bug#47001: Feature request: give a meaning to -A/-B/-C with -o

[Gregory Heytings]

Hi list,

Grep gives no meaning to the -A/-B/-C flags when they are used together 
with the -o flag (and prints a warning when they are used together).

I suggest to give them a specific meaning when the -o flag is used, namely 
to print NUM _characters_ of trailing/leading/output context around the 
match.

Currently this behavior can be obtained with "grep -oE 
'.{0,A}expose_frame.{0,B}'", where A and B are the number of leading and 
trailing context characters, but it is not efficient, and can become very 
inefficient for "large" values of A and B (say, 40).

Thanks,

Gregory