From b3b0fc94f9782566977efdddd344f925c7f7522b Mon Sep 17 00:00:00 2001
From: Simon Ruderich <simon@ruderich.org>
Date: Sat, 15 Dec 2012 00:28:59 +0100
Subject: [PATCH] crontab.d: Add, directory for crontab snippets.

~/.crontab.d can be used by other configuration files (e.g. vim) to
provide crontab entries which are then loaded by `update.sh` in the
crontab entry of the current user.
---
 crontab.d/README    |  8 ++++
 crontab.d/update.sh | 90 +++++++++++++++++++++++++++++++++++++++++++++
 setup.sh            |  3 ++
 3 files changed, 101 insertions(+)
 create mode 100644 crontab.d/README
 create mode 100755 crontab.d/update.sh

diff --git a/crontab.d/README b/crontab.d/README
new file mode 100644
index 0000000..7017445
--- /dev/null
+++ b/crontab.d/README
@@ -0,0 +1,8 @@
+README
+======
+
+`update.sh` combines all 'crontab.*' files in this directory into a single
+crontab file and loads it with `crontab`.
+
+This replaces the current crontab! If no 'crontab.*' files were found, the
+current crontab is removed.
diff --git a/crontab.d/update.sh b/crontab.d/update.sh
new file mode 100755
index 0000000..cfdcbcc
--- /dev/null
+++ b/crontab.d/update.sh
@@ -0,0 +1,90 @@
+#!/bin/sh
+
+# Combine all crontab.* files in ~/.crontab.d/ into a single crontab file and
+# load it with `crontab`.
+#
+# An existing crontab entry not generated with this script is not overwritten.
+
+# Copyright (C) 2012  Simon Ruderich
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+set -e
+
+
+HEADER_WARNING="# WARNING! DO NOT EDIT THIS FILE! #"
+
+# Don't overwrite existing crontab entries.
+if crontab -l >/dev/null 2>&1; then
+    if crontab -l | head -n3 | grep "^$HEADER_WARNING$" >/dev/null; then
+        :
+    else
+        echo "Existing crontab entry found, please remove it manually."
+        exit 2
+    fi
+fi
+
+
+DIRECTORY="$HOME/.crontab.d"
+if test ! -d "$DIRECTORY" || test ! -O "$DIRECTORY"; then
+    exit 1
+fi
+
+CRONTAB=`mktemp --tmpdir="$DIRECTORY" update-crontab.XXXXXXXXXXXX`
+
+echo "###################################"  > "$CRONTAB"
+echo "$HEADER_WARNING"                     >> "$CRONTAB"
+echo "###################################" >> "$CRONTAB"
+echo >> "$CRONTAB"
+echo "# It was generated from '$DIRECTORY/*' on `date -R`." >> "$CRONTAB"
+
+
+NO_MATCHES=
+for file in "$DIRECTORY"/crontab.*; do
+    # No crontab.* files exist, abort.
+    if test ! -e "$file"; then
+        NO_MATCHES=y
+        break
+    fi
+
+    echo "Found '$file'."
+
+    echo             >> "$CRONTAB"
+    echo             >> "$CRONTAB"
+    echo "## $file:" >> "$CRONTAB"
+
+    START_REGEX='^# This [a-zA-Z]* is free software: you can redistribute it'
+    END_REGEX='^# along with this [a-zA-Z]*.  If not, see <[^>]*>\.'
+    < "$file" sed -e "/$START_REGEX/,/$END_REGEX/ d" \
+                  -e "/^#[ ]*$/ d" \
+                  -e "/^# Copyright (C) [0-9][0-9]* / d" \
+        | cat --squeeze-blank \
+        >> "$CRONTAB"
+done
+
+# Update crontab with the crontab.* files.
+if test -z "$NO_MATCHES"; then
+    echo
+    echo 'Updating crontab.'
+    crontab "$CRONTAB"
+
+# No files found, remove the existing crontab entry. Ignore errors in case no
+# crontab entry existed in the first place.
+else
+    echo 'No files found, removing old crontab (if it exists).'
+    crontab -r || true
+fi
+
+rm "$CRONTAB"
diff --git a/setup.sh b/setup.sh
index d8c00fd..adb2721 100755
--- a/setup.sh
+++ b/setup.sh
@@ -226,6 +226,9 @@ link zsh/rc ~/.zshrc
 link zsh/logout ~/.zlogout
 
 # Link setup for additional files.
+if installed crontab; then
+    link crontab.d ~/.crontab.d
+fi
 link lessfilter ~/.lessfilter
 if installed colordiff; then
     link colordiffrc ~/.colordiffrc
-- 
2.45.2