Lazy regex with OR

I have strings of the form:

greengrocerabc
sandwichcba
oscardcba

I'd like to lazily match开发者_C百科 abc, abcd and abcde, so I can get the first component. So something like

sub("^(.+)(abc|cba|dcba)", "\\1", "oscardcba") => "oscar"

However, regexp OR greedy matches cba and I get oscard

How can I lazy match this OR? The language is R, but it can can act like grep or perl.

Then make the quantifier non-greedy:

^(.+?)(abc|cba|dcba)

This way, the capture group will only contain the shortest possible match (which will not include abc, cba or dcba).

Further reading:

• http://www.regular-expressions.info/