如何在Go中访问命令行参数?它们不会作为参数传递给main
。
一个完整的程序(可能是通过链接多个包创建的)必须有一个名为main的包,其中包含一个函数
func main() { ... }
已定义。函数main.main()不接受任何参数,也不返回值。
发布于 2010-04-25 15:16:53
您可以使用os.Args
变量访问命令行参数。例如,
package main
import (
"fmt"
"os"
)
func main() {
fmt.Println(len(os.Args), os.Args)
}
您还可以使用flag package,它实现了命令行标志解析。
发布于 2016-12-03 06:53:20
Flag就是一个很好的包。
package main
// Go provides a `flag` package supporting basic
// command-line flag parsing. We'll use this package to
// implement our example command-line program.
import "flag"
import "fmt"
func main() {
// Basic flag declarations are available for string,
// integer, and boolean options. Here we declare a
// string flag `word` with a default value `"foo"`
// and a short description. This `flag.String` function
// returns a string pointer (not a string value);
// we'll see how to use this pointer below.
wordPtr := flag.String("word", "foo", "a string")
// This declares `numb` and `fork` flags, using a
// similar approach to the `word` flag.
numbPtr := flag.Int("numb", 42, "an int")
boolPtr := flag.Bool("fork", false, "a bool")
// It's also possible to declare an option that uses an
// existing var declared elsewhere in the program.
// Note that we need to pass in a pointer to the flag
// declaration function.
var svar string
flag.StringVar(&svar, "svar", "bar", "a string var")
// Once all flags are declared, call `flag.Parse()`
// to execute the command-line parsing.
flag.Parse()
// Here we'll just dump out the parsed options and
// any trailing positional arguments. Note that we
// need to dereference the pointers with e.g. `*wordPtr`
// to get the actual option values.
fmt.Println("word:", *wordPtr)
fmt.Println("numb:", *numbPtr)
fmt.Println("fork:", *boolPtr)
fmt.Println("svar:", svar)
fmt.Println("tail:", flag.Args())
}
https://stackoverflow.com/questions/2707434
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