sort.go

// ChatGPT is going to take my job
package main

import (
	"bufio"
	"flag"
	"fmt"
	"os"
	"regexp"
	"sort"
	"strconv"
)

type sortableLine struct {
	key   string
	value string
}

type sortableLines []sortableLine

func toInt(s string) int {
	i, err := strconv.Atoi(s)
	if err != nil {
		fmt.Fprintln(os.Stderr, "Error converting to int:", err)
		os.Exit(1)
	}
	return i
}

func main() {
	// Parse command-line options
	regexStr := flag.String("regex", "", "Use regex to extract sort key")
	failOnNoMatch := flag.Bool("fail", false, "Fail if regex does not match")
	numericSort := flag.Bool("numeric", false, "Sort numerically")
	flag.Parse()

	// Compile the regex
	var regex *regexp.Regexp
	if *regexStr != "" {
		var err error
		regex, err = regexp.Compile(*regexStr)
		if err != nil {
			fmt.Fprintln(os.Stderr, "Error compiling regex:", err)
			os.Exit(1)
		}
	}

	// Read all the lines from stdin
	scanner := bufio.NewScanner(os.Stdin)
	lines := sortableLines{}
	for scanner.Scan() {
		line := scanner.Text()
		if regex != nil {
			// Extract the sort key from the line using the regex
			matches := regex.FindStringSubmatch(line)
			if matches == nil {
				if *failOnNoMatch {
					fmt.Fprintln(os.Stderr, "Regex did not match line:", line)
					os.Exit(1)
				}
				continue
			}
			switch len(matches) {
			case 1:
				lines = append(lines, sortableLine{key: line, value: line})
			case 2:
				lines = append(lines, sortableLine{key: matches[1], value: line})
			default:
				fmt.Fprintln(os.Stderr, "Regex matched more than one group:", line)
				os.Exit(1)
			}
		} else {
			lines = append(lines, sortableLine{key: line, value: line})
		}
	}
	if err := scanner.Err(); err != nil {
		fmt.Fprintln(os.Stderr, "Error reading from stdin:", err)
		os.Exit(1)
	}

	if *numericSort {
		sort.Slice(lines, func(i, j int) bool {
			// convert the keys to integers
			// if they aren't valid ints; throw an error
			return toInt(lines[i].key) < toInt(lines[j].key)
		})
	} else {
		sort.Slice(lines, func(i, j int) bool {
			return lines[i].key < lines[j].key
		})
	}

	for _, line := range lines {
		fmt.Println(line.value)
	}
}