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