October 2001
Intermediate to advanced
1040 pages
22h 50m
English
% cat datafile northwest NW Joel Craig 3.0 .98 3 4 western WE Sharon Kelly 5.3 .97 5 23 southwest SW Chris Foster 2.7 .8 2 18 southern SO May Chin 5.1 .95 4 15 southeast SE Derek Johnson 4.0 .7 4 17 eastern EA Susan Beal 4.4 .84 5 20 northeast NE TJ Nichols 5.1 .94 3 13 north NO Val Shultz 4.5 .89 5 9 central CT Sheri Watson 5.7 .94 5 13
% nawk 'NR==1{gsub(/northwest/,"southeast", $1) ;print}' datafile
southeast NW Joel Craig 3.0 .98 3 4
|
EXPLANATIONIf this is the first record (NR == 1), globally substitute the regular expression northwest with southeast, if northwest is found in the first field. |
% nawk 'NR==1{print substr($3, 1, 3)}' datafile Joe |
EXPLANATIONIf this ... |