dedup

commit 367928d1742c6f7b12720e6c60a9292e6b708c7c
parent 34990ad2e3066a5fd23cebc22b997dff63ac272a
Author: sin <sin@2f30.org>
Date:   Wed, 21 Mar 2018 16:08:11 +0000

Add root dir option

Thanks lostd!

Diffstat:
M
README
 | 
18
+++++++++---------
M
dedup.c
 | 
12
++++++++++--

2 files changed, 19 insertions(+), 11 deletions(-)
diff --git a/README b/README
@@ -4,29 +4,29 @@ used in a pipeline with tar/gpg etc.
 dedup only handles a single file at a time, so using tar is advised.
 For example, to dedup a tar file you can invoke dedup as follows:
 
-    tar cf - ~/bak | dedup
+    tar cf - ~/bak | dedup -r ~/bak-dedup
 
-This will create .{cache,index,store} files in the current directory.
-The store file contains all the unique blocks.  The index file
-contains all the revisions of files that have been deduplicated.  Each
-revision is identified by its SHA256 hash.  The cache file is only
-used to speed up block comparison.
+This will create .{cache,index,store} files in the ~/bak-dedup
+directory.  The store file contains all the unique blocks.  The index
+file contains all the revisions of files that have been deduplicated.
+Each revision is identified by its SHA256 hash.  The cache file is
+only used to speed up block comparison.
 
 To list all known revisions run:
 
-    dedup -l
+    dedup -r ~/bak-dedup -l
 
 You will get a list of hashes.  Each hash corresponds to a single file
 (in this case, a tar archive).
 
 To extract a file from the deduplicated store run:
 
-    dedup -e <hash> > bak.tar
+    dedup -r ~/bak-dedup -e <hash> > bak.tar
 
 You can mix dedup with other programs like gpg(1).  For example to
 perform a remote backup you can use the following command:
 
-    tar cf - ~/bak | gpg -c | ssh user@host dedup
+    tar cf - ~/bak | gpg -c | ssh user@host dedup -r ~/bak-dedup
 
 Cheers,
 sin
diff --git a/dedup.c b/dedup.c
@@ -519,14 +519,14 @@ term(void)
 void
 usage(void)
 {
-	fprintf(stderr, "usage: %s [-clv] [-e id] [file]\n", argv0);
+	fprintf(stderr, "usage: %s [-clv] [-e id] [-r root] [file]\n", argv0);
 	exit(1);
 }
 
 int
 main(int argc, char *argv[])
 {
-	char *id = NULL;
+	char *id = NULL, *root = NULL;
 	int fd = -1, lflag = 0, cflag = 0;
 
 	ARGBEGIN {
@@ -539,6 +539,9 @@ main(int argc, char *argv[])
 	case 'l':
 		lflag = 1;
 		break;
+	case 'r':
+		root = EARGF(usage());
+		break;
 	case 'v':
 		verbose = 1;
 		break;
@@ -549,6 +552,11 @@ main(int argc, char *argv[])
 	if (argc > 1)
 		usage();
 
+	if (root != NULL) {
+		mkdir(root, 0700);
+		chdir(root);
+	}
+
 	init();
 
 	if (cflag) {