diff --git a/document/linux/config/bash/module/git.sh b/document/linux/config/bash/module/git.sh
index 42d10ce..bd9aaf1 100644
--- a/document/linux/config/bash/module/git.sh
+++ b/document/linux/config/bash/module/git.sh
@@ -45,3 +45,19 @@ gr()
     git rebase -i HEAD~${base}
   fi
 }
+
+# specify git user.
+# usage: gu [NAME] [EMAIL]
+gu()
+{
+  local name="${1}"
+  local email="${2}"
+
+  if [[ "${name}" = "" || "${email}" = "" ]]; then
+    echo "usage: gu [NAME] [EMAIL]"
+    return 1
+  fi
+
+  git config user.name "${name}"
+  git config user.email "${email}"
+}