On Sunday 23 March 2008 12:37:29 Sjoerd Mullender wrote: > On 2008-03-23 00:06, Nicholas Robinson wrote: > > On Saturday 22 March 2008 21:38:46 Nicholas Robinson wrote: > >> On Saturday 22 March 2008 21:18:11 Amadeus W.M. wrote: > >>> You would think specifying tab as a field separator for sort would work > >>> like this: > >>> > >>> cat file | sort -k 3 -t "\t" > >>> > >>> It doesn't: > >>> > >>> sort: multi-character tab `\\t' > >>> > >>> > >>> So after a little search and some trial and error I got this to work: > >>> > >>> cat file | sort -k 3 -t "`/bin/echo -e '\t'`" > >>> > >>> > >>> For my own curiosity, can someone please illuminate me as to why the > >>> first incantation does not work as expected? Is there a more natural > >>> way to specify \t other than echo? > >> > >> Take the double quotes out in your first attempt. So command becomes > >> > >> cat file | sort -k 3 -t \t > >> > >> Nick > > > > Sorry, I was a little bit quick off the mark. The \t doesn't yield a tab > > character (see below) as you were implying and I went along with in the > > first example! If you take the double quotes out as I suggested, then the > > field separator becomes the character t! > > > > I think (being a little more cautious this time!) that you want: > > > > \ followed by Ctrl V followed by Ctrl I > > > > If I remember correctly, sort interprets a tab as a default field > > separator anyway. > > > > As to the why: it is because the -t takes an argument which is a > > character. Putting double quotes around it stops the \ being elided and > > so \t as two characters \ and t are presented to sort which is expecting > > only one character. Hence its moan. Try echo "\t" and you will see what I > > mean. > > > > In my second attempt above, the Ctrl V stops the tab character (Ctrl I) > > being expanded on the command line and the \ joins the tab character to > > the t. > > > > HTH > > > > Nick > > Easier: > sort -k 3 -t $'\t' > > See `man bash' and look for $'string'. > Easier? More characters certainly!
