go get -u github.com/just-do-halee/opt@latest
| Examples | Latest Note |
type file string
type Textify struct {
Input opt.Argument[file] `msg:"Input path"`
Output opt.Option[file] `msg:"Output path" opt:"s,l"`
Verbose opt.Option[int] `msg:"Verbosity level -vv.." opt:"s,l,o"`
Silent opt.Option[bool] `msg:"Silent mode" opt:"s,l"`
Cat opt.Command[cat] `msg:"Print file contents"`
Help opt.Option[opt.Help] `opt:"s,l"`
HelpCommand opt.Command[opt.Help] `rename:"help"`
}
func (o *Textify) Before() error {
o.Output.Set("./output.txt")
o.Verbose.Set(2)
o.Silent.Set(false)
return nil
}
func (o *Textify) After() error {
var err error
err = o.Input.Validate(opt.IsFile[file])
if err != nil {
return err
}
err = o.Verbose.Validate(opt.IsMinMax(0, 3))
if err != nil {
return err
}
return nil
}
func (o *Textify) Run() error {
input := o.Input.Get()
output := o.Output.Get()
verbose := o.Verbose.Get()
silent := o.Silent.Get()
if verbose > 0 && !silent {
log.Println("Copying file:", input, "to", output)
}
bytesRead, err := ioutil.ReadFile(string(input))
if err != nil {
return err
}
err = ioutil.WriteFile(string(output), bytesRead, 0644)
if err != nil {
return err
}
return nil
}
// ----------------------------------------------
type cat struct {
Parent opt.Parent[Textify]
File opt.Argument[file] `msg:"File to print"`
Len opt.Option[uint] `msg:"Length of output" opt:"s,l"`
}
func (o *cat) Before() error {
o.Len.Set(10)
return nil
}
func (o *cat) After() error {
return o.File.Validate(opt.IsFile[file])
}
func (o *cat) Run() error {
p := o.Parent.Get()
verbose := p.Verbose.Get()
silent := p.Silent.Get()
println := func(a ...any) {
if verbose > 0 && !silent {
log.Println(a...)
}
}
file := o.File.Get()
println("Opening file:", file)
f, err := os.OpenFile(string(file), os.O_RDONLY, 0)
if err != nil {
return err
}
defer f.Close()
println("<---------Reading contents--------->")
// print file contents
buf := bufio.NewReader(f)
for i := uint(0); i < o.Len.Get(); i++ {
line, err := buf.ReadString('\n')
if err != nil {
break
}
fmt.Print(line)
}
println(">---------End of contents----------<")
return nil
}func main() {
err :=
opt.Args().
Version("v0.1.0").
Author("just-do-halee <just.do.halee@gmail.com>").
About("This is a CLI app program.").
Build(new(Textify))
if err != nil {
fmt.Print(err)
}
}