golang: read cmd line arguments and additional parameters - go

Question

I am attempting to read the extra parameter passed to go build.go build example-service using the code below -
flag.Parse()
fmt.Println(flag.Args()) // Print "[build example-service]"
for _, cmd := range flag.Args() {
switch cmd {
case "build":
log.Println("build", cmd) // Print "build build"
}
}
I am successfully able to print flag.Args() as [build example-service] which is an array object
I unable to retrieve the example-service arg inside the switch case as cmd only prints build build

Answer 1

What you looking for is the "Command-Line Arguments" topic. More information: https://gobyexample.com/command-line-arguments
os package can use for this purpose. By os.Args array, exe file address (first index) and arguments (other indexes) are accessible.
Also to run your file using a command like this go run test.go arg1 arg2 arg3.... Here test.go is my test filename.
package main
import (
"fmt"
"os"
)
func main() {
fmt.Printf("Input args are %v and type is %T", os.Args, os.Args)
}
The output of this code after running the go run test.go build example-service command is something like this:
Input args are [...\test.exe build example-service] and type is []string
And your code can modified to:
for _, cmd := range os.Args {
switch cmd {
case "build":
log.Println("command: ", cmd)
case "example-service":
log.Println("command: ", cmd)
}
}