Merge pull request #548 from justincampbell/bash-substr

Add bash variable substring example

bash.html.markdown

@@ -46,6 +46,10 @@ echo '$VARIABLE'
 echo ${VARIABLE/Some/A}
 # This will substitute the first occurance of "Some" with "A"
 
+# Substring from a variable
+echo ${VARIABLE:0:7}
+# This will return only the first 7 characters of the value
+
 # Default value for variable
 echo ${FOO:-"DefaultValueIfFOOIsMissingOrEmpty"}
 # This works for null (FOO=), empty string (FOO=""), zero (FOO=0) returns 0