How come when x=abc, [[ $x > 123 ]] && echo yes || echo no returns yes?

Question

I understand that it is a string comparison, however i dont understand how "abc" & "123" are compared against each other. Thanks in advance!

see http://stackoverflow.com/questions/11989373/bash-testing-if-a-string-is-greater-than-another-how-does-it-work-internal — zeppelin, Feb 11 '17 at 21:55
The strings are compared against each other lexicographically — look up what that means. — G-Man Says 'Reinstate Monica', Feb 11 '17 at 22:27

score 7 · Accepted Answer · edited Feb 12 '17 at 01:35

That's because, inside [[…]], the operators < and > do string comparison.

In doing an string comparison the order is given (basically) by the alphabet, where a is before (smaller) than b and smaller than c: a < b < c.
Numbers are usually before (smaller) than letters: 1 < 2 < a

So, as an a sorts after a 1 abc is greater than 123:

$ [[ abc > 123 ]] && echo yes
yes

Or, as you present it:

$ x=abc    y=123
$ [[ $x > $y ]] && echo yes
yes

How come when x=abc, [[ $x > 123 ]] && echo yes || echo no returns yes?

1 Answers1