Argum
Argum is package for parse arguments into struct, inspired by alexflint/go-arg.
WARNING! work in progress, backward compatible is not guaranteed!
go get github.com/sg3des/argumDescription
Setting up available arguments using tags:
argum:"-s"- set short signatureargum:"--str"- set long signatureargum:"-s,--str"- set short and long signatureargum:"req"orargum:"required"- required argumentargum:"pos"orargum:"positional"- positional argumentargum:"oneof"- this keyword work only on internal struct, user can select only one of nested fields, itself structure ignored from command lineargum:"emb"orargum:"embedded"- its keyword work only on for internal struct, and indicates that the struct name should be ignoredhelp:"some help"- help description for this optiondefault:"value"- default value- if struct field not have tag argum, then parse it automate
Argum, use 3 key tags for parse structure - argum, help, default - it's more convenient.
Usage
var args struct {
A string //parsed to -a
Arg string //parsed to --arg
SomeArg string `argum:"-s"` //only -s
OneMoreArg string `argum:"-o,--onemore"` //both keys: -o, --onemore
}
argum.MustParse(&args)Set software version
argum.Version = "some version"
argum.MustParse(&args)Default values
var args struct {
String string `default:"some string"`
Slice []string `default:"one,two,three"`
IntSlice []int `argum:"--int" default:"0,2,3"`
}Default value for slice automatic split by comma character
Joined boolean arguments
var args struct {
A bool
B bool
C bool `argum:"-c"`
D bool
E bool
}
argum.MustParse(&args)This options can be specified as ./example -abcde, and each of listed will be set to true
Internal structs and oneof keyword
var args struct {
Command Commands `argum:"req,oneof" help:"select main command"`
Listen *Echo `help:"optional internal struct"`
Value string `argum:"pos" help:"Some string value"`
Debug bool `argum:"-d,--debug" help:"Enable debug mode"`
}
type Commands struct {
Ping *Ping `help:"some ping"`
Echo *Echo `help:"open local port"`
Str string `argum:"pos" help:"simple string value instead struct"`
}
type Ping struct {
IP string `argum:"req,pos" help:"ip address"`
Count int `argum:"-c" help:"count of packets"`
}
type Echo struct {
Port int `argum:"req,pos" help:"port number"`
}Keyword oneof is means user should chose only one of nested fields. These example structures will provide next command lines:
./example ping 127.0.0.1
./example -d ping 127.0.0.1
./example ping 127.0.0.1 -c4
./example ping 127.0.0.1 -c4 listen 8000
./example echo 8080
./example echo 8080 -d
./example echo 8080 listen 8000
Embedding structs
var args struct {
Ping `argum:"emb"`
}
type Ping struct {
IP string `argum:"pos,req"`
Count int `argum:"-c" help:"count of packets"`
}Keyword emb or embedded indicates that the structure name should be ignored. These example will provide next command lines:
./example 127.0.0.1
./example 127.0.0.1 -c 4
Help and Usage output
var args struct {
A bool `help:"a option, enable something"`
B bool `help:"if true, then something will happen"`
C bool `help:"c enable something"`
S string `argum:"req,str0|str1|str2" help:"required value for something"`
String string `help:"set string value"`
Arg string `argum:"-a" help:"optional you may set Arg variable"`
OneMoreArg string `argum:"-o,--onemore" default:"some-value" help:"one more arg"`
Pos string `argum:"pos,debug|normal|fast" default:"normal" help:"mode"`
}
argum.Version = "example version 0.1.2"
argum.MustParse(&args)usage: example [-abc] -s=[str0|str1|str2] [--string=<s>] [-a=<s>] [-o=<s>] [debug|normal|fast]
positional:
pos mode [default: normal] [debug|normal|fast]
options:
-a a option, enable something
-b if true, then something will happen
-c c enable something
-s=[str0|str1|str2] required value for something [str0|str1|str2]
--string=<s> set string value
-a=<s> optional you may set Arg variable
-o, --onemore=<s> one more arg [default: some-value]
-h, --help display this help and exit
--version display version and exit