diff --git a/_scripts/auto_save.sh b/_scripts/auto_save.sh
index bbe29e0..e991b80 100755
--- a/_scripts/auto_save.sh
+++ b/_scripts/auto_save.sh
@@ -1,9 +1,12 @@
 #!/bin/bash
 
-# This script runs as a cron job in half-hour intervals to automatically commit changes to the remote repository
+# This script automatically commits/pull changes to the remote repository with a generic commit message.
 
-NOTES_PATH="${HOME}/repos/computer_science"
-SPACE_TO_UNDERSCORE="${HOME}/repos/bash_scripts/space_to_underscore_filename.sh"
+# It is aliased to `cs-update` in .zshrc
+
+NOTES_PATH="/home/thomas/repos/computer_science"
+SPACE_TO_UNDERSCORE="/home/thomas/repos/computer_science/_scripts/space_to_underscore_filename.sh"
+CLEAN_IMAGE_DIRECTORY="/home/thomas/repos/computer_science/_scripts/clean_image_directory.sh"
 
 cd "$NOTES_PATH"
 
diff --git a/_scripts/random_revision_topic.sh b/_scripts/random_revision_topic.sh
index 079c364..2ebb32d 100755
--- a/_scripts/random_revision_topic.sh
+++ b/_scripts/random_revision_topic.sh
@@ -2,6 +2,8 @@
 
 # This script returns a random topic for me to revise
 
+# It is aliased to cs-revise in .zshrc
+
 # Choose source directories...
 DIRS_TO_PARSE="../Computer_Architecture ../Databases ../Electronics_and_Hardware ../Operating_Systems ../Programming_Languages/Shell ../Logic"
 
diff --git a/_scripts/space_to_underscore_filename.sh b/_scripts/space_to_underscore_filename.sh
new file mode 100755
index 0000000..e9fc4e5
--- /dev/null
+++ b/_scripts/space_to_underscore_filename.sh
@@ -0,0 +1,20 @@
+#!/bin/bash
+
+# Convert spaces in file and directory names to underscore
+
+main() {
+    find . -depth -name '* *' | while read fname; do
+        new_fname=$(echo $fname | tr " " "_")
+        if [ -e $new_fname ]; then
+            echo "File $new_fname already exists. Not replacing $fname"
+        else
+            echo "Creating new file $new_fname to replace $fname"
+            mv "$fname" $new_fname
+        fi
+    done
+}
+
+# Run and pipe errors and feedback to logfile
+
+&>/dev/null
+main