Add an automatic backup restoration script that handles .kak.XXXXXX files

rc/autorestore.kak

@@ -0,0 +1,53 @@
+## If set to true, backups will be removed as soon as they have been restored
+decl bool autorestore_purge_restored true
+
+def -hidden _autorestore-restore-buffer %{
+    nop %sh{
+        buffer_basename="${kak_bufname##*/}"
+        buffer_dirname=$(dirname "${kak_bufname}")
+
+        ## Find the name of the latest backup created for the buffer that was open
+        latest_backup_path=$(find "${buffer_dirname}" -type f -readable -name ".${buffer_basename}.kak.*" -printf '%A@/%p\n' 2>/dev/null \
+                             | sort -n -t. -k1 | sed -nr 's/^.+\///;$p')
+        test ! -z "${latest_backup_path}" || exit
+
+        ## Replace the content of the buffer with the content of the backup file
+        echo "
+            exec -draft %{ %d!cat<space>${latest_backup_path}<ret>d }
+            echo -color Information Backup restored
+        "
+
+        ## If the backup file has to be removed, issue the command once
+        ## the current buffer has been saved
+        ## If the autorestore_purge_restored option has been unset right after the
+        ## buffer was restored, do not remove the backup
+        echo "
+            hook -group autorestore global BufWritePost (.+/)?${kak_bufname} %{
+                nop %sh{
+                    echo \"\${kak_opt_autorestore_purge_restored}\" > /tmp/out
+                    if [ \"\${kak_opt_autorestore_purge_restored,,}\" = yes \
+                         -o \"\${kak_opt_autorestore_purge_restored,,}\" = true ]; then
+                        rm -f '${latest_backup_path}'
+                    fi
+                }
+            }
+        "
+    }
+}
+
+## Remove all the backups that have been created for the current buffer
+def autorestore-purge-backups %{
+    nop %sh{
+        buffer_basename="${kak_bufname##*/}"
+        buffer_dirname=$(dirname "${kak_bufname}")
+
+        find "${buffer_dirname}" -type f -readable -name ".${buffer_basename}.kak.*" -delete 2>/dev/null
+    }
+}
+
+## If for some reason, backup files need to be ignored
+def autorestore-disable %{
+    rmhooks global autorestore
+}
+
+hook -group autorestore global BufCreate .* %{ _autorestore-restore-buffer }