mirror of
https://github.com/vlang/v.git
synced 2023-08-10 21:13:21 +03:00
37 lines
1.3 KiB
Markdown
37 lines
1.3 KiB
Markdown
The `flag` module helps command-line flag parsing.
|
|
Main features are:
|
|
- parses flags like `-f` or '--flag' or '--stuff=things' or '--things stuff'.
|
|
- handles bool, int, float and string args.
|
|
- can print usage information listing all the declrared flags.
|
|
- handles unknown arguments as error.
|
|
|
|
Usage example:
|
|
|
|
```v
|
|
module main
|
|
|
|
import os
|
|
import flag
|
|
|
|
fn main() {
|
|
mut fp := flag.new_flag_parser(os.args)
|
|
fp.application('flag_example_tool')
|
|
fp.version('v0.0.1')
|
|
fp.limit_free_args(0, 0) // comment this, if you expect arbitrary texts after the options
|
|
fp.description('This tool is only designed to show how the flag lib is working')
|
|
fp.skip_executable()
|
|
an_int := fp.int('an_int', 0, 0o123, 'some int to define 0o123 is its default value')
|
|
a_bool := fp.bool('a_bool', 0, false, 'some boolean flag. --a_bool will set it to true.')
|
|
a_float := fp.float('a_float', 0, 1.0, 'some floating point value, by default 1.0 .')
|
|
a_string := fp.string('a_string', `a`, 'no text', 'finally, some text with ' +
|
|
' `-a` as an abbreviation, so you can pass --a_string abc or just -a abc')
|
|
additional_args := fp.finalize() or {
|
|
eprintln(err)
|
|
println(fp.usage())
|
|
return
|
|
}
|
|
println('an_int: $an_int | a_bool: $a_bool | a_float: $a_float | a_string: "$a_string" ')
|
|
println(additional_args.join_lines())
|
|
}
|
|
```
|