go文件运行不了 无法调用其他文件的包 试过很多方法都是这样 希望得到各位指点一下
1、使用 flag.Usage重新赋值, flag.Usage的类型是func(), 即一种无参数声明且无结果声明的函数类型
package main
import (
"os"
"flag"
"fmt"
)
var name string
func init() {
flag.StringVar(&name, "name", "everyone", "The greeting object.")
}
func main() {
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "Usage of %s:\n", "question")
flag.PrintDefaults()
}
flag.Parse()
fmt.Printf("Hello, %s!\n", name)
}
PS D:\GO\src\commad_src_file_test> go run .\command_src_file.go --help
Usage of question:
-name string
The greeting object. (default "everyone")
exit status 2
2、使用 flag.CommandLine
package main
import (
"os"
"flag"
"fmt"
)
var name string
func init() {
flag.StringVar(&name, "name", "everyone", "The greeting object.")
}
func main() {
flag.CommandLine = flag.NewFlagSet("", flag.ExitOnError)
flag.CommandLine.Usage = func() {
fmt.Fprintf(os.Stderr, "Usage of %s:\n", "question")
flag.PrintDefaults()
}
flag.Parse()
fmt.Printf("Hello, %s!\n", name)
}
运行结果
PS D:\GO\src\commad_src_file_test> go run .\command_src_file.go --help
Usage of question:
exit status 2
将 flag.CommandLine 代码改为
flag.CommandLine = flag.NewFlagSet("", flag.PanicOnError)
运行结果
PS D:\GO\src\commad_src_file_test> go run .\command_src_file.go --help
Usage of question:
panic: flag: help requested
goroutine 1 [running]:
flag.(*FlagSet).Parse(0xc0000440c0, 0xc000004430, 0x1, 0x1, 0xc0000401f0, 0xc0000440c0)
E:/Go/src/flag/flag.go:938 +0x107
flag.Parse()
E:/Go/src/flag/flag.go:953 +0x76
main.main()
D:/GO/src/commad_src_file_test/command_src_file.go:25 +0x74
exit status 2
flag.ExitOnError含义是,告诉命令参数容器,当命令后跟–help或者参数设置的不正确的时候,在打印命令参数使用说明后以状态码2结束当前程序。
状态码2代表用户错误地使用了命令,而flag.PanicOnError与之的区别是在最后抛出“运行时恐慌(panic)”。
还可以使用这种方式,更灵活
package main
import (
"os"
"flag"
"fmt"
)
var name string
var cmdLine = flag.NewFlagSet("question", flag.ExitOnError)
func init() {
cmdLine.StringVar(&name, "name", "everyone", "The greeting object.")
}
func main() {
cmdLine.Parse(os.Args[1:]) // 给定的命令参数
fmt.Printf("Hello, %s!\n", name)
}