Merged pull request #308 from juanghurtado/master.

New prompt methods on Git lib file

lib/git.zsh

@@ -4,6 +4,7 @@ function git_prompt_info() {
   echo "$ZSH_THEME_GIT_PROMPT_PREFIX${ref#refs/heads/}$(parse_git_dirty)$ZSH_THEME_GIT_PROMPT_SUFFIX"
 }
 
+# Checks if working tree is dirty
 parse_git_dirty() {
   if [[ -n $(git status -s 2> /dev/null) ]]; then
     echo "$ZSH_THEME_GIT_PROMPT_DIRTY"
@@ -12,7 +13,24 @@ parse_git_dirty () {
   fi
 }
 
-# get the status of the working tree
+# Checks if there are commits ahead from remote
+function git_prompt_ahead() {
+  if $(echo "$(git log origin/master..HEAD 2> /dev/null)" | grep '^commit' &> /dev/null); then
+    echo "$ZSH_THEME_GIT_PROMPT_AHEAD"
+  fi
+}
+
+# Formats prompt string for current git commit short SHA
+function git_prompt_short_sha() {
+  SHA=$(git rev-parse --short HEAD 2> /dev/null) && echo "$ZSH_THEME_GIT_PROMPT_SHA_BEFORE$SHA$ZSH_THEME_GIT_PROMPT_SHA_AFTER"
+}
+
+# Formats prompt string for current git commit long SHA
+function git_prompt_long_sha() {
+  SHA=$(git rev-parse HEAD 2> /dev/null) && echo "$ZSH_THEME_GIT_PROMPT_SHA_BEFORE$SHA$ZSH_THEME_GIT_PROMPT_SHA_AFTER"
+}
+
+# Get the status of the working tree
 git_prompt_status() {
   INDEX=$(git status --porcelain 2> /dev/null)
   STATUS=""