Backup support

internal/buffer/backup.go

@@ -2,19 +2,51 @@ package buffer
 
 import (
 	"io"
+	"log"
+	"os"
+	"time"
 
 	"github.com/zyedidia/micro/internal/config"
 	"github.com/zyedidia/micro/internal/util"
 	"golang.org/x/text/encoding"
 )
 
+const backupMsg = `A backup was detected for this file. This likely means that micro
+crashed while editing this file, or another instance of micro is currently
+editing this file.
+
+The backup was created at %s.
+
+* 'recover' will apply the backup as unsaved changes to the current buffer.
+  When the buffer is closed, the backup will be removed.
+* 'ignore' will ignore the backup, discarding its changes. The backup file
+  will be removed.
+
+Options: [r]ecover, [i]gnore: `
+
 // Backup saves the current buffer to ConfigDir/backups
 func (b *Buffer) Backup() error {
 	if !b.Settings["backup"].(bool) {
 		return nil
 	}
 
-	name := config.ConfigDir + "/backups" + util.EscapePath(b.AbsPath)
+	sub := time.Now().Sub(b.lastbackup)
+	if sub < time.Duration(backup_time)*time.Millisecond {
+		log.Println("Backup event but not enough time has passed", sub)
+		return nil
+	}
+
+	b.lastbackup = time.Now()
+
+	backupdir := config.ConfigDir + "/backups/"
+	if _, err := os.Stat(backupdir); os.IsNotExist(err) {
+		os.Mkdir(backupdir, os.ModePerm)
+		log.Println("Creating backup dir")
+	}
+
+	name := backupdir + util.EscapePath(b.AbsPath)
+
+	log.Println("Backing up to", name)
 
 	err := overwriteFile(name, encoding.Nop, func(file io.Writer) (e error) {
 		if len(b.lines) == 0 {
@@ -43,6 +75,15 @@ func (b *Buffer) Backup() error {
 	return err
 }
 
+// RemoveBackup removes any backup file associated with this buffer
+func (b *Buffer) RemoveBackup() {
+	if !b.Settings["backup"].(bool) {
+		return
+	}
+	f := config.ConfigDir + "/backups/" + util.EscapePath(b.AbsPath)
+	os.Remove(f)
+}
+
 // ApplyBackup applies the corresponding backup file to this buffer (if one exists)
 func (b *Buffer) ApplyBackup() error {
 	return nil