On 4 April 2011 03:53, erik quanstrom <[email protected]> wrote:
> i think this is what you want
>
> for(line in `{ifs=$nl cat}){...}
no, because that only sets ifs for the cat command, not
for the `{} construct.
ifs=$nl for (line in `{cat}) { ... }
is perhaps what you meant to say.
> but i have no idea why one would avoid the read
> idiom. for large input, forking off a read for each
> line keeps the memory footprint O(1).
FWIW, i think that avoiding a read(1) loop is
perfectly reasonable thing to want to do.
a quick test i measured that calling read in
shell loop was about 100 times slower than
using `{}, and about 500 times slower than
using awk to read the lines.
in general, unless it was truly necessary, i would
try to use awk or sed rather than use read(1) in
a loop when i was going to deal with significantly
sized input.
when i've needed a "-n safe" version of echo in
the past, i've used something like this:
fn myecho {echo -n $"* ^ '
'}
