Mail Archives: djgpp/2001/07/25/06:16:46
On Tue, 24 Jul 2001, Juan Manuel Guerrero wrote:
> 1) I have compiled using the GNU regex implementation included
> in the sed sources and not the DJGPP libc regex. GNU regex is
> superior to the DJGPP regex. If you inspect the sed302b.zip
> package you will find a second sed binary called gsed.exe.
> That one is the out-of-the-box compiled sed binary. That sed
> program has been compiled with GNU regex and that binary must
> be compared with the sed binary from sed3028b.zip.
> The sed.exe from sed302b.zip has been created by Eli using
> the regex functions from DJGPP 2.03.
I'd advise to keep the two executables in the distribution, and to
make the binary built with libc's regex the default, named sed.exe.
That's because the version of GNU regex which comes with Sed produces
an executable that is 2-4 times slower on common jobs. I'm told that
this is due to some bug or misfeature in GNU regex, but until it is
fixed, I don't think we should punish users. Sed is used heavily in
configure scripts, and it doesn't make sense to slow them down by such
a large factor.
I put gsed.exe into the distribution because the libc's regex takes
about forever on some _extremely_ complicated regular expressions,
where GNU regex takes a long, but finite time. For example, the
venerable dc.sed script, which implements an RPN calculator with Sed
commands (!) takes so long with our regex that I was never able to
wait long enough for it to finish.
Experience shows that the problems in libc's regex routines never
surface for the absolute majority of DJGPP users: I've never seen any
question here that would require to tell the questor to use gsed.exe.
So if someone considers how to make only one executable, I'd recommend
to build it with libc's regex, not with GNU regex.
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