On Sat, Mar 04, 2017 at 01:15:58PM +0100, Rob la Lau wrote: > Looking a bit further: it doesn't do any comparison on the given strings: > > $ [[ "x" -eq "y" ]] && echo "yes" || echo "no" > yes
You're misunderstanding. In a math context, which you are creating here by using -eq, the word 'x' is interpreted as a variable name, which may contain another variable name, and so on, until finally an integer is discovered. Same for the word 'y'. > $ [[ "x" -eq "yz" ]] && echo "yes" || echo "no" > yes Same for the word 'yz'. In your case, I suspect the variables x, y and yz are all undefined, which means they evaluate to 0. imadev:~$ unset x yz; if [[ x -eq yz ]]; then echo yes; else echo no; fi yes imadev:~$ x=3 yz=foo foo=3; if [[ x -eq yz ]]; then echo yes; else echo no; fi yes imadev:~$ x=3 yz=foo foo=2; if [[ x -eq yz ]]; then echo yes; else echo no; fi no
