shell-ini-config

#!/bin/sh -efu
### This file is covered by the GNU General Public License,
### which should be included with libshell as the file LICENSE.
### All copyright information are listed in the COPYING.

if [ -z "${__included_shell_ini_config-}" ]; then
__included_shell_ini_config=1

shell_ini_config_comment='#'
shell_ini_config_prefix='	'

. shell-error
. shell-var

__ini_config_print()
{
	local p="$1"; shift
	printf '%s%s\n' "${p:+${shell_ini_config_prefix-}}" "$@"
}

### Usage: ini_config_get file section var
ini_config_get()
{
	local fn section var sect='' str eof='' n v
	fn="$1" section="$2" var="$3"

	if [ ! -e "$fn" ]; then
		message "No such file or directory: $fn"
		return 1
	fi

	while [ -z "$eof" ]; do
		read -r str || eof=1

		case "$str" in
			"["*"]")
				# Reset section variable on section change
				sect=
				[ "$str" != "[$section]" ] ||
					sect=1
				;;
			"$shell_ini_config_comment"*|'')
				;;
			*)
				if [ -n "$sect" ]; then
					shell_var_trim n "${str%%=*}"

					if [ "$n" = "$var" ]; then
						shell_var_trim v "${str#*=}"
						printf '%s\n' "$v"
						break
					fi
				fi
				;;
		esac
	done < "$fn"
}

# Usage: ini_config_is_set file section var
ini_config_is_set()
{
	local fn section var sect='' str eof='' n v
	fn="$1" section="$2" var="$3"

	if [ ! -e "$fn" ]; then
		message "No such file or directory: $fn"
		return 1
	fi

	while [ -z "$eof" ]; do
		read -r str || eof=1

		case "$str" in
			"["*"]")
				# Reset section variable on section change
				sect=
				[ "$str" != "[$section]" ] ||
					sect=1
				;;
			"$shell_ini_config_comment"*|'')
				;;
			*)
				if [ -n "$sect" ]; then
					shell_var_trim n "${str%%=*}"

					if [ "$n" = "$var" ]; then
						# Return success, since we found match.
						return 0
					fi
				fi
				;;
		esac
	done < "$fn"

	# We did not find match, so return failure.
	return 1
}

### Usage: ini_config_set file section var value
ini_config_set()
{
	local fn fn_tmp section var value sect='' don='' str tstr eof='' n v

	fn="$1" section="$2" var="$3" value="$4"

	if [ ! -e "$fn" ]; then
		message "No such file or directory: $fn"
		return 1
	fi

	fn_tmp="$(mktemp "$fn.XXXXXX")"

	while [ -z "$eof" ]; do
		IFS='' read -r str || eof=1

		shell_var_trim tstr "$str"

		case "$tstr" in
			"[$section]")
				sect=2
				printf '%s\n' "$tstr"
				;;
			"["*"]")
				if [ "$sect" = 2 ] && [ -z "$don" ]; then
					__ini_config_print 1 "$var = $value"
					don=1
				fi
				sect=1
				printf '%s\n' "$tstr"
				;;
			"$shell_ini_config_comment"*|'')
				[ -n "$tstr" ] &&
					__ini_config_print '' "$str" ||
					{ [ -n "$eof" ] || printf '\n'; }
				;;
			*)
				if [ -z "$sect" ]; then
					printf '%s\n' "$str"
					continue
				fi

				shell_var_trim n "${tstr%%=*}"
				shell_var_trim v "${tstr#*=}"

				if [ "$sect" = 2 ] && [ "$n" = "$var" ]; then
					[ -n "$don" ] ||
						__ini_config_print 1 "$n = $value"
					don=1
					continue
				fi
				if [ -z "${tstr##*=*}" ]; then
					__ini_config_print 1 "$n = $v"
				else
					__ini_config_print 1 "$n"
				fi
				;;
		esac

		if [ -n "$eof" ] && [ -z "$don" ]; then
			[ "$sect" = 2 ] ||
				printf '[%s]\n' "$section"
			__ini_config_print 1 "$var = $value"
		fi

	done < "$fn" > "$fn_tmp"
	chmod --reference="$fn" "$fn_tmp"
	mv -f -- "$fn_tmp" "$fn"
}

__ini_config_del_comment()
{
	local fn_tmp sect='' str tstr eof='' n v
	fn_tmp="$(mktemp "$fn.XXXXXX")"

	while [ -z "$eof" ]; do
		IFS='' read -r str || eof=1

		shell_var_trim tstr "$str"

		case "$tstr" in
			"["*"]")
				sect=1
				[ "$tstr" != "[$section]" ] ||
					sect=2
				printf '%s\n' "$tstr"
				;;
			"$shell_ini_config_comment"*|'')
				[ -n "$tstr" ] &&
					__ini_config_print '' "$str" ||
					{ [ -n "$eof" ] || printf '\n'; }
				;;
			*)
				if [ -z "$sect" ]; then
					printf '%s\n' "$str"
					continue
				fi

				shell_var_trim n "${tstr%%=*}"
				shell_var_trim v "${tstr#*=}"

				if [ -z "${tstr##*=*}" ]; then
					if [ "$sect" = 2 ]; then
						__ini_config_action 2 "$n" "$v"
					else
						__ini_config_print 1 "$n = $v"
					fi
				else
					if [ "$sect" = 2 ]; then
						__ini_config_action 1 "$n"
					else
						__ini_config_print 1 "$n"
					fi
				fi
				;;
		esac
	done < "$fn" > "$fn_tmp"
	chmod --reference="$fn" "$fn_tmp"
	mv -f -- "$fn_tmp" "$fn"
	unset -f __ini_config_action
}

### Usage: ini_config_del file section [var]
ini_config_del()
{
	local fn="$1" section="$2" var="${3-}"

	if [ ! -e "$fn" ]; then
		message "No such file or directory: $fn"
		return 1
	fi

	__ini_config_action()
	{
		if [ -n "$var" ] && [ ! "$2" = "$var" ]; then
			[ "$1" = 2 ] &&
				__ini_config_print 1 "$2 = $3" ||
				__ini_config_print 1 "$2"
		fi
	}
	__ini_config_del_comment
}

### Usage: ini_config_comment file section [var]
ini_config_comment()
{
	local fn="$1" section="$2" var="${3-}"

	if [ ! -e "$fn" ]; then
		message "No such file or directory: $fn"
		return 1
	fi

	__ini_config_action()
	{
		if [ -n "$var" ] && [ "$2" != "$var" ]; then
			[ "${1}" = 2 ] && __ini_config_print 1 "$2 = $3" ||
				__ini_config_print 1 "$2"
			return
		fi
		[ "$1" = 2 ] &&
			__ini_config_print 1 "$shell_ini_config_comment $2 = $3" ||
			__ini_config_print 1 "$shell_ini_config_comment $2"

	}
	__ini_config_del_comment
}

fi #__included_shell_ini_config