Add support for a config file

README.md

@@ -2,7 +2,11 @@
 
 A tool to play a plaintext playlist composed entirely of youtube-dl search queries
 
-## Setup
+## Installation
+
+Put `ptgdp` somewhere in `$PATH` and install `youtube-dl`.
+
+## Quickstart
 
 Make a file containing a few download queries. For example:
 
@@ -20,6 +24,10 @@ Then invoke `ptgdp`:
 
 See below for more intricate usage.
 
+## Configuration
+
+Move `ptgdp.conf` from this repo to `~/.config/ptgdp.conf` and change the values as you see fit.
+
 ## License
 
 See `LICENSE` (hint: it's MIT, just like the header says).

ptgdp

@@ -9,7 +9,12 @@ set -e
 
 # Read-only set-once variables
 declare -r _name="$(basename -- "$0")"
+declare -ra _supportedbackends=("mpd")
 # Options
+declare -A _config=(
+	[backend]="mpd"
+)
+declare _optconfigfile="${XDG_CONFIG_HOME:-$HOME/.config}/${_name}.conf"
 declare -i _opthelp
 declare -i _optverbose=0
 # Working variables
@@ -54,6 +59,7 @@ Usage: $_name [OPTION]... [FILE]...
 Use youtube-dl and a music player to queue up or download a number of songs
 given plaintext files with only search queries
 
+  -c [FILE]		Load the given file in place of the usual config file
   -h			Print this help text
   -v			Print more status messages. Stacks
 
@@ -65,8 +71,11 @@ EOF
 # Main
 main() {
 	# Getopts before anything else
-	while getopts ":hv" opt; do
+	while getopts ":c:hv" opt; do
 		case $opt in
+			c)
+				_optconfigfile="$OPTARG"
+				;;
 			h)
 				_opthelp=1
 				;;
@@ -81,7 +90,26 @@ main() {
 				;;
 		esac
 	done
-
+	# Parse out a config file if it exists
+	if [ -f "$_optconfigfile" ]; then
+		log "Loading config file" 1
+		while read line; do
+			# If the line has an equals sign and isn't a comment
+			if [ "$line" != "${line#*=}" ] && [ "$line" = "${line#\#}" ]; then
+				local varname="${line%=*}"
+				local value="${line#*=}"
+				_config[$varname]="$value"
+				log "Setting $varname to $value" 1
+			fi
+		done < "$_optconfigfile"
+	fi
+	# Validate critical options
+	{
+		for backend in ${_supportedbackends[@]}; do
+			[ "$backend" = "${_config[backend]}" ] && return 0
+		done
+		error "Unsupported backend: ${_config[backend]}" 50
+	}
 	# Pre-really-do-stuff hooks like help text
 	[ -n "$_opthelp" ] && printhelp && exit 0
 

ptgdp.conf

@@ -0,0 +1,9 @@
+#
+# ptgdp.conf
+# Config file for Play the Goddamned Playlist
+#
+
+# The media player backend to use
+# Supported: mpd
+# Default: mpd
+backend=mpd