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diff --git a/winsup/cygwin/regexp/README b/winsup/cygwin/regexp/README deleted file mode 100644 index 37d6f51c7..000000000 --- a/winsup/cygwin/regexp/README +++ /dev/null @@ -1,84 +0,0 @@ -This is a nearly-public-domain reimplementation of the V8 regexp(3) package. -It gives C programs the ability to use egrep-style regular expressions, and -does it in a much cleaner fashion than the analogous routines in SysV. - - Copyright (c) 1986 by University of Toronto. - Written by Henry Spencer. Not derived from licensed software. - - Permission is granted to anyone to use this software for any - purpose on any computer system, and to redistribute it freely, - subject to the following restrictions: - - 1. The author is not responsible for the consequences of use of - this software, no matter how awful, even if they arise - from defects in it. - - 2. The origin of this software must not be misrepresented, either - by explicit claim or by omission. - - 3. Altered versions must be plainly marked as such, and must not - be misrepresented as being the original software. - -Barring a couple of small items in the BUGS list, this implementation is -believed 100% compatible with V8. It should even be binary-compatible, -sort of, since the only fields in a "struct regexp" that other people have -any business touching are declared in exactly the same way at the same -location in the struct (the beginning). - -This implementation is *NOT* AT&T/Bell code, and is not derived from licensed -software. Even though U of T is a V8 licensee. This software is based on -a V8 manual page sent to me by Dennis Ritchie (the manual page enclosed -here is a complete rewrite and hence is not covered by AT&T copyright). -The software was nearly complete at the time of arrival of our V8 tape. -I haven't even looked at V8 yet, although a friend elsewhere at U of T has -been kind enough to run a few test programs using the V8 regexp(3) to resolve -a few fine points. I admit to some familiarity with regular-expression -implementations of the past, but the only one that this code traces any -ancestry to is the one published in Kernighan & Plauger (from which this -one draws ideas but not code). - -Simplistically: put this stuff into a source directory, copy regexp.h into -/usr/include, inspect Makefile for compilation options that need changing -to suit your local environment, and then do "make r". This compiles the -regexp(3) functions, compiles a test program, and runs a large set of -regression tests. If there are no complaints, then put regexp.o, regsub.o, -and regerror.o into your C library, and regexp.3 into your manual-pages -directory. - -Note that if you don't put regexp.h into /usr/include *before* compiling, -you'll have to add "-I." to CFLAGS before compiling. - -The files are: - -Makefile instructions to make everything -regexp.3 manual page -regexp.h header file, for /usr/include -regexp.c source for regcomp() and regexec() -regsub.c source for regsub() -regerror.c source for default regerror() -regmagic.h internal header file -try.c source for test program -timer.c source for timing program -tests test list for try and timer - -This implementation uses nondeterministic automata rather than the -deterministic ones found in some other implementations, which makes it -simpler, smaller, and faster at compiling regular expressions, but slower -at executing them. In theory, anyway. This implementation does employ -some special-case optimizations to make the simpler cases (which do make -up the bulk of regular expressions actually used) run quickly. In general, -if you want blazing speed you're in the wrong place. Replacing the insides -of egrep with this stuff is probably a mistake; if you want your own egrep -you're going to have to do a lot more work. But if you want to use regular -expressions a little bit in something else, you're in luck. Note that many -existing text editors use nondeterministic regular-expression implementations, -so you're in good company. - -This stuff should be pretty portable, given appropriate option settings. -If your chars have less than 8 bits, you're going to have to change the -internal representation of the automaton, although knowledge of the details -of this is fairly localized. There are no "reserved" char values except for -NUL, and no special significance is attached to the top bit of chars. -The string(3) functions are used a fair bit, on the grounds that they are -probably faster than coding the operations in line. Some attempts at code -tuning have been made, but this is invariably a bit machine-specific. |