srvbackup

commit f45f4d38ebb7c0ea34092b3ce453db91fd73a927
parent 2b2f702327a35b07b7f60807153f709f30ab6dcc
Author: Jacob R. Edwards <jacob@jacobedwards.org>
Date:   Tue, 29 Oct 2024 11:44:11 -0700

Add support for excluding certain files

This adds a negation operator ('!') which excludes all paths beginning
with whatever follows the operator. This is useful if you want to
backup most files in a directory but want to exclude a few large,
redundant files.

One caveat of the implementation is that it treats a/b and a//b
differently.

Diffstat:
M
srvbackup
 | 
26
++++++++++++++++++++++++--

1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/srvbackup b/srvbackup
@@ -1,5 +1,5 @@
 #!/bin/sh
-# Copyright 2023 Jacob R. Edwards
+# Copyright 2023, 2024 Jacob R. Edwards
 # srvbackup, a server backup script
 #
 # This script is to be put on the server and is meant to be used
@@ -35,7 +35,29 @@ update() (
 	IFS='
 	'
 	cd /
-	pax -w -uf "$backup" $(sed '/^[ 	]*#/d' < /etc/backup/list)
+
+	matchfiles | pax -w -uf "$backup"
+)
+
+matchfiles() (
+	IFS='
+'
+	sed '/^!/d; /^[ 	]*#/d' < /etc/backup/list |
+		xargs -I% find % -type f -or -type d -and -empty |
+		awk 'BEGIN {
+			for (a in ARGV) {
+				argv[a] = ARGV[a]
+				delete ARGV[a]
+			}
+		}
+		{
+			for (a in argv) {
+				if (substr($0, 1, length(argv[a])) == argv[a]) {
+					next
+				}
+			}
+			print
+		}' $(sed -n '/^!/ s///p' < /etc/backup/list)
 )
 
 if test $# -eq 0; then