How to keep default bash filename completion for positional argument?

[romainreignier]

Hi, I really like how easily complete allows to add completion to CLI tools using flag but since I use it, I have lost the classic bash completion on filenames for positional arguments.

Take this example:

package main

import (
	"flag"
	"fmt"
	"os"

	"github.com/posener/complete/v2"
)

func main() {
	printJSON := flag.Bool("json", false, "prints the filename in JSON")

	complete.CommandLine()
	flag.Parse()

	if flag.NArg() < 1 {
		fmt.Printf("File argument is missing\n\n")
		flag.Usage()
		os.Exit(1)
	}

	if *printJSON {
		fmt.Println("{\"filename\": \"" + flag.Arg(0) + "\"}")
	} else {
		fmt.Println("File: " + flag.Arg(0))
	}
}

Without the complete.CommandLine() line, I do not get completion for the -json flag but my positional argument is well completed by bash. But with this line, I do not get completion anymore.

Is there anything to get the file completion behavior back?

Thank you

[posener]

Hi there,

I am not aware for any fall back option. If there is such, it will be nice to have it. Other than that, I can give you two options:

1. Try the posener/cmd library, where you can easily define completion for positional arguments.
2. Use the Command.Args option

[romainreignier]

Hi @posener

Thank you for your reply.

The solution 1. seems the simpler.

I have then modified my minimal example to:

package main

import (
	"fmt"
	"os"

	"github.com/posener/cmd"
	"github.com/posener/complete/v2/predict"
)

func main() {
	root := cmd.New()
	printJSON := root.Bool("json", false, "prints the filename in JSON")
	args := root.Args("<input_file>", "File to print the name", predict.OptPredictor(predict.Files("*")))
	root.Parse()

	// Could be remplaced with args = make(cmd.ArgsStr, 1) and ArgsVar()
	if len(*args) < 1 {
		fmt.Printf("File argument is missing\n\n")
		root.Usage()
		os.Exit(1)
	}

	if *printJSON {
		fmt.Println("{\"filename\": \"" + (*args)[0] + "\"}")
	} else {
		fmt.Println("File: " + (*args)[0])
	}
}

Without the --json flag, the positional argument is completed but when the boolean flag is used, the file completion does not work.

What would be the correct usage?

Thank you

[posener]

Hi

Right, it seems to be a bug... :disappointed:

$ ./test <tab>
./       go.mod   go.sum   -h       -json    main.go  test

But ./test -json<tab> adds space, and then ./test -json <tab> adds dash, and then:

$ ./test -json -
-h     -json