shell: added renaming recursively

wiki/linux/shell.md

@@ -24,6 +24,30 @@ The following is a list of Unix shells that are POSIX compliant.
 This section addresses various different functions by and actions that can be
 taken with shell commands.
 
+### Renaming Files
+
+Files can be renamed by using the `mv` command like in the following example.
+
+```sh
+mv old_name.ext new_name.ext
+```
+
+Another way to rename files that is especially useful if renaming a lot of files is needed is done
+by using the command-line utility `rename`.
+In the following example the string `string1` will be substituted by `string2` for a given file
+`file.ext`.
+
+```sh
+rename 's/string1/string2/g' file.ext
+```
+
+Additionally `find` can be used to recursively substitute substrings in all files inside a folder
+`folder` (including subfolders).
+
+```sh
+find folder -type f -exec rename 's/string1/string2/g' {} +
+```
+
 ### Expansion
 
 This section is based on the
@@ -136,4 +160,3 @@ Error outputs (stderr) can be silenced by appending `2> /dev/null`.
 The complete output of both stderr and stdout can be silenced by appending
 `> /dev/null 2>&1` to the command.
 A shortened version of it not possible on all shells is `&> /dev/null`.
-