README

This is a simple script and a test-program that emulates the argparse python-like functionality in bash.

You can call the script with the options specified using the long and short names. For the usage, please, see the test examples scripts. test_types.sh

There are 4 functions:

• add_argument: to add comman line options.

  The command line arguments can be defined with 5 options:

  • -a short name for argument [mandatory]

  • -l long name for argument [optional default: ""]

  • -d default value [else, the argument becomes mandatory]. The default value is checked to assert they follow a valid regex to convert to the type.

  • -h docstring [optional default: "Not documented"]

  • -t Type of the parameters (string int float bool path file enum timer list) [optional default: string]

  • -e The list of valid values when using enum. The argument is used and required ONLY when -t enum. It expects a simple list like: opt1,opt2 ...

    Ex: add_argument -a e -l myenum -h "Enum option" -t enum -e option1,option2 -d option1

• parse_args: to parse the command line arguments or any list

  This one can be called passing any list of arguments to process for example: parse_args "$@"

  At the end of this function it checks that the mandatory arguments have a non-empty value.

  Every value is checked to assert they match a regex valid for their type.

• printargs: prints the arguments defined in the script and the values.

  Useful for debug purposes and to print the help. This function can receive a parameter to add as a prefix before every printed line; this is useful to add comments before the printed lines:

  Example: printargs #

• argparse_check: checks the values to match the parameter types. This is an internal function and the user shouldn't need to use it.

  The valid types are: (string int float bool path file enum timer list)

  In case of path and file it checks that the path or the file exists in the filesystem.

  In case of float it accepts formats like 3.14 or 3.

  In case of enum if checks that the enum is one of the valid options.

  In case of timer the expected format is H+:mm:ss. mm and ss are limited to 00 -> 60. But H+ means any valid positive integer.

  All the strings are valid but it is assumed that they don't contain spaces.

  In case of list currently the valid values are only integers and are set like "1,2,34,56" (quotes not required.)

Accessing parameters

The values can be accessed throw the global arrays created as ARGS[short] or LONG_ARGS[long].

The help can be accessed as HELP_ARGS[short].

There are names restrictions for the script variables as all the variables in bash are public by default. Also, for simplicity, please read the script.

These names are forbidden because we use them internally, and they are public variables.

• ARGS: associative array with the values, index short name. Ex: ${ARGS[e]}

• LONG_ARGS: associative array with the values, index long name. Ex: ${LONG_ARGS[myenum]}

• MAP_LONG_ARGS: Map from short to long names. Usually not needed by the user.

• MAP_ARGS_LONG: Map from long to short names. Usually not needed by the user

• HELP_ARGS: Help string arrays. Index short.

• MANDATORY: Array that returns is the argument is mandatory

• ARG_TYPE: Array that returns the argument type

This is a WIP and of course can be improved, if you use/improve it or you find any error/issue, please, contact me in order to improve, correct or add you as a collaborator in this project.

The bool variables do not require a parameter, in fact it is ignored if provided and the variable is only switched between true and false. If you want to use a boolean variable that accepts true or false y recommend to use an enum instead like:

add_argument -a b -l mybool -h "Bool option with input" -t enum -e true,false -d false

An extra REST argument is automatically added when some extra command line arguments are added at the end of the input. This can be accessed like: ARGS[REST] and in spite of it is not a list, it is iterable or can be passed to other commands. Ex: echo ${ARGS[REST]} | wc -w returns the number of elements (words) in the list.

Or:

for i in ${ARGS[REST]}; do
	echo $i
done

is also valid.

This is under GPLv3 license

author: Jimmy Aguilar Mena

date: 06/03/2018