英文:
Go Flag Usage Description Contains the Word value
问题
我已经定义了一个自定义标志，用于接受字符串切片，代码如下：
type strSliceFlag []string
func (i *strSliceFlag) String() string {
return fmt.Sprint(*i)
}
func (i *strSliceFlag) Set(value string) error {
*i = append(*i, value)
return nil
}
然后我使用以下代码进行解析：
...
var tags strSliceFlag
flag.Var(&tags, "t", tFlagExpl)
flag.Parse()
...
当我构建这个程序并使用帮助标志运行它时：main -h，它会打印出：
Usage of main:
-t value
Test explanation
我的问题是，value这个词是从哪里来的？我找不到如何删除它的方法。我认为这可能与标志的默认值有关。
英文:
I've defined a custom flag for accepting a slice of strings as such:
type strSliceFlag []string
func (i *strSliceFlag) String() string {
return fmt.Sprint(*i)
}
func (i *strSliceFlag) Set(value string) error {
*i = append(*i, value)
return nil
}
I then parse it with
...
var tags strSliceFlag
flag.Var(&tags, "t", tFlagExpl)
flag.Parse()
...
When I build this program, and run it with the help flag: main -h, it prints out:
Usage of main:
-t value
Test explanation
My question is, where is the word value coming from? I can't find out how to remove it. I think it maybe has something to do with the default value for the flag.
答案1
得分: 1
value是flag.UnquoteUsage为自定义类型选择的默认参数名称（通过flag.(*FlagSet).PrintDefaults呈现）。
您可以使用反引号覆盖默认值在您的用法文本中。反引号将从用法文本中删除。例如：
package main
import (
"flag"
"fmt"
)
type stringSlice []string
func (s *stringSlice) String() string {
return fmt.Sprint(*s)
}
func (s *stringSlice) Set(v string) error {
*s = append(*s, v)
return nil
}
func main() {
var s stringSlice
flag.Var(&s, "foo", "append a foo to the list")
flag.Var(&s, "foo2", "append a `foo` to the list")
flag.Parse()
}
使用-h运行将显示参数名称的更改：
Usage of ./flagusage:
-foo value
append a foo to the list
-foo2 foo
append a foo to the list
英文:
value is the default argument name chosen by flag.UnquoteUsage for custom types (rendered via flag.(*FlagSet).PrintDefaults).
You can override the default with backquotes in your usage text. The backquotes are stripped from usage text. Eg:
package main
import (
"flag"
"fmt"
)
type stringSlice []string
func (s *stringSlice) String() string {
return fmt.Sprint(*s)
}
func (s *stringSlice) Set(v string) error {
*s = append(*s, v)
return nil
}
func main() {
var s stringSlice
flag.Var(&s, "foo", "append a foo to the list")
flag.Var(&s, "foo2", "append a `foo` to the list")
flag.Parse()
}
Running with -h shows how the argument name changes:
Usage of ./flagusage:
-foo value
append a foo to the list
-foo2 foo
append a foo to the list
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