From 9080b45d44383b08fb6b58d3bcefa2b758faa373 Mon Sep 17 00:00:00 2001
From: Aleteoryx <alyx@aleteoryx.me>
Date: Sun, 23 Feb 2025 23:11:06 -0500
Subject: [PATCH] readme, fixes

---
 README.md     | 23 +++++++++++++++++++++++
 backupper.tcl |  4 ++--
 2 files changed, 25 insertions(+), 2 deletions(-)
 create mode 100644 README.md

diff --git a/README.md b/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..2893fed6cfe3084b18d9f2f4f861d9bb995f8c2e
--- /dev/null
+++ b/README.md
@@ -0,0 +1,23 @@
+# Backupper
+
+a compressing deduplicating snapshot backup system, written in Tcl.
+
+- dependencies:
+  - sqlite3
+  - tcllib
+
+the script expects a linux environment, as it reads `/proc/cpuinfo` to get the number of cores. I believe there are no other platform-specific behaviors, so patching this script for windows or other unices would be trivial.
+
+to use it
+
+1. `backupper.tcl init <store>` some store directory. this is where backup data will go. backupper does not care what or where this directory is as long as it has read/write.
+2. `backupper.tcl importtar <store> <name> <tarball>` a tarball. the file data inside of it will be extracted and deduplicated, and the tarball itself will be stored with an id and hash.
+3. `backupper.tcl export <store> <id>` the id from step 2. the tarball will be replicated identically in the current directory, with file data restored
+
+there is also a simpler `importlist` command that takes in a list of files, one per line, and works similarly. on export, they will be placed in a local directory.
+
+there are also commands for inspecting the contents of the store, run the script with no args for more info.
+
+to list the backups in a store, run `sqlite3 -box <store>/index.db 'select rowid, * from tarballs'`. at some point I might add a command for this.
+
+GLHF don't sue me if this fails spectacularly
diff --git a/backupper.tcl b/backupper.tcl
index 7c698814729dc5289a0c4b7ccfca40a8d98ba677..5d5f01b268bd676062e5d63c882cbd0965900ce8 100755
--- a/backupper.tcl
+++ b/backupper.tcl
@@ -325,7 +325,7 @@ switch -- $command {
       append result [::tar::fmtrec [tpool::get $pool $job]]
     }
 
-    append result [binary format a[expr {16384 - ([string length $result] % 16384) + 512}] ""]
+    append result [binary format a[expr {16384 - ([string length $result] % 16384)}] ""]
 
     set ref [writestore $arpath $result 1]
     set date [clock seconds]
@@ -391,7 +391,7 @@ switch -- $command {
           tpool::wait $pool $job
           puts -nonewline $exportfd [::tar::fmtrec [tpool::get $pool $job]]
         }
-        puts -nonewline $exportfd [binary format a[expr {16384 - ([tell $exportfd] % 16384) + 512}] ""]
+        puts -nonewline $exportfd [binary format a[expr {16384 - ([tell $exportfd] % 16384)}] ""]
 
         close $exportfd
       }