Firefox history.dat partially deleted

Have a look at http//philwilson.org/blog/2005/01/how-to-export-firefoxs-history-to-text.html this has other links as well to some Perl scripts to parse the history.dat file.

Incidentally, an interesting selection of information from within the Perl Script
# In Netscape Navigator 1.0 through 4.0, the history.db file was just a
# Berkeley DBM file. You could trivially bind to it from Perl, and
# pull out the URLs and last-access time. In Mozilla, this has been
# replaced with a "Mork" database for which no tools exist.
#
# Let me make it clear that McCusker is a complete barking lunatic.
# This is just about the stupidest file format I've ever seen.
#
# http//www.mozilla.org/mailnews/arch/mork/primer.txt
# http//jwz.livejournal.com/312657.html
# http//www.jwz.org/doc/mailsum.html
# http//bugzilla.mozilla.org/show_bug.cgi?id=241438
#
# In brief, let's count its sins
#
# - Two different numerical namespaces that overlap.
#
# - It can't decide what kind of character-quoting syntax to use
# Backslash? Hex encoding with dollar-sign?
#
# - C++ line comments are allowed sometimes, but sometimes // is just
# a pair of characters in a URL.
#
# - It goes to all this serious compression effort (two different
# string-interning hash tables) and then writes out Unicode strings
# without using UTF-8 writes out the unpacked wchar_t characters!
#
# - Worse, it hex-encodes each wchar_t with a 3-byte encoding,
# meaning the file size will be 3x or 6x (depending on whether
# whchar_t is 2 bytes or 4 bytes.)
#
# - It masquerades as a "textual" file format when in fact it's just
# another binary-blob file, except that it represents all its magic
# numbers in ASCII. It's not human-readable, it's not hand-editable,
# so the only benefit there is to the fact that it uses short lines
# and doesn't use binary characters is that it makes the file bigger.
# Oh wait, my mistake, that isn't actually a benefit at all.
#
# Pure comedy.
#
# Copyright © 2004 Jamie Zawinski

-)