Go exec.Command() returns exit status 64

I was figuring out

> exec.Command()

In Go. It is straightforward and has no problem using primary terminal commands like "ls", "cat", etc...

But, when I wanted to use the output of the "log" command in macOS. It always returns an error.

Here is the simple usage of it:

func main() {
    out, err := exec.Command("log", "help").Output()
    if err != nil {
        log.Printf("error: %v", err)
    }

    fmt.Println(string(out))
}

And here is the error:

2022/11/19 20:03:37 error: exit status 64

I expected to see outputs of log help in macOS.

But, my program returns an error with exit status 64

Please let me know if there is anything I missed.

There's nothing wrong with your code, if you try the exact same command you're executing in terminal, and see the exit status, it will be 64:

➜  ~ log help
usage:
    log <command>

global options:
    -?, --help
    -q, --quiet
    -v, --verbose

commands:
    collect         gather system logs into a log archive
    config          view/change logging system settings
    erase           delete system logging data
    show            view/search system logs
    stream          watch live system logs
    stats           show system logging statistics

further help:
    log help <command>
    log help predicates

➜  ~ echo $?
64

And in case you're wondering why is it returning 64, you can ask sysexits for what it means:

➜  ~ man sysexits | grep -A 3 '64'
     EX_USAGE (64)         The command was used incorrectly, e.g., with the
                           wrong number of arguments, a bad flag, a bad syntax
                           in a parameter, or whatever.