I Wrote A CLI Tool Instead Of Doing The Thing

I needed to rename 12 files. Instead, I wrote a general-purpose file renaming CLI tool in Go with regex support, dry-run mode, and colorized output.

The Tool

package main

import (
    "flag"
    "fmt"
    "regexp"
    // 47 more imports
)

func main() {
    dryRun := flag.Bool("dry-run", false, "preview changes")
    pattern := flag.String("pattern", "", "regex pattern")
    recursive := flag.Bool("r", false, "recursive mode")
    verbose := flag.Bool("v", false, "verbose output")
    colors := flag.Bool("colors", true, "colorized output")
    // 12 more flags

    // 400 lines of immaculately structured code
}

The Task

# What I actually needed to do
for f in *.jpeg; do mv "$f" "${f%.jpeg}.jpg"; done

Time Investment

Activity	Time
Writing the CLI tool	4 hours
Adding tests	1 hour
Debating flag names	45 minutes
Actually renaming the files	5 minutes
Convincing myself it was worth it	ongoing

Was It Worth It?

The tool now lives in a private repo I’ll never open again. But it compiles to a single binary, so that’s something.

Next week I need to delete 3 log files. Time to write a log rotation daemon.