feat: add cmd/envtocsv for converting env files

cmd/envtocsv/go.mod

@@ -0,0 +1,5 @@
+module github.com/therootcompany/golib/cmd/envtocsv
+
+go 1.25.0
+
+require github.com/joho/godotenv v1.5.1

cmd/envtocsv/go.sum

@@ -0,0 +1,2 @@
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=

cmd/envtocsv/main.go

@@ -0,0 +1,138 @@
+// envtocsv - Converts one or more .env files into a merged, sorted CSV
+//
+// Authored in 2026 by AJ ONeal <aj@therootcompany.com> w/ Grok (https://grok.com).
+// To the extent possible under law, the author(s) have dedicated all copyright
+// and related and neighboring rights to this software to the public domain
+// worldwide. This software is distributed without any warranty.
+//
+// You should have received a copy of the CC0 Public Domain Dedication along with
+// this software. If not, see <https://creativecommons.org/publicdomain/zero/1.0/>.
+
+package main
+
+import (
+	"encoding/csv"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"slices"
+	"strings"
+
+	"github.com/joho/godotenv"
+)
+
+type MainConfig struct {
+	outputPath string
+	useTab     bool
+}
+
+func main() {
+	cfg := MainConfig{}
+
+	flag.StringVar(&cfg.outputPath, "o", "-", "output path ('-' = stdout)")
+	flag.BoolVar(&cfg.useTab, "tab", false, "use tab-delimited output instead of comma-separated")
+	flag.Parse()
+
+	files := flag.Args()
+	if len(files) == 0 {
+		files = []string{".env"}
+	}
+
+	multiFile := len(files) > 1
+
+	var allRows [][]string
+
+	for _, path := range files {
+		envMap, err := godotenv.Read(path)
+		if err != nil {
+			log.Printf("Warning: skipping %s: %v", path, err)
+			continue
+		}
+
+		rows := make([][]string, 0, len(envMap))
+		for k, v := range envMap {
+			if multiFile {
+				rows = append(rows, []string{k, v, path})
+			} else {
+				rows = append(rows, []string{k, v})
+			}
+		}
+
+		// Sort this file's rows by key
+		slices.SortFunc(rows, func(a, b []string) int {
+			return strings.Compare(a[0], b[0])
+		})
+
+		allRows = append(allRows, rows...)
+	}
+
+	if len(allRows) == 0 {
+		log.Println("No valid key-value pairs found in any input file")
+		return
+	}
+
+	// Deduplicate: keep the last occurrence of each key (override behavior)
+	seen := make(map[string]int) // key → index of latest occurrence
+	for i, row := range allRows {
+		seen[row[0]] = i
+	}
+
+	// Build final list (only the winning rows)
+	finalRows := make([][]string, 0, len(seen))
+	for _, idx := range seen {
+		finalRows = append(finalRows, allRows[idx])
+	}
+
+	// Final sort by key for stable, readable output
+	slices.SortFunc(finalRows, func(a, b []string) int {
+		return strings.Compare(a[0], b[0])
+	})
+
+	// Output writer setup
+	var w *csv.Writer
+	if cfg.outputPath == "-" {
+		w = csv.NewWriter(os.Stdout)
+	} else {
+		f, err := os.Create(cfg.outputPath)
+		if err != nil {
+			log.Fatalf("Failed to create output file %s: %v", cfg.outputPath, err)
+		}
+		defer f.Close()
+		w = csv.NewWriter(f)
+	}
+
+	// Configure delimiter based on -tab flag
+	if cfg.useTab {
+		w.Comma = '\t'
+		w.UseCRLF = false // keep LF even on Windows for consistency
+	} else {
+		w.Comma = ','
+	}
+
+	defer w.Flush()
+
+	// Header — conditional on multi-file
+	header := []string{"key", "value"}
+	if multiFile {
+		header = append(header, "source")
+	}
+	if err := w.Write(header); err != nil {
+		log.Fatalf("Failed to write header: %v", err)
+	}
+
+	// Write rows
+	for _, row := range finalRows {
+		if err := w.Write(row); err != nil {
+			log.Fatalf("Failed to write to %s: %v", cfg.outputPath, err)
+		}
+	}
+
+	if cfg.outputPath != "-" {
+		fmt.Fprintf(os.Stderr, "Wrote %d unique keys to %s (%s-delimited)\n",
+			len(finalRows), cfg.outputPath, map[bool]string{true: "tab", false: "comma"}[cfg.useTab])
+	} else {
+		fmt.Fprintf(os.Stderr, "(%d unique keys written to stdout, %s-delimited)\n",
+			len(finalRows), map[bool]string{true: "tab", false: "comma"}[cfg.useTab])
+	}
+}