added section on mutlitarget paths

docs/bash.md

@@ -1,6 +1,14 @@
 # bash
 
-## shortcut list
+- [bash](#bash)
+  - [shortcuts](#shortcuts)
+    - [list of shortcuts](#list-of-shortcuts)
+    - [unbind shortcuts](#unbind-shortcuts)
+  - [tips and tricks](#tips-and-tricks)
+    - [multitarget paths](#multitarget-paths)
+
+## shortcuts
+### list of shortcuts
 | Shortcut   | Action |
 | :--------- | :----- |
 | ctrl+a     | go to the start of the line |
@@ -9,9 +17,9 @@
 | ctrl+f     | move one character forwards |
 | alt+b      | move one word backwards |
 | alt+f      | move one word forwards |
-| **ctrl+w** | delete to last white space |
+| **ctrl+w** | **delete to last white space** |
 | alt+?      | show completion options |
-| **ctrl+r** | search command history backwards |
+| **ctrl+r** | **search command history backwards** |
 | ctrl+g     | exit history search |
 | ctrl+p     | previous command in history |
 | ctrl+n     | next command in history |
@@ -21,9 +29,9 @@
 | ctrl+q     | resume output to screen |
 | ctrl+c     | terminate command |
 | ctrl+z     | suspend current command (resume with `fg`) |
-| **ctrl+d** | exit shell |
+| **ctrl+d** | **exit shell** |
 
-## unbind shortcuts
+### unbind shortcuts
 bash shortcuts can be disabled with the following command in `.bashrc`/`.bash_profile`:
 ```bash
 bind -r "<shortcut-to-unbind>"
@@ -33,3 +41,22 @@ Example:
 bind -r "\C-h"
 ```
 `\C` is CTRL, `\M` is ALT
+
+## tips and tricks
+
+### multitarget paths
+
+Bash allows for variable expansion in paths. This can be useful, for example when copying multiple files from a directory. Instead of typing out the path multiple times, one can use '{<>,<>}' to specify multiple targets:
+```bash
+# without multitarget expansion
+cp foo/bar/moo.wav foo/bar/bark.wav foo/
+
+# with multitarget expansion
+cp foo/bar/{moo.wav,bark.wav} foo/
+
+# or even
+cp foo/bar/{moo,bark}.wav foo/
+```
+Multitarget expansion also works in the middle of a path as seen in the third command example above.
+> Use only ',' to separate targets and **no whitespace** as that would make a new argument.
+> The expansion makes a new argument for each entry inside the braces, so **copy to several targets does not work.**