status-im/status-go

package main

import (
    "fmt"
    "os"
    "path"
    "strings"
)

// configFlags represents an array of JSON configuration files passed to a command line utility
type configFlags []string

func (f *configFlags) String() string {
    return strings.Join(*f, ", ")
}

func (f *configFlags) Set(value string) error {
    if !path.IsAbs(value) {
        // Convert to absolute path
        cwd, err := os.Getwd()
        if err != nil {
            return err
        }
        value = path.Join(cwd, value)
    }

    // Check that the file exists
    stat, err := os.Stat(value)
    if err != nil {
        return err
    }
    if stat.IsDir() {
        return fmt.Errorf("path does not represent a file: %s", value)
    }
    *f = append(*f, value)
    return nil
}