On the paragraph explaining arithmetic expansion, Bash's user guide uncovers 2 different ways of evaluating an expression, the first one uses $((EXPRESSION)) and the second one uses $[EXPRESSION]. The two ways seem pretty similar as the only difference I have found is:$[EXPRESSION] will only calculate the result of EXPRESSION, and do no tests:Yet, I am intrigued because the same document recommends using $[EXPRESSION] rather than $((EXPRESSION)).Wherever possible, Bash users should try to use the syntax with square brackets:Why would you want that if less tests are being done?
Why should I use $[ EXPR ] instead of $(( EXPR ))?
bash
Duplication Question (with answer)https://stackoverflow.com/questions/2415724/bash-arithmetic-expression-vs-arithmetic-expressionThe manpage for bash v3.2.48 says:[...] The format for arithmetic expansion is: $((expression)) The old format $[expression] is deprecated and will be removed in upcoming versions of bash.So $[...] is old syntax that should not be used anymoreIn addition to that answer:http://manual.cream.org/index.cgi/bash.1#27Info relating to bash versions:Here is some info about bash man pages (its hard to find info on what version each one is referring to):OPs link:http://www.tldp.org/guides.htmlBash Guide for Beginners version:    1.11author: Machtelt Garrels, last update:    Dec 2008sth (74.6k rep) quoting bash v3.2.48from https://stackoverflow.com/questions/2415724/bash-arithmetic-expression-vs-arithmetic-expression)Note: More info about [] vs (()) here: http://lists.gnu.org/archive/html/bug-bash/2012-04/msg00033.htmla link I found:http://www.gnu.org/software/bash/manual/last updated August 22, 2012http://www.gnu.org/software/bash/manual/bash.html#Arithmetic-Expansion