getopt

Yet Another GetOpt Library For Go

By Tim Henderson (tim.tadh@gmail.com)

BSD Licenced

Motivation

The existing libraries[1,2,3,4] don't exactly work how I would like them to work. Specifically, I want it to work exactly like how the Python getopt module works. The reason being, that particular implementation has proven through years of use to be incredibly scalable and flexible. While, there are definitely easier to use approaches (see for instance argparse) none have the flexibility of the simple getopt.

The current solutions also try to do too much while not implementing the basic functionality in a sensible way. This library will simply pull out a list of the flags found, and their options (as strings). Parsing the arguments into Go datatypes will be up to the user of the library.

Todo

1. Lots more tests (currently it only tests basic functionality, complex situations are probably missed.)

Contributing

1. "Fork"
2. Make a feature branch.
3. Do your commits
4. Send "pull request". This can be
   1. A github pull request
   2. A issue with a pointer to your publicly readable git repo
   3. An email to me with a pointer to your publicly readable git repo

Docs

PACKAGE

package getopt
    import "github.com/timtadh/getopt"


FUNCTIONS

func GetOpt(
    args []string,
    shortopts string,
    longopts []string,
) (
    leftovers []string,
    optargs []OptArg,
    err error,
)
    GetOpt works like `getopt` in python's `getopt` module in the stdlib
    (modulus implementation bugs).

    params

  args - the argv []string slice
  shortopts - a string of options (similar to what GNU's getopt excepts).
              Options which desire an argument should have a colon, ":",
              subsequent to them. There are no optional arguments at this
              time.
              ex. "hvx:r" would accept -h -v -x asdf -r
  longopts - a list of strings which describe the long options (eg those with
             "--" in front). Placing an = on the end indicates a required
             argument.
             ex. []string{"help", "example="}
               would accept --help --example=tom


TYPES

type OptArg interface {
    Opt() string
    Arg() string
}
    The GetOpt function will return a list of OptArgs. If there is no arg
    then Arg() will return "". Opt will contain a leading "-" for short and
    "--" for long args.

Footnotes

• [1] flag
• [2] https://github.com/droundy/goopt
• [3] https://github.com/jteeuwen/go-pkg-optarg
• [4] https://github.com/kesselborn/go-getopt