bugs fixed

.vscode/launch.json

@@ -11,7 +11,7 @@
             "mode": "auto",
             "program": "${fileDirname}",
             "env": {},
-            "args": ["--delete_archived","1"],
+            "args": ["-withArchiveAttr","-config","./testdata/config.json", "-dryrun"],
             "cwd": "${fileDirname}"
         }
     ]

DeleteArchivedBackups.go

@@ -1,7 +1,7 @@
 package main
 
 import (
-	"dblist"
+	"dblist/v2"
 	"flag"
 	"log"
 	"os"
@@ -18,57 +18,95 @@ func main() {
 	// {"path":"g:/ShebB", "Filename":"buh_prom8", "Days":1},
 	// ]
 
-	delArchived := flag.Bool("delete_archived", false, "deletes files with attribute archived set")
+	delArchived := flag.Bool("withArchiveAttr", false, "deletes files with attribute archived set")
 	configfile := flag.String("config", "", "full config file name (lists databases files groups)")
+	dryRun := flag.Bool("dryrun", false, "dry run (doesn't actually delete files)")
+	keepLastNcopies := flag.Uint("keeplastN", 2, "keep recent N copies")
+
 	flag.Parse()
 	if *configfile == "" {
 		flag.Usage()
 		os.Exit(1)
 	}
-	conf := dblist.ReadConfig(*configfile)
+	conf, err := dblist.ReadConfig(*configfile)
+	if err != nil {
+		log.Printf("Config file read error: %s", err)
+		return
+	}
+	// sort conf by databases names to allow sort.Search by database name
+	sort.Slice(conf, func(i, j int) bool {
+		if conf[i].Filename < conf[j].Filename {
+			return true
+		}
+		return false
+	})
 
+	// collect unique suffixes
+	suffixes := make(map[string]int)
+	for _, val := range conf {
+		if _, has := suffixes[val.Suffix]; !has {
+			suffixes[val.Suffix] = 0
+		}
+
+	}
+	// transform a map into slice
+	uniquesuffixes := make([]string, 0, len(suffixes))
+	for suf := range suffixes {
+		uniquesuffixes = append(uniquesuffixes, suf)
+	}
+	// gets unique folders names
 	unique := dblist.GetUniquePaths(conf)
 
+	// get files of each folder
 	files := dblist.ReadFilesFromPaths(unique)
 
 	lastfilesmap := make(map[string][]dblist.FileInfoWin)
 
-	if *delArchived {
-		for dir, slice := range files {
-			lastfilesslice := dblist.GetLastFilesGroupedByFunc(slice, dblist.GroupFunc)
-			// make lastfilesslice descending to use sort.Search
-			sort.Slice(lastfilesslice, func(i, j int) bool {
-				return lastfilesslice[i].Name() > lastfilesslice[j].Name() //DESC
-			})
-			lastfilesmap[dir] = lastfilesslice
-		}
-		deleteArchivedFiles(files, lastfilesmap)
-	} else {
-		flag.Usage()
+	// We append to dontDeleteLastbackupfiles files that should not be deleted: last files and file that have no config line for them.
+	for dir, filesindir := range files {
+		// We get most recent files. The will not be deleted.
+		dontDeleteLastbackupfiles := dblist.GetLastFilesGroupedByFunc(filesindir, dblist.GroupFunc, uniquesuffixes, *keepLastNcopies)
+
+		notinConfigFile := dblist.GetFilesNotCoveredByConfigFile(filesindir, conf, dblist.GroupFunc, uniquesuffixes)
+
+		// some actual files may not be in config file
+		dontDeleteLastbackupfiles = append(dontDeleteLastbackupfiles, notinConfigFile...)
+
+		// sort dontDeleteLastbackupfiles descending to use sort.Search later.
+		// We exploite descending order to find most recent backup files.
+		sort.Slice(dontDeleteLastbackupfiles, func(i, j int) bool {
+			return dontDeleteLastbackupfiles[i].Name() > dontDeleteLastbackupfiles[j].Name() //DESC
+		})
+		lastfilesmap[dir] = dontDeleteLastbackupfiles
 	}
+	deleteArchivedFiles(files, lastfilesmap, *delArchived, *dryRun)
 
 }
 
-// deleteArchivedFiles needs exceptfiles be sorted descending
-func deleteArchivedFiles(files, exceptfiles map[string][]dblist.FileInfoWin) {
+// deleteArchivedFiles needs exceptfiles to be sorted descending.
+// Exceptfiles sorted descending because it was used to get most recent backup file name earlier in the code.
+func deleteArchivedFiles(files, exceptfiles map[string][]dblist.FileInfoWin, delArchived, dryrun bool) {
 	for dir, slice := range files { // for every dir
 		for _, finf := range slice { // for every file in dir
 			if !finf.IsDir() { // dont touch subdirs and not archived
-				if (finf.WinAttr & syscall.FILE_ATTRIBUTE_ARCHIVE) == 0 { // no ARCHIVE means file has been archived
+				// No ARCHIVE atrribute means that file has been archived or copied somewhere.
+				// If file has Archive attribute you need a flag delArchived == true
+				if (finf.WinAttr&syscall.FILE_ATTRIBUTE_ARCHIVE) == 0 ||
+					delArchived { // or you insist on deleting files with Archive attr set
 
-					// search if file in question is in the exception list
-					curmap := exceptfiles[dir]                         // exceptfiles is descending
-					pos := sort.Search(len(curmap), func(i int) bool { // bin search
+					// search if current file is in the exception list
+					curmap := exceptfiles[dir]                         // exceptfiles is already sorted descending
+					pos := sort.Search(len(curmap), func(i int) bool { // we use bin search
 						return curmap[i].Name() <= finf.Name() // <= for the descending slice
 
 					})
 					if pos < len(curmap) && curmap[pos].Name() == finf.Name() {
 						// found
-						continue // file should not be deleted. this is the last file in the group
+						continue // file should not be deleted. this is the last file in the group of backup files
 					}
 					fullFilename := filepath.Join(dir, finf.Name())
-					log.Printf("deleting file %s\n", fullFilename)
-					if true { //DEBUG
+					log.Printf("rm %s\n", fullFilename)
+					if !dryrun {
 						err := os.Remove(fullFilename)
 						if err != nil {
 							log.Printf("%s\n", err)

README.md

@@ -0,0 +1,10 @@
+## A DBA backup files tool set. ##
+
+The utility DeleteArchivedBackups is used in databases backups operations.
+Sometimes a DBA needs to keep a directory with different backup files rotated.
+That is when a DBA needs to delete marked backup files. Or when one needs to deleted all but serveral last files.
+
+Files must obey naming scheme.
+Database name in file name and file suffix define a file group.
+Every file group may have its most recent files and outdated files.
+DeleteArchivedBackups deals with this task.

testdata/config.json

@@ -0,0 +1,7 @@
+[
+{"path":"j:/b", "Filename":"BC_Cold",             "suffix":"-differ.dif","Days":1},
+{"path":"j:/b", "Filename":"нашипост",          "suffix":"-FULL.bak","Days":5},
+{"path":"j:/b", "Filename":"from_84_Dirs", "suffix":".rar","Days":7},
+{"path":"g:/Shebb", "Filename":"buh_canvest",             "suffix":"-differ.rar","Days":1},
+{"path":"g:/Shebb", "Filename":"buh_canvest",             "suffix":"-FULL.rar","Days":1}
+]