Add headings

Author: mattmc3

Diff for: content/posts/2020-09-17-zsh-splitting-a-string-into-an-array.md

@@ -5,21 +5,28 @@ categories = 'Guide'
 tags = ['Zsh', 'Shell']
 +++
 
+# Zsh - splitting a string into an array
+
+## Intro
+
 There are a ton of different ways to split up a string in Zsh. This post attempts to
 show them with examples to help you build your own. I write Zsh scripts all the time,
 and still reference back to this guide, so there you go.
 
+## Using the split parameter expansion `${(s/x/)foo}`
+
 From the Zsh docs on [Parameter Expansion
 Flags](https://zsh.sourceforge.io/Doc/Release/Expansion.html#Parameter-Expansion-Flags)
 (yeah - I know... how would anyone ever find that if they didn't know where to look!?)
 
-> j:string:  Join the words of arrays together using string as a separator. s:string:
-> Force field splitting at the separator string.
+> j:string:  Join the words of arrays together using string as a separator.
+>
+> s:string: Force field splitting at the separator string.
 
 You can also read more by running `man zshexpn`. (Again... I know, right!? How would
 anyone know to look there!?)
 
-Example splitting a string on slash character in Zsh.
+Example splitting a string on slash character in Zsh:
 
 ```zsh
 $ str=part1/part2/part3
@@ -30,6 +37,8 @@ $ echo ${#parts[@]}
 3
 ```
 
+## Using split with bracketed indexing `${foo[start,end]}`
+
 You can use split `${(@s:/:)str}` and indexing `[start,end]` to do more sophisticated
 surgery on string parts. Note that Zsh array indexing starts a 1, not 0.
 
@@ -48,7 +57,7 @@ sorin-ionescu/prezto
 [An example from the Zsh
 docs](https://zsh.sourceforge.io/Doc/Release/Expansion.html#Examples) which shows
 splitting. Note the use of slash below unlike the colon above to surround the split
-character - remember that symbol is swapable and doesn't change the behavior of the
+character - remember that symbol is swappable and doesn't change the behavior of the
 split at all:
 
 ```zsh
@@ -59,7 +68,7 @@ a
 1
 ```
 
-Getting the first 2 parts
+Getting the first 2 parts:
 
 ```zsh
 $ str=a/b/c/d/e/f
@@ -68,6 +77,8 @@ $ echo ${(@j:/:)parts[1,2]}
 a/b
 ```
 
+## Pattern removal with `#` and `%`
+
 You can also use `#` and `%` parameter expansion symbols: [see
 docs](http://zsh.sourceforge.net/Doc/Release/Expansion.html#Parameter-Expansion). `#`
 removes from the left side, and `%` from the right, which I remember by the fact that
@@ -88,7 +99,11 @@ $ echo ${str##*/}
 part3
 ```
 
-Word splitting is done with the '=' character:
+## Word splitting
+
+Word splitting is done for every command you type to split out arguments. You can use
+those same Zsh word splitting rules for your own splits if you are splitting on
+whitespace. This is done with the '=' character:
 
 ```zsh
 $ sentence="ls -l -A -h"
@@ -100,5 +115,7 @@ ls
 -h
 ```
 
+## Conclusion
+
 Hope this is a helpful reference. There's [also a gist that I keep up-to-date as well
 here](https://gist.github.com/mattmc3/76ad634f362b5a9a54f1779a4737d5ae).