Hi!
According to the documentation, mawk is preferred over gawk because it
is faster. Here's an interesting phenomenon:
| ~/src/fileutils % time AWK=mawk ~ace/autoconf -m ~ace
| 16,40s user 0,26s system 95% cpu 17,512 total
| ~/src/fileutils % time AWK=gawk ~ace/autoconf -m ~ace
| 7,68s user 0,27s system 98% cpu 8,067 total
What's so expensive is the finalizing loop which uses a small AWK
script. If you concentrate the measure on this very script, the
performance penalty is frightening:
| ~/src/fileutils % cat > /tmp/finalize.awk
| {
| sub(/[ ]*$/, "")
| if ($0 == "")
| {
| if (!duplicate)
| print
| duplicate = 1
| next
| }
| duplicate = 0
| oline++
| while (sub(/__oline__/, oline))
| continue
| while (sub(/@<:@/, "["))
| continue
| while (sub(/@:>@/, "]"))
| continue
| while (sub(/@S\|@/, "$"))
| continue
| while (sub(/@%:@/, "#"))
| continue
| print
| }
| ~/src/fileutils % time mawk -f /tmp/finalize.awk < configure >/dev/null
| 9,51s user 0,02s system 100% cpu 9,521 total
| ~/src/fileutils % time gawk -f /tmp/finalize.awk < configure >/dev/null
| 0,89s user 0,01s system 101% cpu 0,890 total
So, should we change AC_PROG_AWK? Should the package Autoconf use a
different macro?
Akim
