| |||||||||||||
Evolution of shells in Linux (developerWorks)Evolution of shells in Linux (developerWorks)Posted Dec 9, 2011 20:09 UTC (Fri) by nybble41 (subscriber, #55106)In reply to: Evolution of shells in Linux (developerWorks) by HelloWorld Parent article: Evolution of shells in Linux (developerWorks)
Technically it *will* work, but only because the value of the variable is output in the first iteration of the loop, and the following iterations have no effect (${var[1..N]} are empty). I.e., aside from the obvious inefficiency, the entire loop is equivalent to:
echo -n "$var"
To work as intended the variable reference would need to use substring syntax, "${var:$x:1}", rather than the array syntax "${var[$x]}". However, it is sufficient to place the variable in double-quotes, which (in bash) causes the value to be output verbatim, with no further quoting, expansion, or splitting.
(Log in to post comments)
Evolution of shells in Linux (developerWorks) Posted Dec 9, 2011 20:13 UTC (Fri) by HelloWorld (guest, #56129) [Link]
> Technically it *will* work, but only because the value of the variable is output in the first iteration of the loop,
No, the loop starts at 1 instead of 0.
Evolution of shells in Linux (developerWorks) Posted Dec 9, 2011 20:25 UTC (Fri) by nybble41 (subscriber, #55106) [Link]
Hm. You're right, which is strange since both arrays and characters are zero-indexed (except for $@). Perhaps that loop was written for a different shell entirely? It's certainly not necessary in reasonably modern implementations (i.e. within the last decade) of bash.
Evolution of shells in Linux (developerWorks) Posted Dec 10, 2011 3:34 UTC (Sat) by mathstuf (subscriber, #69389) [Link]
Nope, I was a typo. Somehow I missed that it just printed something on the first iteration, and nothing on the rest... Not sure how I forgot about printf either.
|
|||||||||||||