README
¶
getopt library For Go
This is a very simple library for getopt-style argument/option
parsing, written in and for Go. It supports both traditional "short"
options (like -a, -b 1, -dfe, etc), and the GNU-style "long"
options (like --help, --fix=everything, etc).
I strongly believe that
exposing a common and familiar user interface in your programs is
important; the getopt-style command line argument parsing is the
single most universally accepted convention, dating back to at least
1980, and widely supported by many platforms, languages, and utilities.
Unfortunately, Go's standard flag module ignores that convention, and proposes its own. This package offers a simple alternative.
Example
You can find more examples in the examples directory of the source distribution.
package main
import (
"github.com/rollcat/getopt"
"os"
)
func main() {
args, opts, err := getopt.GetOpt(
os.Args[1:],
"hv",
nil,
)
if err != nil || len(args) > 0 {
println("Usage: program [-hv]")
os.Exit(1)
}
for _, opt := range opts {
switch opt.Opt() {
case "-v":
println("Version 0.1")
os.Exit(0)
case "-h":
println("Usage: program [-hv]")
os.Exit(0)
default:
panic("unexpected argument")
}
}
}
Documentation
On pkg.go.dev.
You can also use godocs, or the command line:
go doc github.com/rollcat/getopt
Author and license
Original code by Tim Henderson <tim.tadh@gmail.com>.
This fork, and all of its opinionated tweaks, by Kamil Cholewiński <kamil@rollc.at>.
License is BSD.
Documentation
¶
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type OptArg ¶
OptArg represents a single parsed option (and its argument, if applicable), as parsed by GetOpt.
func GetOpt ¶
func GetOpt( args []string, shortopts string, longopts []string, ) ( leftovers []string, optargs []OptArg, err error, )
GetOpt parses the provided args, according to shortopts and longopts; and returns the leftover args, parsed options with their arguments, and (if there was one) any encountered parsing error.
See the package documentation for a description of the shortops and longopts formats, as well as how the args are interpreted in their context.
If there is a programming error in shortopts or longopts (rather than a parsing error resulting from unexpected arguments in the resulting program), GetOpt may cause a runtime panic.
func GetOptSafe ¶
func GetOptSafe( args []string, shortopts string, longopts []string, ) ( leftovers []string, optargs []OptArg, err error, )
GetOptSafe works identically to GetOpt, but will not trigger runtime panics on errors such as programmer mistakes in shortopts or longopts. This is for situations, where you'd like to implement getopt(1), or otherwise allow the end user to specify their own shortops/longopts, and get a useful error message rather than a stack trace.
type ParseError ¶
type ParseError struct {
// message and opt are used to build the friendly user-facing
// error message.
Message string
Opt string
// This can be somewhat useful in debugging.
Unexpected string
Expected string
// contains filtered or unexported fields
}
ParseError contains hints about what exactly went wrong when parsing the arguments in GetOpt. The resulting message (ParseError.Error()) should be displayed to the user.
func (ParseError) Error ¶
func (err ParseError) Error() string
Source Files
Directories
¶
| Path | Synopsis |
|---|---|
|
This tiny example program serves as a little stress-test, attempting to parse (only parse!) all arguments supported by GNU coreutils ls(1).
|
This tiny example program serves as a little stress-test, attempting to parse (only parse!) all arguments supported by GNU coreutils ls(1). |