Minor typo.

[finddup.git] / finddup.1

diff --git a/finddup.1 b/finddup.1
index 71e0e57..896cc88 100644 (file)
--- a/finddup.1
+++ b/finddup.1
@@ -1,4 +1,4 @@
-.TH "FINDDUP" 1 "Mar 2010" "Francois Fleuret" "User Commands"
+.TH "FINDDUP" "1.2" "Apr 2011" "Francois Fleuret" "User Commands"

 
 \" This man page was written by Francois Fleuret <francois@fleuret.org>
 \" and is distributed under a Creative Commons Attribution-Share Alike
 
 \" This man page was written by Francois Fleuret <francois@fleuret.org>
 \" and is distributed under a Creative Commons Attribution-Share Alike


@@ -10,86 +10,136 @@ finddup \- Find files common to two directories (or not)
 
 .SH "SYNOPSIS"
 
 
 .SH "SYNOPSIS"
 

-\fBfinddup\fP [OPTION]... DIR1 [[not:]DIR2]
+\fBfinddup\fP [OPTION]... [DIR-OR-FILE1 [[and:|not:]DIR-OR-FILE2]]

 
 .SH "DESCRIPTION"
 
 
 .SH "DESCRIPTION"
 

-With a single directory argument, \fBfinddup\fP prints the duplicated
-files found in it. With two directories, it prints either the files
-common to both DIR1 and DIR2, or with the `not:' prefix, the ones
-present in DIR1 and not in DIR2.
+With one directory as argument, \fBfinddup\fP prints the duplicated
+files found in it. If no directory is provided, it uses the current
+one as default.

 
 

-It compares files by first comparing their sizes, hence goes
+With two directories, it prints either the files common to both DIR1
+and DIR2 or, with the `not:' prefix, the ones present in DIR1 and not
+in DIR2. The `and:' prefix is assumed by default and necessary only if
+you have a directory name starting with `not:'. Files are handled like
+directories containing a single file.
+
+This command compares files by first comparing their sizes, hence goes

 reasonably fast.
 
 reasonably fast.
 

-When looking for identical files, \fBfinddup\fP associates by default
-a group ID to every content, and prints it along the file names.
+When looking for identical files, \fBfinddup\fP associates a group ID
+to every content, and prints it along the file names. Use the \fB-g\fP
+to switch it off.

 
 Note that
 .B finddup DIR
 
 Note that
 .B finddup DIR

-is the same as
+is virtually the same as

 .B finddup -i DIR DIR
 
 .SH "OPTIONS"
 .TP
 .B finddup -i DIR DIR
 
 .SH "OPTIONS"
 .TP

-\fB-h\fR
-display help and exit
+\fB-v\fR, \fB--version\fR
+print the version number and exit
+.TP
+\fB-h\fR, \fB--help\fR
+print the help and exit

 .TP
 .TP

-\fB-d\fR
+\fB-d\fR, \fB--ignore-dots\fR

 ignore files and directories starting with a dot
 .TP
 ignore files and directories starting with a dot
 .TP

-\fB-c\fR
-do not show which files from DIR2 corresponds to files from DIR1
+\fB-0\fR, \fB--ignore-empty\fR
+ignore empty files
+.TP
+\fB-c\fR, \fB--hide-matchings\fR
+do not show which files from DIR2 correspond to files from DIR1

 (hence, show only the files from DIR1 which have an identical twin in
 DIR2)
 .TP
 (hence, show only the files from DIR1 which have an identical twin in
 DIR2)
 .TP

-\fB-g\fR
+\fB-g\fR, \fB--no-group-ids\fR

 do not show the file group IDs
 .TP
 do not show the file group IDs
 .TP

-\fB-p\fR
+\fB-t\fR, \fB--time-sort\fR
+sort files in each group according to the modification times
+.TP
+\fB-q\fR, \fB--trim-first\fR
+do not print the first file in each group
+.TP
+\fB-p\fR, \fB--show-progress\fR

 show progress information in stderr
 .TP
 show progress information in stderr
 .TP

-\fB-r\fR
+\fB-r\fR, \fB--real-paths\fR

 show the real path of the files
 .TP
 show the real path of the files
 .TP

-\fB-i\fR
+\fB-i\fR, \fB--same-inodes-are-different\fR

 files with same inode are considered as different
 files with same inode are considered as different

+.TP
+\fB-e \fI<command>\fR, \fB--exec \fI<command>\fR
+execute the provided command for each group of identical files, with
+their names as arguments
+.TP
+\fB-f \fI<string>\fR, \fB--result-prefix \fI<string>\fR
+for each group of identical files, write one result file whose name is
+the given prefix string followed by the group number, and containing
+one file name per line

 
 .SH "BUGS"
 
 None known, probably many. Valgrind does not complain though.
 
 
 .SH "BUGS"
 
 None known, probably many. Valgrind does not complain though.
 

+Since files with same inodes are considered as different when looking
+for duplicates in a single directory, there are weird behaviors -- not
+bugs -- with hard links.
+
+The current algorithm is dumb, as it does not use any hashing of the
+file content.
+
+Here are the things I tried, which did not help at all: (1) Computing
+md5s on the whole files, which is not satisfactory because files are
+often not read entirely, hence the md5s cannot be properly computed,
+(2) computing XORs of the first 4, 16 and 256 bytes with rejection as
+soon as one does not match, (3) reading files in parts of increasing
+sizes so that rejection could be done with only a small fraction read
+when possible, (4) using mmap instead of open/read.
+

 .SH "WISH LIST"
 
 The format of the output should definitely be improved. Not clear how.
 
 .SH "WISH LIST"
 
 The format of the output should definitely be improved. Not clear how.
 

-The comparison algorithm could definitely use some MD5 kind of
-signature. However, I doubt it would improve speed much.
-
-Their should be some fancy option to link two instances of the command
-running on different machines to reduce network disk accesses.
+There could be some fancy option to link two instances of the command
+running on different machines to reduce network disk accesses. This
+may not help much though.

 
 .SH "EXAMPLES"
 
 
 .SH "EXAMPLES"
 

-.B finddup -cg blah something
+.B finddup -p0d blah
+
+.fi
+List duplicated files in directory ./blah/, show a progress bar,
+ignore empty files, and ignore files and directories starting with a
+dot.
+
+.B finddup -qtg

 
 .fi
 
 .fi

-List files found in \fB./blah/\fR which have a matching file with same
-content in \fB./something/\fR. Do not display the group IDs.
+List all files which are duplicated in the current directory, do not
+show the oldest in each each group of identical ones, and do not show
+group numbers. This is what you could use to list what files to
+remove.

 
 .P
 .B finddup sources not:/mnt/backup
 
 .fi
 List all files found in \fB./sources/\fR which do not have
 
 .P
 .B finddup sources not:/mnt/backup
 
 .fi
 List all files found in \fB./sources/\fR which do not have

-content-matching equivalent in \fB/mnt/backup\fR.
+content-matching equivalent in \fB/mnt/backup/\fR.

 
 .P
 
 .P

-.B finddup tralala cuicui
+.B finddup -g tralala cuicui

 
 .fi
 List groups of files with same content which exist both in
 
 .fi
 List groups of files with same content which exist both in

-\fB./tralala/\fR and \fB./cuicui/\fR.
+\fB./tralala/\fR and \fB./cuicui/\fR. Do not show group IDs, instead
+write empty lines between groups of files of same content.

 
 .SH "AUTHOR"
 
 
 .SH "AUTHOR"