--
I'm not belgian but I play one on TV.

Incorrect. The only chance for zgrep to succeed is that your data is too small, so zip used "store" instead of the "deflate" algorithm. To wit:

% perl -e 'print "DB_File" x 1000' > test.txt
% zip test.zip test.txt
% zgrep DB_File test.zip |wc
       0       0       0

[user@dirty-bastard ddate]$ zipinfo ddate.zip

Archive:  ddate.zip   20000 bytes   7 files
-rw----     2.0 fat    5145 tx defX 13-Feb-99 05:00 DDATE.MAN
-rw----     2.0 fat    4917 tx defX 13-Feb-99 05:00 DDATE.TXT
-rw----     2.0 fat   10529 tx defX 13-Feb-99 05:00 DDATE2D3.C
-rwx---     2.0 fat    9658 bx defX 13-Feb-99 05:00 DDATE2D3.EXE
-rw----     2.0 fat   10427 tx defX 13-Feb-99 05:00 DDATE3D3.C
-rw----     2.0 fat     431 tx defX 13-Feb-99 05:00 MANIFEST
-rw----     2.0 fat     772 tx defX 13-Feb-99 05:00 WHATS.NEW
7 files, 41879 bytes uncompressed, 19116 bytes compressed:  54.4%
[download]

[user@dirty-bastard ddate]$ zgrep ddate ddate.zip

       ddate - converts Gregorian dates to Discordian dates
         therefore getting ready to complain that  ddate  returns
       C:\> ddate
       C:\> ddate +"Today is %{%A, the %e of %B%}, %Y. %N%nCelebrate %
+H"
       C:\> ddate +"It's %{%A, the %e of %B%}, %Y. %N%nCelebrate %H" 9
+ 26 1995
       C:\> ddate +"Today's %{%A, the %e of %B%}, %Y. %N%nCelebrate %H
+" 2 29 1996
       ddate   returns  non-NULL   values  for   September 3 rd -
       today etc. ddate won't stop stop you from telling it there
[download]

--
I'm not belgian but I play one on TV.