search and replace with regular expressions in eclipse

eclipse supports regular expressions within his dialog ‘search and replace’ (ctrl-f). you only have to activate the corresponding checkbox ‘Regular Expressions’ in the options pane.

let’s see eclipse in action by a simple example. suppose you want to surround a couple of numbers with some text:

100 should be replaced by
INSERT INTO kredit( pk_id, fk_sicherheit ) VALUES ( 1, 100 );
200 should be replaced by
INSERT INTO kredit( pk_id, fk_sicherheit ) VALUES ( 1, 200 );
300 should be replaced by
INSERT INTO kredit( pk_id, fk_sicherheit ) VALUES ( 1, 300 );
and so on …

in most regular expression dialects you can refer to a piece of chars which are surrounded by parenthesis with the $-operator. this is also true in eclipse. with this in mind, the task is easy. now you can search for the numbers using

^([0-9]+)$

see the parenthesis around the number expression? now we can refer to the matching in the replacement:

INSERT INTO kredit( pk_id, fk_sicherheit ) VALUES ( 1, $1 );

of course you could reference some more subexpressions (also surrounded by parenthesis) by incrementing the reference counter (as you know, the order of the starting parenthesis within the expression is relevant to the reference counter – $1, $2, $3 and so on ).