Linux shell programming string compare syntax

Question

What is the difference between = and == to compare strings in Linux shell programming?

Maybe the following code works:

if [ \"$         


        

Answer 1

In general, the = operator works the same as == when comparing strings.

Note: The == comparison operator behaves differently within a double-brackets test than within single brackets.

[[ $a == z* ]]   # True if $a starts with an "z" (pattern matching).
[[ $a == "z*" ]] # True if $a is equal to z* (literal matching).

[ $a == z* ]     # File globbing and word splitting take place.
[ "$a" == "z*" ] # True if $a is equal to z* (literal matching).

source: http://tldp.org/LDP/abs/html/comparison-ops.html