini_file_okay () {
  local FILE="${__INI_FILE:?$FUNCNAME: \$__INI_FILE not set}"

  if [[ -f "$FILE" ]] && [[ -r "$FILE" ]] ; then
    return 0
  elif ! [[ -e "$FILE" ]] ; then
    error_missing_file "$FILE"
    return 1
  elif [[ -d "$FILE" ]] ; then
    error_is_directory "$FILE"
    return 1
  elif ! [[ -r "$FILE" ]] ; then
    error_permission_denied "$FILE"
    return 1
  fi
}

ini_print_file () {
  ini_file_okay || return 1

  local S='[[:space:]]'  # space class
  local N='[^[:space:]]' # non space class
  local NP='[^[:print:]]' # non printable class

  # remove leading spaces
  # remove spaces aside of the equal sign (e.g. "variable = value" turns to "variable=value")
  # remove spaces in sections (e.g. "[  section ]" turns to "[section]")
  # remove all non printable characters
  # remove comments ("#" and ";") and empty lines
  sed -r "s/^$S+//g; s/^($N+)$S*=$S*/\1=/g; s/\[$S*($N+)$S*\]/[\1]/g; s/$NP//g" "$__INI_FILE" | grep -Eo '^[^#;].+'
}

ini_list_sections () {
  ini_file_okay || return 1
  ini_print_file | grep '^\[' | tr -d \[\]
}

ini_list_variables () {
  ini_file_okay || return 1
  local SECTION="${1:?$FUNCNAME: Missing argument}"

  ini_get_section "$SECTION" | sed 's/=.*//g'
}

ini_section_exists () {
  ini_file_okay || return 1
  local SECTION="${1:?$FUNCNAME: Missing argument}"

  ini_print_file | grep -qF "[$SECTION]"
}

ini_get_section () {
  ini_file_okay || return 1
  local SECTION="${1:?$FUNCNAME: Missing argument}"
  local REPLY SEC_OPEN=0

  ini_print_file | while read; do

    if [[ "${REPLY:0:1}" == "[" ]] ; then # is it a new section?
      if [[ "${REPLY}" == "[$SECTION]" ]] ; then # is it the wanted section?
        SEC_OPEN=1 # yes: section is now open!
        continue
      else
        SEC_OPEN=0 # no: section is closed
        continue
      fi
    fi

    [[ $SEC_OPEN == 1 ]] && echo "$REPLY"
  done
}

ini_get_variable () {
  ini_file_okay || return 1
  local SECTION="${1:?$FUNCNAME: Missing argument}"
  local VARIABLE="${2:?$FUNCNAME: Missing argument}"

  local VALUE=`ini_get_section "$SECTION" | grep -F "$VARIABLE="`
  unquote "${VALUE:$(( ${#VARIABLE} + 1 ))}"
}

ini_variable_exists () {
  ini_file_okay || return 1
  local SECTION="${1:?$FUNCNAME: Missing argument}"
  local VARIABLE="${2:?$FUNCNAME: Missing argument}"

  ini_list_variables "$SECTION" | grep -qF "$VARIABLE="
}

ini_remove_section () {
  ini_file_okay || return 1
  local SECTION="${1:?$FUNCNAME: Missing argument}"
  local REPLY SEC_OPEN=0

  ini_print_file | while read; do

    if [[ "${REPLY:0:1}" == "[" ]] ; then # is it a new section?
      if [[ "${REPLY}" == "[$SECTION]" ]] ; then # is it the wanted section?
        SEC_OPEN=1 # yes: section is now open!
      else
        SEC_OPEN=0 # no: section is closed
      fi
    fi

    [[ $SEC_OPEN == 0 ]] && echo "$REPLY"
  done
}