Merge branch 'develop'

Author: moebrowne

README.md

@@ -1 +1,114 @@
-# BASH Argument Parser
+# BASH Argument Parser
+
+Takes arguments passed in nearly any format to a bash script and allows easy access to them and their values
+
+## Use
+
+### Get An Arguments Value
+
+There is a helper function named `argValue()` which takes the name of 
+an argument as its only parameter and returns the value given to the argument.
+
+If the argument doesn't have a value or hasn't been passed nothing is returned.
+
+```bash
+
+	# -a 'some text'
+	if [ "$(argValue "a")" == 'some text' ]; then
+		# Do something awesome
+	fi
+	
+	# --debug 3
+	DEBUG_LEVEL="$(argValue "debug")" # 3
+	
+	# -R 0
+	[ "$(argValue "R")" == "0" ] && echo "Recursive depth 0"
+	
+	# -aXb 'cookie'
+	BISCUIT="$(argValue "b")" # 'cookie'
+	
+	# -g 'hello' -G 'world'
+	ALPHA="$(argValue "g")" # 'hello'
+	BRAVO="$(argValue "G")" # 'world'
+	
+	# -S d
+	case $(argValue 'S') in
+		a)	echo "something" ;;
+		b)	echo "something" ;;
+		c)	echo "something" ;;
+		d)	echo "darkside"  ;;
+	esac
+	
+```
+
+### Check If An Argument Has Been Passed
+
+There is a helper function named `argExists()` which takes the name of 
+an argument as its only parameter and returns a boolean.
+
+```bash
+	
+	# -v
+	if argExists 'v'; then
+    	echo "The -v argument has been passed"
+    fi
+    
+    # -rMd
+	argExists 'r' && echo "The -r argument was passed"
+    
+    # --long-argument-name
+	if argExists 'long-argument-name'; then
+    	# Do something awesome
+    fi
+    
+    # -O 43
+    argExists 'r' && echo "Found the -O argument"
+
+```
+
+## Supported Argument Formats
+
+### Short Form
+
+```bash
+	-a
+	-X
+	-b somevalue
+	-c 38
+	-d "some value with spaces"
+	-e "some value with
+newlines"
+```
+
+### Long Form
+
+```bash
+	--debug
+	--test mode0
+	--test "all the code"
+	--Case-Sensitive true
+	--long-parameter
+	--newline "
+"
+```
+
+### Chained Short Form Arguments
+
+```bash
+	-aih	# Equivalent to -a -i -h
+	-dav 4	# Equivalent to -d -a -v 4
+```
+
+## Argument Order
+
+The order the arguments are passed on the command line makes a difference
+
+### Examples
+
+* Calling `my-script.sh -f first -f last` will cause `${args["f"]}` to have the value `last`
+* Calling `my-script.sh -g 345 -g` will mean cause `${args["g"]}` to be blank
+
+## Debug Mode
+
+There is a debug mode that can be enabled by setting the `ARG_DEBUG` variable at the top of the script to `true`.
+This will cause the script to dump out information about which flags it finds and of what kind etc

argument-parser.sh

@@ -0,0 +1,111 @@
+#!/bin/bash
+
+# Define the regex for matching the arguments
+regexArgShort='^-([a-zA-Z])$'
+regexArgShortChained='^-([a-zA-Z]{2,})$'
+regexArgLong='^--([a-zA-Z\-]{2,})$'
+
+argChunks=()
+
+ARG_DEBUG=false
+
+# Expand chained short form arguments, eg -aih => -a -i -h
+for argChunk in "$@"; do
+
+	# See if this argument is a chained short form argument
+	[[ $argChunk =~ $regexArgShortChained ]]
+	if [ "${BASH_REMATCH[1]}" != "" ]; then
+
+		# Get the chunk or arguments
+		chainedChunk="${BASH_REMATCH[1]}";
+
+		[ $ARG_DEBUG == true ] && echo "Expanding chained argument chunk: $chainedChunk"
+
+		i=0
+		# Expand out the chunk into individual arguments
+		while (( i++ < ${#chainedChunk} )); do
+
+			# Get just the argument on its own
+			argumentIsolated="${chainedChunk:$i-1:1}"
+
+			# Add the isolated argument to the argument chunk array
+			argChunks+=("-$argumentIsolated")
+		done
+		continue;
+	fi
+
+	# Add the argument to the argument array
+	argChunks+=("$argChunk")
+done
+
+[ $ARG_DEBUG == true ] && echo "Expanded argument list: ${argChunks[@]}"
+
+# Initialise some variables
+declare -A args
+lastWasArgument=0
+lastArgument=""
+
+# Loop over all the argument chunks and determine if the argument type and value
+for argChunk in "${argChunks[@]}"; do
+
+	# Check if this chunk is a short form argument
+	[[ $argChunk =~ $regexArgShort ]]
+	if [ "${BASH_REMATCH[1]}" != "" ]; then
+		argument="${BASH_REMATCH[1]}"
+		lastWasArgument=1
+		lastArgument="$argument"
+
+		# Add the argument to the arguments array
+		args["${BASH_REMATCH[1]}"]=''
+
+		[ $ARG_DEBUG == true ] && echo "Argument (short): ${BASH_REMATCH[1]}"
+
+		continue;
+	fi
+
+	# Check if this chunk is a long form argument
+	[[ $argChunk =~ $regexArgLong ]]
+	if [ "${BASH_REMATCH[1]}" != "" ]; then
+		argument="${BASH_REMATCH[1]}"
+		lastWasArgument=1
+		lastArgument="$argument"
+
+		# Add the argument to the arguments array
+		args["${BASH_REMATCH[1]}"]=''
+
+		[ $ARG_DEBUG == true ] && echo "Argument (long): ${BASH_REMATCH[1]}"
+
+		continue;
+	fi
+
+	# If the last chunk was an argument and this wasn't assume its an argument value
+	if [ $lastWasArgument == 1 ]; then
+
+		# Add the arguments value to the arguments array
+		args["$lastArgument"]="$argChunk"
+
+		[ $ARG_DEBUG == true ] && echo "Argument Value: $argChunk"
+
+		lastWasArgument=0
+	fi
+done
+
+[ $ARG_DEBUG == true ] && echo "Argument array:"
+[ $ARG_DEBUG == true ] && for k in "${!args[@]}"
+do
+    echo "ARG: $k = ${args[$k]}"
+done
+
+argExists() {
+	if [ -z ${args["$1"]+abc} ]; then
+		return 1
+	else
+		return 0
+	fi
+}
+
+argValue() {
+	if argExists "$1"; then
+		echo "${args["$1"]}"
+	fi
+}