Removed the MD5 option which was useless.

[finddup.git] / finddup.1

diff --git a/finddup.1 b/finddup.1
index 46a4326..e262386 100644 (file)
--- a/finddup.1
+++ b/finddup.1
@@ -61,27 +61,17 @@ show the real path of the files
 .TP
 \fB-i\fR, \fB--same-inodes-are-different\fR
 files with same inode are considered as different
-.TP
-\fB-m\fR, \fB--md5\fR
-use MD5 hashing
 
 .SH "BUGS"
 
 None known, probably many. Valgrind does not complain though.
 
-The MD5 hashing is not satisfactory. It is computed for a file only if
-the said file has to be read fully for a comparison (i.e. two files
-match and we have to read them completely).
-
-Hence, in practice lot of partial MD5s are computed, which costs a lot
-of cpu and is useless. This often hurts more than it helps, hence it
-is off by default. The only case when it should really be useful is
-when you have plenty of different files of same size, and lot of
-similar ones, which does not happen often.
-
-Forcing the files to be read fully so that the MD5s are properly
-computed is not okay neither, since it would fully read certain files,
-even if we will never need their MD5s.
+The current algorithm is dumb, that is it does not use any hashing of
+the file content. I tried md5 on the whole file, which is not
+satisfactory because files are often never read entirely hence the md5
+can not be properly computed. I also tried XOR of the first 4, 16 and
+256 bytes with rejection as soon as one does not match. Did not help
+either.
 
 .SH "WISH LIST"