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|
package arg
import (
"fmt"
"os"
"strings"
)
func split(s string) []string {
return strings.Split(s, " ")
}
// This example demonstrates basic usage
func Example() {
// These are the args you would pass in on the command line
os.Args = split("./example --foo=hello --bar")
var args struct {
Foo string
Bar bool
}
MustParse(&args)
fmt.Println(args.Foo, args.Bar)
// output: hello true
}
// This example demonstrates arguments that have default values
func Example_defaultValues() {
// These are the args you would pass in on the command line
os.Args = split("./example")
var args struct {
Foo string
}
args.Foo = "default value"
MustParse(&args)
fmt.Println(args.Foo)
// output: default value
}
// This example demonstrates arguments that are required
func Example_requiredArguments() {
// These are the args you would pass in on the command line
os.Args = split("./example --foo=abc --bar")
var args struct {
Foo string `arg:"required"`
Bar bool
}
MustParse(&args)
fmt.Println(args.Foo, args.Bar)
// output: abc true
}
// This example demonstrates positional arguments
func Example_positionalArguments() {
// These are the args you would pass in on the command line
os.Args = split("./example in out1 out2 out3")
var args struct {
Input string `arg:"positional"`
Output []string `arg:"positional"`
}
MustParse(&args)
fmt.Println("In:", args.Input)
fmt.Println("Out:", args.Output)
// output:
// In: in
// Out: [out1 out2 out3]
}
// This example demonstrates arguments that have multiple values
func Example_multipleValues() {
// The args you would pass in on the command line
os.Args = split("./example --database localhost --ids 1 2 3")
var args struct {
Database string
IDs []int64
}
MustParse(&args)
fmt.Printf("Fetching the following IDs from %s: %v", args.Database, args.IDs)
// output: Fetching the following IDs from localhost: [1 2 3]
}
// This eample demonstrates multiple value arguments that can be mixed with
// other arguments.
func Example_multipleMixed() {
os.Args = split("./example -c cmd1 db1 -f file1 db2 -c cmd2 -f file2 -f file3 db3 -c cmd3")
var args struct {
Commands []string `arg:"-c,separate"`
Files []string `arg:"-f,separate"`
Databases []string `arg:"positional"`
}
MustParse(&args)
fmt.Println("Commands:", args.Commands)
fmt.Println("Files:", args.Files)
fmt.Println("Databases:", args.Databases)
// output:
// Commands: [cmd1 cmd2 cmd3]
// Files: [file1 file2 file3]
// Databases: [db1 db2 db3]
}
// This example shows the usage string generated by go-arg
func Example_usageString() {
// These are the args you would pass in on the command line
os.Args = split("./example --help")
var args struct {
Input string `arg:"positional"`
Output []string `arg:"positional"`
Verbose bool `arg:"-v" help:"verbosity level"`
Dataset string `help:"dataset to use"`
Optimize int `arg:"-O,help:optimization level"`
}
// This is only necessary when running inside golang's runnable example harness
osExit = func(int) {}
MustParse(&args)
// output:
// Usage: example [--verbose] [--dataset DATASET] [--optimize OPTIMIZE] INPUT [OUTPUT [OUTPUT ...]]
//
// Positional arguments:
// INPUT
// OUTPUT
//
// Options:
// --verbose, -v verbosity level
// --dataset DATASET dataset to use
// --optimize OPTIMIZE, -O OPTIMIZE
// optimization level
// --help, -h display this help and exit
}
|
