(git) log for file/directory

git.md

@@ -12,14 +12,19 @@ findings.
   - [glossary](#glossary)
   - [branches](#branches)
     - [create a branch](#create-a-branch)
+    - [delete a branch](#delete-a-branch)
   - [submodules](#submodules)
+    - [update reference](#update-reference)
+  - [show only names of changed files on `show` or `diff`](#show-only-names-of-changed-files-on-show-or-diff)
   - [stash](#stash)
   - [fixup](#fixup)
   - [removing files from the index](#removing-files-from-the-index)
+  - [list commits that changed a file or directory](#list-commits-that-changed-a-file-or-directory)
   - [philosophies](#philosophies)
     - [merge](#merge)
     - [rebase](#rebase)
   - [squash](#squash)
+  - [tags](#tags)
 <!--toc:end-->
 
 
@@ -128,6 +133,26 @@ git rm --cached <file-name>
 This is helpful if one accidentally committed autogenerated files.
 
 
+## log for file or directory
+
+To show the commits that changed a file use
+
+```sh
+git log --follow <filename>
+```
+
+For a directory use
+
+```sh
+git log <path>
+```
+
+The latter struggles when a files was renamed, so for specific files
+it is recommended to use the first command.
+For directories, or when sure that the file was not renamed, the
+second command is easier.
+
+
 ## philosophies
 
 Important things to always remember: