NEWS revision 94
1Version 2.0: 2 3The most important user visible change is that egrep and fgrep have 4disappeared as separate programs into the single grep program mandated 5by POSIX 1003.2. New options -G, -E, and -F have been added, 6selecting grep, egrep, and fgrep behavior respectively. For 7compatibility with historical practice, hard links named egrep and 8fgrep are also provided. See the manual page for details. 9 10In addition, the regular expression facilities described in Posix 11draft 11.2 are now supported, except for internationalization features 12related to locale-dependent collating sequence information. 13 14There is a new option, -L, which is like -l except it lists 15files which don't contain matches. The reason this option was 16added is because '-l -v' doesn't do what you expect. 17 18Performance has been improved; the amount of improvement is platform 19dependent, but (for example) grep 2.0 typically runs at least 30% faster 20than grep 1.6 on a DECstation using the MIPS compiler. Where possible, 21grep now uses mmap() for file input; on a Sun 4 running SunOS 4.1 this 22may cut system time by as much as half, for a total reduction in running 23time by nearly 50%. On machines that don't use mmap(), the buffering 24code has been rewritten to choose more favorable alignments and buffer 25sizes for read(). 26 27Portability has been substantially cleaned up, and an automatic 28configure script is now provided. 29 30The internals have changed in ways too numerous to mention. 31People brave enough to reuse the DFA matcher in other programs 32will now have their bravery amply "rewarded", for the interface 33to that file has been completely changed. Some changes were 34necessary to track the evolution of the regex package, and since 35I was changing it anyway I decided to do a general cleanup. 36