#Optparse A BASH wrapper for getopts and compgen, for simple command-line argument parsing an bash completion.

##What is this? A wrapper that provides a clean and easy way to parse arguments and create Tab completion to your BASH scripts. You could also create wrappers for linux commands. It let you define short and long option names, handle flag variables, set default values for optional arguments and an optional list of posible values for options to complete, all while aiming to be as minimal as possible: One line per argument definition.

##Usage ###1. Install bash-completion package from your linux repository. ###2. Create a script to generate completion and option parsing files. ###3. Source file optparse.bash in the script. ###4. Define your arguments in the script.

Each argument to the script is defined with optparse.define, which specifies the option names, a short description, the variable it sets, the default value (if any) and a list of posible values (if any). Also you could define options as required to your script. If you use filesystem file parameters you could define the parameter as a file.

optparse.define short=n long=name desc="The event name" variable=name

Flags are defined in exactly the same way, but with an extra parameter value that is assigned to the variable.

optparse.define short=s long=say-hello desc="Say Hello" variable=say_hello value=true default=false

Posible arguments could be defined in exactly the same way, but with an extra parameter list that is assigned to the variable.

optparse.define short=c long=country desc="The event country" variable=country list="USA Canada Japan Brasil England"

Required parameters are defined in exactly the same way, but with an extra parameter required that is assigned to the variable.

optparse.define short=y long=year desc="The event year" variable=year required=true

Another way to pass a completion list is to assign a command output to list variable as follow.

optparse.define short=y long=year desc="The event year" variable=year list="\$(my_command)"

File parameters are defined in exactly the same way, but with an extra parameter file that is assigned to the variable. See wget_dir_generate_completion.sh as example.

optparse.define short=x long=directory-prefix desc="Destination directory to save all files" variable=directory file=true required=true

###5. Evaluate your arguments The optparse.build function creates a header script and a configuration file in /etc/bash_completion.d/ based on the provided argument definitions.

optparse.build script_name

If you want to generate completion file in another location, you could path location as parameter to optparse.build function.

optparse.build script_name "."

###6. Allow execution to the script and execute it as sudo.

See sample_event_generate_completion.sh for a demonstration. For a more complex example see wget_dir_generate_completion.sh.

###7. Source profile bash completion configuration, example:

$ source /etc/bash_completion

###8. In your command script( The script to parse arguments and generate completion ) source the optparse generated file to parse and evaluate arguments. Also you could check if there are missing options.

####That's it! The script can now show completion and make use of the variables. Running the script (without any arguments) should give you a neat usage description.

usage: ./script.sh [OPTIONS]

OPTIONS:

    -n --name  :  The event name
    -s --say-hello:  Say Hello [default:false]
	-c --country  :  The country name
	-y --year  :  The year

	-? --help  :  usage

See sample_event.sh for a demonstration. For a more complex example see wget_dir.sh.

Now to use the command script we can write:

$ ./sample_event.sh [TAB][TAB]
$ --name --country --year
$ ./sample_event.sh --country [TAB][TAB]
$ USA Canada Japan Brasil
$ ./sample_event.sh --name "Football World Cup" --country Brasil --year 2014
$ The Football World Cup will be in Brasil in 2014.
$ ./sample_event.sh --sey-hello --name "Football World Cup" --country Brasil --year 2014
$ Hello!!! The Football World Cup will be in Brasil in 2014.

##Supported definition parameters All definition parameters for optparse.define are provided as key=value pairs, seperated by an = sign. ####short a short, single-letter name for the option ####long a longer expanded option name ####variable the target variable that the argument represents ####value(optional) the value to set the variable to. If unspecified, user is expected to provide a value. ####desc(optional) a short description of the argument (to build the usage description) ####default(optional) the default value to set the variable to if argument not specified ####list(optional) the list of posible arguments for an option to autocomplete. It could be a list of strings or a command. ####required(optional) the requirement for the option

##Installation

1. Download/clone optparse.bash