From cec157912e92edc3e4d5323818b6b562d5c9e159 Mon Sep 17 00:00:00 2001
From: Colin Patrick Mccabe <cmccabe@alumni.cmu.edu>
Date: Sun, 21 Aug 2016 15:17:45 -0700
Subject: [PATCH] Add directory_merge.go

---
 .gitignore         |    1 +
 directory_merge.go |   95 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+), 0 deletions(-)
 create mode 100644 directory_merge.go

diff --git a/.gitignore b/.gitignore
index 6d9e56f..5c2abdc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,6 +13,7 @@ show_default_sockopts
 print-code-points
 hexconv
 msgpack-translate
+directory_merge
 
 #
 # Normal rules
diff --git a/directory_merge.go b/directory_merge.go
new file mode 100644
index 0000000..31af6fe
--- /dev/null
+++ b/directory_merge.go
@@ -0,0 +1,95 @@
+package main
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"math"
+	"os"
+	"strings"
+)
+
+func usage(retval int) {
+	fmt.Printf("directory_merge: moves files from multiple directories " +
+		"into a single directory\n");
+	fmt.Printf("usage: directory_merge [destination_directory] " +
+		"[source_dir 1] ... [source_dir N]\n")
+	os.Exit(retval)
+}
+
+type RenamePlan struct {
+	src string
+	dstIdx uint64
+}
+
+func (plan *RenamePlan) DstToString(numDigits int) string {
+	return fmt.Sprintf("%0" + fmt.Sprintf("%d", numDigits) + "d", plan.dstIdx);
+}
+
+func (plan *RenamePlan) String(dstDir string, numDigits int) string {
+	return plan.src + " -> " + dstDir + "/" + plan.DstToString(numDigits);
+}
+
+func (plan *RenamePlan) Execute(dstDir string, numDigits int) error {
+	dstFile := dstDir + "/" + plan.DstToString(numDigits)
+	fmt.Printf("Renaming %s to %s.\n", plan.src, dstFile)
+	err := os.Rename(plan.src, dstFile)
+	if err != nil {
+		return errors.New(fmt.Sprintf("Failed to rename %s to %s: %v\n",
+			plan.src, dstFile, err.Error()))
+	}
+	return nil
+}
+
+func main() {
+	if (len(os.Args) < 3) {
+		usage(1)
+	}
+	dstDir := os.Args[1]
+	srcDirs := os.Args[2:]
+	renamePlans := make([]*RenamePlan, 0)
+	var dstIdx uint64
+	for srcDirIdx := range srcDirs {
+		// ioutil.ReadDir alphabetizes what it returns
+		srcDir := srcDirs[srcDirIdx]
+		srcs, err := ioutil.ReadDir(srcDir)
+		if err != nil {
+			panic(fmt.Sprintf("Error reading directory %s: %s", srcDir, err))
+		}
+		for srcIdx := range srcs {
+			srcPath := srcDir + "/" + srcs[srcIdx].Name()
+			dstIdx++
+			renamePlan := &RenamePlan {
+				src: srcPath,
+				dstIdx: dstIdx,
+			}
+			renamePlans = append(renamePlans, renamePlan)
+		}
+	}
+	numDigits := int(math.Ceil(math.Log10(float64(dstIdx))))
+	for renamePlanIdx := range renamePlans {
+		fmt.Printf("%s\n", renamePlans[renamePlanIdx].
+								String(dstDir, numDigits));
+	}
+	reader := bufio.NewReader(os.Stdin)
+	for {
+		fmt.Printf("Execute? (y/n):\n")
+		text, _ := reader.ReadString('\n')
+		text = strings.TrimSpace(text)
+		if text == "y" {
+			break
+		}
+		if text == "n" {
+			fmt.Printf("Aborting.\n");
+			os.Exit(0)
+		}
+	}
+	for renamePlanIdx := range renamePlans {
+		err := renamePlans[renamePlanIdx].Execute(dstDir, numDigits);
+		if err != nil {
+			panic(err)
+		}
+	}
+	os.Exit(0)
+}
-- 
1.6.6.rc1.39.g9a42