Minor markup formatting change

Coding-style-guide.md

@@ -63,7 +63,7 @@ $PWD
 
 TODO: Add a list of all environment variables you can use.
 
-###If / Loop###
+###  If / For / While  ###
 
 Put `; do` and `; then` on the same line as the `while`, `for` or `if`.
 
@@ -109,7 +109,7 @@ local UPPERCASE=""
 UPPERCASE=""
 ```
 
-Variables name should not clobber command names, such as `dir` or `pwd`.
+Variable names should not clobber command names, such as `dir` or `pwd`.
 
 ```
 # Bad:
@@ -150,9 +150,7 @@ echo "global_var = $global_var"  # global_var = 37
 # Good:
 function func_good() {
   local local_var=""
-
   local_var=37
-
   echo $local_var
 }
 
@@ -165,7 +163,7 @@ global_var=$(func_good)
 echo "global_var = $global_var" # move function result to global scope
 ```
 
-In the next example, lots of global variables are used over and over again, but the script "unfortunately" works anyway. The `parse_json()` function does not even return a value and the two functions shares their variables. You could also write all this without any function; this would have the same effect.
+In the next example, lots of global variables are used over and over again, but the script "unfortunately" works anyway. The `parse_json()` function does not even return a value and the two functions share their variables. You could also write all this without any function; this would have the same effect.
 
 Bad-Example: with global variables
 ```
@@ -268,7 +266,7 @@ Constants and anything exported to the environment should be capitalized.
 # Constant
 readonly PATH_TO_FILES='/some/path'
 
-# Both constant and environment
+# Both constant and exported
 declare -xr ORACLE_SID='PROD'
 ```
 
@@ -374,27 +372,28 @@ function my_good_func() {
 }
 ```
 
-###Check return values###
+###  Return values  ###
 
-Always check return values and give informative return values.
+Always check return values and give informative error messages. For unpiped commands, use `$?` or check directly via an if statement to keep it simple. Use nonzero return values to indicate errors.
-
-For unpiped commands, use `$?` or check directly via an if statement to keep it simple.
 
 ```
 # Bad:
 mv "${file_list}" "${dest_dir}/"
 
+# Good:
+mv "${file_list}" "${dest_dir}/" || exit 1
+
 # Good:
 if ! mv "${file_list}" "${dest_dir}/"; then
   echo "Unable to move ${file_list} to ${dest_dir}" >&2
-  exit "${E_BAD_MOVE}"
+  exit 1
 fi
 
 # Good: use "$?" to get the last return value
 mv "${file_list}" "${dest_dir}/"
 if [[ "$?" -ne 0 ]]; then
   echo "Unable to move ${file_list} to ${dest_dir}" >&2
-  exit "${E_BAD_MOVE}"
+  exit 1
 fi
 ```
 
@@ -411,14 +410,14 @@ Nested backticks require escaping the inner ones with `\`. The `$(command)` form
 var="`command \`command1\``"
 
 # Good:
-var="$(command "$(command1)")"
+var="$(command \"$(command1)\")"
 ```
 
 ###  Eval  ###
 
 Eval is evil! Eval munges the input when used for assignment to variables and can set variables without making it possible to check what those variables were. Avoid `eval` if possible.
 
-##Sources##
+##  References  ##
 
 - [Shell Style Guide](https://google-styleguide.googlecode.com/svn/trunk/shell.xml)
 - [BASH Programming - Introduction HOW-TO](http://tldp.org/HOWTO/Bash-Prog-Intro-HOWTO.html)