updatedb: Add mcron job and dedicated script

The script allows for centralizing the code into one place, instead of having it
in both Helm and mcron.

.config/cron/job.guile

@@ -13,5 +13,10 @@
        ;; (next-hour-from (next-day) (list (tm:hour (localtime (current-time)))))
        (+ (next-second) (- 86400 (- current-time currency-time))))))
  ;; A string is nicer than Scheme code for `mcron --schedule' output.
- ;; Other we could return '(system* "units_cur" currency-file)
+ ;; Otherwise we could return '(system* "units_cur" currency-file)
+ ;; and use job's 3rd argument as a description.
  (string-append "units_cur " currency-file))
+
+(job '(next-hour)
+     ;; '(next-hour '(3)) is broken in mcron 1.1.
+     "updatedb-local")

.emacs.d/lisp/init-helm.el

@@ -235,9 +235,10 @@ Requires `call-process-to-string' from `functions'."
   (let ((was-missing (not (file-exists-p db))))
     (when (or update was-missing)
       (if (= (shell-command
-              (funcall helm-locate-create-db-function
-                       db
-                       root))
+              (or  (executable-find "updatedb-local")
+                   (funcall helm-locate-create-db-function
+                            db
+                            root)))
              0)
           (message "locatedb file `%s' %s" db (if was-missing "created" "updated"))
         (error "Failed to %s locatedb file `%s'" (if was-missing "create" "update") db)))))

.local/bin/updatedb-local

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+update() {
+	[ $# -ne 2 ] && set -- "$1" "$1/locate.db"
+	echo >&2 "Updating '$2' database for '$1'..."
+	## From https://git.archlinux.org/svntogit/packages.git/tree/trunk/updatedb.conf?h=packages/mlocate.
+	updatedb -l 0 -o "$2" -U "$1" \
+		--prune-bind-mounts=1 \
+		--prunefs="9p afs anon_inodefs auto autofs bdev binfmt_misc cgroup cifs coda configfs cpuset cramfs debugfs devpts devtmpfs ecryptfs exofs ftpfs fuse fuse.encfs fuse.sshfs fusectl gfs gfs2 hugetlbfs inotifyfs iso9660 jffs2 lustre mqueue ncpfs nfs nfs4 nfsd pipefs proc ramfs rootfs rpc_pipefs securityfs selinuxfs sfs shfs smbfs sockfs sshfs sysfs tmpfs ubifs udf usbfs vboxsf" \
+		--prunepaths="/gnu/store /afs /mnt /net /sfs /tmp /udev /var/cache /var/lib/pacman/local /var/lock /var/run /var/spool /var/tmp" \
+		--prunenames=".git .hg .svn .cache Trash .Trash-$(id -u)"
+}
+
+update "/" "$HOME/.cache/locate.db"
+
+for i in "/run/media/$USER"/* "/media/$USER"/*; do
+	[ -d "$i" ] && update "$i"
+done
+
+if [ ! -d "/media/$USER" ]; then
+	for i in "/media/$USER"/*; do
+		[ -d "$i" ] && update "$i"
+	done
+fi
+