On Sat, 22 Mar 2008 23:06:54 +0000, 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 Thank you! How do I know Ctrl-V + Ctrl-I is \t?
