Add a few keybindings

.zshrc

@@ -49,6 +49,30 @@ then
   exec tmux new-session -A -s 'auto'
 fi
 
+
+# History Substring Search bindings
+bindkey '^[[5~' history-substring-search-up
+bindkey '^[[6~' history-substring-search-down
+
+# Expands ... to ../..
+function expand-dot-to-parent-directory-path {
+  if [[ $LBUFFER = *.. ]]; then
+    LBUFFER+='/..'
+  else
+    LBUFFER+='.'
   fi
+}
+zle -N expand-dot-to-parent-directory-path
+bindkey -M emacs "." expand-dot-to-parent-directory-path
 
+# Inserts 'sudo ' at the beginning of the line.
+function prepend-sudo() {
+  if [[ "$BUFFER" != su(do|)\ * ]]; then
+    BUFFER="sudo $BUFFER"
+    (( CURSOR += 5 ))
+  fi
+}
+zle -N prepend-sudo
+bindkey "^X^S" prepend-sudo
 
+bindkey '^H' backward-kill-word