shell-git-config

#!/bin/ash -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_git_config-}" ]; then
__included_shell_git_config=1

. shell-error
. shell-var
. shell-string

GIT_CONFIG_GET_RAW=
GIT_CONFIG_INCLUDE=1

__git_config_lc()
{
	local __lc="$2"
	[ -n "${2##*[A-Z]*}" ] ||
		__lc="$(printf '%s' "$2" |tr '[:upper:]' '[:lower:]')"
	eval "$1=\"\$__lc\""
}

# Parse incoming argument into pieces
__git_config_split()
{
	[ -z "${1##*.*}" ] ||
		fatal " key does not contain a section: $1"

	local sl nl

	__git_config_section="${1%%.*}"
	[ -n "${__git_config_section##*[!A-Za-z0-9-]*}" ] ||
		fatal "bad section name: $__git_config_section"
	__git_config_lc sl "$__git_config_section"

	__git_config_name="${1##*.}"
	[ -n "${__git_config_name##*[!A-Za-z0-9-]*}" ] ||
		fatal "bad variable name: $__git_config_name"
	__git_config_lc nl "$__git_config_name"

	__git_config_subsection="${1#*.}"
	[ "$__git_config_subsection" != "$__git_config_name" ] &&
		__git_config_subsection="${__git_config_subsection%.*}" ||
		__git_config_subsection=

	__git_config_location="$sl${__git_config_subsection:+.$__git_config_subsection}"
	__git_config_fullpath="$__git_config_location.$nl"
}

__git_config_fullpath()
{
	local __git_config_section __git_config_name __git_config_subsection
	__git_config_split "$1"
}

__git_config_value()
{
	local dq= bq= c= m= l="$1"
	fill_mask m "$l"

	value=
	while [ -n "$l" ]; do
		c="${l%$m}"
		l="${l#?}"
		m="${m#?}"

		case "$c" in
			\\)
				if [ -z "$bq" ]; then
					bq=1
					c=
				else
					bq=
				fi
				;;
			\")
				if [ -z "$bq" ]; then
					[ -z "$dq" ] && dq=1 || dq=
					c=
				else
					bq=
				fi
				;;
			b|n|t)
				if [ -n "$bq" ]; then
					bq=
					c="$(printf "\\$c#")"
					c="${c%#}"
				fi
				;;
			*)
				bq=
				;;
		esac
		value="$value$c"
	done

	[ -z "$dq" ] ||
		fatal "bad config file line $nline in $fn"
}

__git_config_handler() { :; }
__git_config_parser()
{
	local fn="$1" name value section= subsection= section_lower= name_lower= location= line oline nline=0 eof=

	__git_config_parse_section()
	{
		local line="$1" invalid='[!A-Za-z0-9-.]'

		if [ -n "$section" ]; then
			location="$section_lower${subsection:+.$subsection}"
			__git_config_handler 'section-end'
		fi

		section="$line"
		subsection=

		if [ -z "${line##*[ 	]*}" ]; then
			section="${line%%[ 	]*}"
			subsection="${line#*[ 	]\"}"
			subsection="${subsection%\"}"
			invalid="[!A-Za-z0-9-]"
		fi

		[ -n "${section##*$invalid*}" ] ||
			fatal "bad config file line $nline in $fn"

		__git_config_lc section_lower "$section"

		location="$section_lower${subsection:+.$subsection}"
		__git_config_handler 'section-start'
	}
	__git_config_parse_variable()
	{
		shell_var_trim name "${1%%=*}"

		[ -z "${1##*=*}" ] &&
			shell_var_trim value "${1#*=}" ||
			value='true'

		shell_var_unquote value "$value"

		[ -n "${GIT_CONFIG_GET_RAW-}" ] ||
			__git_config_value "$value"

		__git_config_lc name_lower "$name"

		location="$section_lower.${subsection:+$subsection.}$name_lower"
		__git_config_handler 'variable'
	}
	__git_config_parse_include()
	{
		[ "$location" = 'include.path' ] ||
			return 0

		local i="$1"

		[ -n "${i##\~/*}" ] ||
			i="$HOME/${i#\~/}"

		[ -n "${i##\~*}" ] ||
			fatal "expression isn't supported at line $nline in $fn"

		[ ! -e "$i" ] ||
			__git_config_parser "$i"
	}

	oline=
	while [ -z "$eof" ]; do
		nline=$(($nline + 1))

		IFS= read -r line || eof=1

		line="$oline$line"
		oline=

		case "$line" in
			'')
				;;
			*\\)
				oline="$line"
				;;
			'#'*|';'*)
				__git_config_handler 'comment'
				;;
			'['*']'[' 	']*[!' 	']*)
				fatal "expression isn't supported at line $nline in $fn"
				;;
			'['*']')
				line="${line#\[}"
				line="${line%\]}"
				__git_config_parse_section "$line"
				;;
			*)
				__git_config_parse_variable "$line"

				[ -z "$GIT_CONFIG_INCLUDE" ] ||
					__git_config_parse_include "$value"
				;;
		esac
	done < "$fn"

	[ -n "$section" ] ||
		return 0
	location="$section_lower${subsection:+.$subsection}"
	__git_config_handler 'section-end'
}

### Checks whether there is a specified variable in the configuration.
### Usage: git_config_location_exists file name
git_config_location_exists()
{
	local __git_config_location_exists=1 __git_config_fullpath __git_config_location
	__git_config_handler()
	{
		[ "$__git_config_fullpath" != "$location" ] ||
			__git_config_location_exists=0
	}
	__git_config_fullpath "$2"
	__git_config_parser "$1"
	return $__git_config_location_exists
}

### Gets variable from specified config file and store result into variable.
### Usage: git_config_get retname file name
git_config_get()
{
	local __git_config_v= __git_config_fullpath __git_config_location
	__git_config_handler()
	{
		[ "$1" != 'variable' -o "$__git_config_fullpath" != "$location" ] ||
			__git_config_v="$value"
	}
	__git_config_fullpath "$3"
	__git_config_parser "$2"
	eval "$1=\"\$__git_config_v\""
}

### Counts variable occurrences in specified config file and store result into variable.
### Usage: git_config_count retname file name
git_config_count()
{
	local __git_config_v=0 __git_config_fullpath __git_config_location
	__git_config_handler()
	{
		[ "$1" != 'variable' -o "$__git_config_fullpath" != "$location" ] ||
			__git_config_v=$(($__git_config_v + 1))
	}
	__git_config_fullpath "$3"
	__git_config_parser "$2"
	eval "$1=\"\$__git_config_v\""
}

### Lists values of variable in specified config file.
### Usage: git_config_list file [name]
git_config_list()
{
	local __git_config_fullpath= __git_config_location=
	__git_config_handler()
	{
		[ "$1" = 'variable' ] ||
			return 0
		if [ -n "$__git_config_location" ]; then
			[ "$__git_config_fullpath" != "$location" ] ||
				printf '%s\n' "$value"
		else
			printf '%s=%s\n' "$location" "$value"
		fi
	}
	[ -z "${2-}" ] ||
		__git_config_fullpath "$2"
	__git_config_parser "$1"
}

### Lists all names and variables in tab separated form.
### Usage: git_config_parse file
git_config_parse()
{
	__git_config_handler()
	{
		[ "$1" = 'variable' ] ||
			return 0
		printf '%s\t%s\n' "$location" "$value"
	}
	__git_config_parser "$1"
}

### Append another value with same name into config file.
### Usage: git_config_append file name value
git_config_append()
{
	local GIT_CONFIG_INCLUDE= GIT_CONFIG_GET_RAW=1
	local __git_config_section __git_config_name __git_config_subsection __git_config_fullpath __git_config_location
	local __git_config_nvalue="$3"
	local __git_config_state=0 fn

	[ -f "$1" ] || :> "$1"

	__git_config_split "$2"

	__git_config_handler()
	{
		case "$1" in
			comment)
				printf '%s\n' "$line"
				;;
			variable)
				printf '\t%s = %s\n' "$name" "$value"
				if [ "$__git_config_fullpath" = "$location" -a $__git_config_state != 1 ]; then
					printf '\t%s = %s\n' "$__git_config_name" "$__git_config_nvalue"
					__git_config_state=1
				fi
				;;
			section-start)
				printf '[%s]\n' "$section${subsection:+ \"$subsection\"}"
				;;
			section-end)
				if [ "$__git_config_location" = "$location" -a $__git_config_state != 1 ]; then
					printf '\t%s = %s\n' "$__git_config_name" "$__git_config_nvalue"
					__git_config_state=1
				fi
				;;
		esac
	}
	fn="$(mktemp "$1.XXXXXX")"
	__git_config_parser "$1" > "$fn"

	if [ $__git_config_state -eq 0 ]; then
		printf '[%s]\n\t%s = %s\n' \
			"$__git_config_section${__git_config_subsection:+ \"$__git_config_subsection\"}" \
			"$__git_config_name" "$__git_config_nvalue" >> "$1"
		rm -f -- "$fn"
	else
		mv -f -- "$fn" "$1"
	fi
}

### Set or add value into config file.
### Usage: git_config_set file name value
git_config_set()
{
	local GIT_CONFIG_INCLUDE= GIT_CONFIG_GET_RAW=1
	local __git_config_section __git_config_name __git_config_subsection __git_config_fullpath __git_config_location
	local __git_config_nvalue="$3" __git_config_ovalue=
	local __git_config_state=0 fn

	[ -f "$1" ] || :> "$1"

	__git_config_split "$2"
	git_config_get __git_config_ovalue "$1" "$2"

	__git_config_handler()
	{
		case "$1" in
			comment)
				printf '%s\n' "$line"
				;;
			variable)
				if [ "$__git_config_fullpath" = "$location" -a -n "$__git_config_ovalue" ]; then
					if [ "$__git_config_ovalue" = "$value" ]; then
						printf '\t%s = %s\n' "$__git_config_name" "$__git_config_nvalue"
						__git_config_state=1
					fi
				else
					printf '\t%s = %s\n' "$name" "$value"
				fi
				;;
			section-start)
				printf '[%s]\n' "$section${subsection:+ \"$subsection\"}"
				;;
			section-end)
				if [ "$__git_config_location" = "$location" -a $__git_config_state != 1 ]; then
					printf '\t%s = %s\n' "$__git_config_name" "$__git_config_nvalue"
					__git_config_state=1
				fi
				;;
		esac
	}
	fn="$(mktemp "$1.XXXXXX")"
	__git_config_parser "$1" > "$fn"

	if [ $__git_config_state -eq 0 ]; then
		printf '[%s]\n\t%s = %s\n' \
			"$__git_config_section${__git_config_subsection:+ \"$__git_config_subsection\"}" \
			"$__git_config_name" "$__git_config_nvalue" >> "$1"
		rm -f -- "$fn"
	else
		mv -f -- "$fn" "$1"
	fi
}

### Usage: git_config_unset file name [value]
git_config_unset()
{
	local GIT_CONFIG_INCLUDE= GIT_CONFIG_GET_RAW=1
	local __git_config_section __git_config_name __git_config_subsection __git_config_fullpath __git_config_location
	local __git_config_ovalue="${3-}"
	local fn

	[ -f "$1" ] || :> "$1"
	__git_config_split "$2"

	__git_config_handler()
	{
		case "$1" in
			comment)
				printf '%s\n' "$line"
				;;
			variable)
				if [ "$__git_config_fullpath" = "$location" ]; then
					[ -z "$__git_config_ovalue" -o "$__git_config_ovalue" = "$value" ] ||
						printf '\t%s = %s\n' "$name" "$value"
				else
					printf '\t%s = %s\n' "$name" "$value"
				fi
				;;
			section-start)
				printf '[%s]\n' "$section${subsection:+ \"$subsection\"}"
				;;
		esac
	}
	fn="$(mktemp "$1.XXXXXX")"
	__git_config_parser "$1" > "$fn"
	mv -f -- "$fn" "$1"
}

fi #__included_shell_git_config