doushan3511 2018-02-16 07:22
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无法在Go中将命令行分配给变量参数

Package used: gopkg.in/urfave/cli.v1

Code Snippet:

app.Action = func(c *cli.Context) error {

    author := "anonymous"
    filename := "Image"
    if c.NArg() > 0 {
        author = c.Args().Get(1)
        filename = c.Args().Get(2)
    }
}

I call a function which uses author and filename after the if statement but the result is that author and filename have their initial values(anonymous and Image) and not the ones from the command line arguments using the function as shown above.

I am fairly new to go and looked into the documentation of the package and cannot find a solution.

And if i do this:

author:=c.Args().Get(1)
filename:=c.Args().Get(2)

then the function returns blank strings and they get initialized to both variables

and the command I am giving is something like this:

terminal -q "hi" -a "Eklavya" -f "Eklavya"
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  • dongyan1548 2018-02-16 08:24
    关注

    Your code is a bit incomplete, but you have probably defined the flags q, a and f.

    c.Args().Get() works only on args that are not passed as a flag. e.g. the call

    terminal hi Eklavya Eklavya
    

    has the args 0, 1 and 2 defined.

    To access the flags other funcs have to be used. The following change works:

    app.Action = func(c *cli.Context) error {
    
        author := "anonymous"
        filename := "Image"
        if len(c.GlobalFlagNames()) > 0 {
            author = c.String("a")
            filename = c.String("f")
        }
    }
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
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