
     _________________________________________________________________
                                      
                                      Omi
                                       
Table of Contents

     * What Is Omi?
     * Compilation
     * Quick Start
     * Command Line Options
     * Configuration Files and Packages
     * Debug Settings
     * Mirror Option Settings
     * Progress Display
     * Excludes and Includes
     * Timeout Settings
     * Retry and Delay Settings
     * Examples
     * Troubleshooting
       
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   _Preliminary docs for the alpha version of "omi" (Olli's Mirror)._
   
   Copyright © 1997-98 by Oliver Fromme <olli@fromme.com>
   All rights reserved worldwide. Permission is granted to use and
   distribute this software according to the BSD-style licensing terms.
   See the file BSD-COPYRIGHT for details, which is included with the
   software distribution.
   
   
    Author's address:
    Oliver Fromme, Leibnizstr. 18 / #61, 38678 Clausthal, Germany
    Email address: olli@fromme.com
    
   Notes:
   
     * This is an alpha version, and it is still in development.
     * There are bugs.
     * Several features are not implemented yet.
     * I try to make the software as portable as possible, but I usually
       test it under Solaris and FreeBSD only, so there might be a few
       difficulties when using it on different platforms.
     * The name of the software might change in the future, "omi" is just
       the current project title, because I haven't found a better one
       yet.
       
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What Is Omi?

   It is a software to _mirror_ subtrees of FTP servers. It can be used
   to make a one-time mirror, and it can be used to update a mirror
   regularly (for example using _cron_, see the manual page of
   _crontab_).
   
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Compilation

   Just type "make" for a short help text. Normally you should not have
   to edit the Makefile. Note that the compilation is done without
   optimization, but with "-g", because this is an alpha version.
   
     _________________________________________________________________
                                      
Quick Start

   If you want to mirror the directory tree /pub/foo from the FTP server
   ftp.bar.org (this host does not exist and is only used as an example)
   to your local directory /pub/mirror/foo, use the following command
   line:
   
     omi -s ftp.bar.org -r /pub/foo -l /pub/mirror/foo
     
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Command Line Options

   -h
          Display a short overview of all options.
          
   -s server
          ("Server") Specify the remote FTP server. This can be a host
          name or a numerical IP address. The -s option starts a new
          "server section", which means that all following options apply
          to this server only, until another -s option is used.
          You can also specify an optional port number here, separated
          from the host name or IP by a colon (":") or space. The default
          port number is 21.
          
   -r path
          ("RemoteDir") Specify the path of the remote directory. It must
          be an absolute path, i.e. it must start with a slash "/". The
          -r option starts a new "directory section", which means that
          all following options apply to this remote directory tree only,
          until another -r option is used. There can be multiple -r
          options per -s option.
          
   -l path
          ("LocalDir") Specify the path of the local directory, which is
          used as target for the previous -r option. There can be only
          one -l option per -r option. If there is no -l option for an -r
          option, the local path is the same as the remote path. If there
          are multiple -l options for the same -r option, only the last
          one is used. The local path can be an absolute path or relative
          to the current working directory.
          
   -d debug_options
          ("Debug" or "Verbose") Specify debug options (see section Debug
          Settings). The default is "report,stats,progress". Specify
          "help" to get a short overview of all debug options.
          
   -g group
          ("Group") Specify the group to which all files will be
          _chgrp_'ed. It can be a group name or a numerical GID.
          Specifying an empty string or -1 will disable _chgrp_ (this is
          the default).
          
   -m mode
          ("Mode") Specify the modes to be used for local files and
          directories. They must be octal. The default is "644,755" (the
          first mode is applied to plain files, the second mode is
          applied to directories). You can also specify only one number
          for both (the x-bits will be cleared for plain files, and
          copied from the r-bits for directories).
          
   -u login
          ("User" or "Login") Specify the login (user name) to use for
          the FTP server. The default is "ftp".
          
   -e email
          ("Email") Specify the email address which is used for the FTP
          login (sent as password). The default is "yourlogin@".
          _Warning:_ Do not specify a real password here, because it is
          inherently insecure!
          
   -t time
          ("Deviation") Set a maximum time deviation (in seconds) for
          file time comparison (the default is 0, i.e. no deviation). The
          meaning is this: If a file is present locally and has the same
          size as the remote file, but a different time stamp, it will
          normally be retrieved. However, if the time difference is
          smaller than the maximum deviation (set with the -t option),
          the file will not be retrieved (but the time stamp of the local
          file will be set to the time of the remote file). This is
          useful if you used a different mirror software before which had
          problems with the time stamps.
          
   -n num
          ("Newest") Only mirror the num newest files in every directory.
          num must be a non-negative number. If num is 0 (which is the
          default), all files are mirrored, no matter how old they are.
          
   -P percent
          ("RemoveLimit") Specify a _removal limit_ in percent. If the
          number of files that disappeared from the remote site in a
          certain directory is greater or equal to this value, no
          existing files will be removed from the local directory. This
          is useful if you're mirroring a server that is not reliable
          (i.e. things disappear and then reappear shortly thereafter).
          The default is 100, which means that local files will be
          removed if they disappeared from the remote site, no matter
          what. If you specify 0, _nothing_ will be removed from the
          local mirror (this is useful if you want to run an
          _accumulating_ mirror which never deletes anything, or if you
          want to delete stuff manually).
          
   -o mirror_options
          ("Options") Specify mirror options. See the section Mirror
          Option Settings for details. The default is none. Specify
          "help" to get a short overview of all mirror options.
          
   -x regex
          ("Exclude" or "RemoteExclude") Specify an exclude pattern
          (regular expression). See the section Excludes and Includes for
          details.
          
   -y regex
          ("Include" or "RemoteInclude") Specify an include pattern
          (regular expression). See the section Excludes and Includes for
          details.
          
   -X regex
          ("LocalExclude") Specify an exclude pattern for files and/or
          directories on the local machine.
          
   -Y regex
          ("LocalInclude") Specify an include pattern for files and/or
          directories on the local machine.
          
   -T timeout_options
          ("Timeout") Specify timeout values (e.g. for network accesses).
          See the section Timeout Settings for details.
          
   -R retry_options
          ("Retry") Specify retry parameters in case of errors. See the
          section Retry and Delay Settings for details.
          
   -D delay_options
          ("Delay") Specify delay parameters for "hard retries". See the
          section Retry and Delay Settings for details.
          
   -I directory
          ("IncludeDir" or "PackageDir") Specify an include directory for
          config files (or so-called "package" files). See the section on
          configuration files.
          
   -i includefile
          ("Include" or "Package") Load the specified config file (or
          so-called "package"). The -i is optional, you can omit it: Any
          file names on the command line which are not preceded by an
          option letter are interpreted as packages.
          
   -p pidfile
          ("PidFile" or "LockFile") Specify the name of a PID file, which
          is also used as a lockfile. If this file is open and locked by
          another process, an error message is printed, and the mirror
          program exits. Note that you can have a global lockfile, a
          per-server lockfile, and a per-directory lockfile. By default
          there are no lockfiles.
          
     _________________________________________________________________
                                      
Configuration Files and Packages

   You can store options in configuration files. Each command line option
   has a corresponding config file entry, and vice versa. Config files
   consist of config entries and comments. A comment is either an empty
   line, or a line which starts with a "#" character (optionally preceded
   by whitespace). The syntax of a config entry is:
   
     key value
     
   There can be an optional ":" or "=" after the key. Any whitespace
   before the key, between key and value, and after the value is ignored,
   but the value itself may contain whitespace. If you want a value to
   contain whitespace at the beginning or at the end, you have to enclose
   it in double quotes. Double quotes within the value have no special
   meaning. The value can contain the usual escape sequences: \n
   (newline), \t (tab), \\ (backslash), \NNN (octal character code), \xNN
   (hex character code), etc. You can use the shell syntax for including
   environment variables, for example $HOME or ${HOME}, or -- according
   to Makefile syntax -- $(HOME) (the latter is depreciated and will _not_
   be supported in future versions). You can also use $$ to get the PID
   (process ID) of the mirroring process. Use \$ if you need a literal
   "$" character.
   
   The following keys are recognized (note that keys are not
   case-sensitive), the corresponding command line option is given on the
   right side:
   
      Server server              -s server
      RemoteDir path             -r path
      LocalDir path              -l path
      Debug debug_options        -d debug_options
      Group group                -g group
      Mode mode                  -m mode
      Login login                -u login
      User login                 -u login
      Email email                -e email
      Deviation time             -t time
      Newest num                 -n num
      RemoveLimit percent        -P percent
      Options options            -o options
      Exclude regex              -x regex
      RemoteExclude regex        -x regex
      Include regex              -y regex
      RemoteInclude regex        -y regex
      LocalExclude regex         -X regex
      LocalInclude regex         -Y regex
      Timeout timeout            -T timeout
      Retry retry_options        -R retry_options
      Delay delay_options        -D delay_options
      IncludeDir directory       -I directory
      PackageDir directory       -I directory
      Include includefile        -i includefile
      Package includefile        -i includefile
      PidFile pidfile            -p pidfile
      LockFile pidfile           -p pidfile

   After start-up, omi first reads configuration entries from
   /usr/local/etc/omirc (if it exists), then it reads entries from
   ${HOME}/.omirc (if it exists), then it reads options and package names
   from the command line (they are used and read in the same order as
   they appear on the command line). See the examples section at the end.
   
   Note that the names of the standard config files depend on the name of
   the binary. For example, if you call the binary "foobar" instead of
   "omi", it will look for the files /usr/local/etc/foobarrc and
   ${HOME}/.foobarrc instead.
   
     _________________________________________________________________
                                      
Debug Settings

   There are a lot of possible debug settings, and describing them all
   here would probably be confusing. Therefore only the most useful and
   important ones are explained. The debug keywords are not case
   sensitive. All output is sent to the standard error output ("stderr"),
   except possibly for the progress display (see below).
   
   Report
          Report only on changes to the local mirror, and why they have
          changed. This will not produce any output at all if no updates
          have to be done.
          
   Progress
          Display the progress of file transfers in bytes and percent
          (where applicable). Note that this only works if stdout or
          stderr is associated with a terminal. See the section Progress
          Display below for details.
          
   Verbose
          Verbosely report mirroring activity and FTP server control
          input/output per file.
          
   Stats
          Print final summary statistics if mirroring activity took
          place. This will not produce any output at all if no updates
          had to be done.
          
   Statistics
          Print statistics for every remote / local directory tree pair,
          as well as final summary statistics.
          
   All
          Report on everything. _Warning:_ this can generate several
          megabytes of debug output!
          
   None
          Report on nothing, be quiet while mirroring.
          
   You can combine multiple debug keywords by separating them with
   commas, for example "Report,Stats,Progress" (which is the default).
   You can also subtract debug keywords, for example
   "All,-Statistics,-Stats" -- this will print everything, but except for
   final and per-directory statistics.
   
   If you specify debug options multiple times, the latter will replace
   (i.e. completely override) the former. So, if you want to add debug
   options to the existing ones, start the next set of options with a
   plus sign ("+"). Similarly, you can remove debug options from the
   existing set by starting them with a minus sign ("-"). Example:
   
      Debug  A,B,C,D           now in effect:  A,B,C,D
      Debug  +E,+F             now in effect:  A,B,C,D,E,F
      Debug  -B,-C             now in effect:  A,D,E,F
      Debug  A,B               now in effect:  A,B

   In the second line, "+E,F" would have had the same effect, because "+"
   is the default for the second and following keywords on a line.
   
   Note that error messages will always be printed, no matter which debug
   flags are used.
   
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Mirror Option Settings

   You can set a few mirror option flags, using "-o" on the command line,
   or using "Options" in a configuration file. The syntax is exactly the
   same as for debug options (see above). These mirror options change
   certain aspects of the default behaviour. Currently, the following
   option flags are supported:
   
   GetOlderFiles
          Normally, if a file on the local host has a newer datestamp
          than the remote file, it not be retrieved. If you set this
          flag, it will be retrieved if the timestamp is different (no
          matter whether it's older or newer).
          
   PreserveDirs
          Normally, if a local directory does not exist anymore on the
          remote server, it is removed locally (including all files and
          subdirectories in it). If you set this flag, it will be
          preserved, and a warning will be printed (unless you have set
          the debug flags to "none"). You will then have to remove that
          directory manually, or (if you want to keep it) add it to the
          local exclude list. This is useful if the remote server is
          unreliable (i.e. if parts of it disappear sometimes and then
          are back the next day).
          
   IgnoreTime
          Ignore the timestamps of remote and local files when mirroring.
          I.e. only retrieve a remote file if it doesn't already exist
          locally, or if the file sizes mismatch. Useful if some stupid
          cronjob touches all files on the remote site, even though their
          contents don't change.
          
   DontTouch
          Do not update the time stamps of local files to be the same as
          those of the remote files. This only makes sense if you also
          use the "IgnoreTime" option flag, or the "deviation" config
          entry (-t option).
          
   LocalTime
          Assume that the time stamps of the remote server are local
          time. The default (if this flag is not set) is to use GMT. Most
          UNIX-based FTP servers seem to use GMT, so this flag should not
          be used normally.
          
   ExcludeAll
          Exclude all files and directories from mirroring by default.
          Use "Include" or -y to include files and directories to be
          mirrored. See also the section Excludes and Includes.
          
   Test
          This is for testing / debugging purposes. If this flag is set,
          no modifications are performed (no transmission or deletion of
          files). Useful to test exclusion patterns etc. without the risk
          to kill any files if something doesn't work as expected.
          
   Active
          Use "active" FTP transfers (the default is to use "passive" FTP
          transfers). This can be useful if the FTP server is behind a
          firewall, of if the passive mode support of the server is
          broken. Note that omi does not automatically switch between
          active and passive transfer mode.
          
   None
          None of the above options. This is the default.
          
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Progress Display

   Omi features a progress display, which is useful to watch transferring
   long files over slow connections. It starts if the transfer of a file
   takes longer than 10 seconds, and it is updated every 5 seconds. The
   display consists of four parts:
   
     * The number of bytes transferred for this file so far.
     * How man percent of this file have been transferred.
     * The average transfer rate (bytes per second).
     * The ETA (estimated time of arrival) in hh:mm:ss.
       
   If the connection is idle for more than 10 seconds, it is declared as
   "stalled". In this case, the transfer rate and ETA are replaced by the
   duration of the idle time.
   
   Please note that the transfer rate and ETA are calculated based on the
   elapsed time so far, which means that they are not very accurate at
   the beginning, but they should become more accurate while the transfer
   is running (provided that the transfer rate doesn't change
   significantly).
   
   The progress display is enabled by default. You can disable it with
   "-d -progress" (command line) or "Debug -Progress" (configuration
   file).
   
   _Note:_ The progress display is disabled automatically if neither
   stdout nor stderr points to a regular terminal. This is the case if
   you redirect both stdout and stderr to a file or into another command
   (using a pipe). This can be a problem if you want to capture the
   regular output in a file, but you still want to watch the progress on
   the terminal. In this case, you have to redirect stdout to the
   terminal explicitly, and pipe stderr into the "tee" command (type "man
   tee" for information about tee). If you use an sh-like shell (sh, ksh,
   zsh, bash), the following command will do the trick:
   
     ( omi whatever-options-you-need > /dev/tty ) 2>&1 | tee logfile
     
   For csh-like shells (csh, zsh, tcsh), use this one:
   
     ( omi whatever-options-you-need > /dev/tty ) |& tee logfile
     
   If you do that frequently, it is probably more convenient to write a
   small shell script wrapper for the above commands. Please refer to the
   manual page of your shell to learn more about pipes and redirections.
   
   If both stdout and stderr are regular terminals (i.e. not redirected),
   the progress display will be sent to stdout. If only one of them is a
   terminal, the progress display will be sent to that one. If neither is
   a terminal, progress display is disabled. Note that normal diagnostic
   output (reports, warnings, statistics, debug output etc.) always goes
   to stderr.
   
   There are two common cases in which omi automatically does the right
   thing: (1) If you just call omi on the command line, without any
   redirections and pipes, you'll get the regular output and progress
   display as expected. (2) If you call omi via cron, there is no
   progress display. This makes sense, of course, because you cannot
   watch the progress anyway. Programs which are executed by cron don't
   have a terminal assoziated with stdout or stderr. Instead you will
   receive the output via email as soon as the job is finished (unless
   you redirect the output somewhere else, of course).
   
     _________________________________________________________________
                                      
Exludes and Includes

   Normally, omi mirrors the complete directory tree and makes an
   identical copy on the local machine. However, you often want to
   exclude certain files or directories from mirroring, or maybe you only
   want to mirror a small part of the whole directory tree.
   
   To support this, omi offers the "Exclude" and "Include" commands (-x
   and -y command line options, respectively). They take a pattern (an
   extended regular expression) as argument. A detailed description of
   extended regular expressions can be found in the following manual
   pages, depending on your operating system:
   
   Solaris: regex(5)
   FreeBSD: re_format(7)
   Digital UNIX: grep(1)
   
   _Important:_ The backslash "\" and the dollar sign "$" have a special
   meaning in omi's configuration files, so you have to escape them with
   a backslash if you want to use them in regular expressions inside a
   configuration file.
   
   There is one special thing: If the first character of the pattern is
   an exclamation mark, the whole pattern is negated. Example: the
   pattern "!stable|current" matches all files and directories that do
   _not_ contain the word "stable" or "current" somewhere. Use this
   feature whith care, since it might produce surprising results. For
   example, the exclude pattern "!\.mp3$" excludes everything which does
   not have an .mp3 extension -- however, this will _not_ mirror all
   files with an .mp3 extension, because it excludes all directories. See
   the examples section below for information about how to do this
   correctly.
   
   Every single file and directory name (the complete path) is compared
   with the list of excludes and includes (in the same order in which
   they have been specified) until a match is found. If it matches an
   exclude pattern, the respective file or directory is not mirrored,
   otherwise it is mirrored. Note that always the complete path is
   compared (for example "/pub/foo/bar/file.tar.gz"), and that
   directories have a slash appended (for example
   "/pub/foo/bar/directory/"), so you can distinguish directories from
   plain files by matching the slash at the end.
   
   If a file or directory does not match any of the patterns, it is
   mirrored by default. You can reverse this by using the "ExcludeAll"
   option flag. If you do this, be sure to include something explicitely,
   otherwise omi will not mirror anything, because everything is excluded
   by default. If you include certain files, omi automatically includes
   the directories which they're in, unless you explicitely exclude them.
   
   There is no limit on the number of exclude and include patterns.
   However, note that omi takes more CPU load and processing time if
   there are a lot of patterns and/or very complicated patterns.
   
   Here are a few examples of patterns (remember that you have to quote
   backslashes ("\\") and dollar signs ("\$") if used in config files!):
   
   exe
          Matches all files or directories that contain the string "exe"
          somewhere (in the path or in the actual name).
          
   \.exe$
          Matches all plain files with extension .exe.
          
   /pub/win
          Matches all files or directories having "/pub/win" in their
          path (this would also match
          "/pub/unix/emulators/pub/winblows").
          
   ^/pub/win$
          Matches the plain file "/pub/win".
          
   ^/pub/win/$
          Matches the directory "/pub/win".
          
   ^/pub/win/
          Matches the directory "/pub/win" and everything inside it.
          
   Note that the last two examples are equivalent if used as exclusion
   patterns: If you explicitely exclude a directory, everything in it is
   excluded, too. However, if you use them as inclusion patterns, they
   are different: The first one matches only the directory itself, the
   second one matches everything inside it (everything starting with
   "/pub/win/").
   
   Here are some "real world" examples for certain mirror tasks that
   require using exlude and/or include patterns.
   
     * We want to mirror everything, except for files called ".notar" or
       ".nocompress", or "lost+found" directories:
       
     Exclude /\\.no(tar|compress)\$
     Exclude /lost\\+found/
       
     * We want to mirror only two files, called "ls-lR.Z" and
       "Index.complete", and nothing else. In this case it would be
       difficult (or maybe even impossible) to exclude all other files,
       so we use the "ExcludeAll" option flag:
       
     Options ExcludeAll
     Include /ls-lR.Z\$
     Include /Index.complete\$
       
     * We want to mirror all files with an ".mp3" extension. Again, it's
       easiest to use the "ExcludeAll" option flag. As noted above, the
       directories that contain these files are included automatically.
       
     Options ExcludeAll
     Include \\.mp3\$
       
     * We want to exclude all files which contain the word "hate", except
       for those which also contain the word "love". Note that the order
       matters in this case, because the first pattern that matches takes
       effect.
       
     Include love
     Exclude hate
       
     * This is a similar example: We want to exclude everything
       containing the word "linux" or "Linux", except for the files in a
       directory "FreeBSD". So "FreeBSD/emu/linux" would be mirrored, but
       "somewhere/else/linux" would not. Again, the order matters in this
       case.
       
     Include /FreeBSD/
     Exclude [Ll]inux
       
     * We want to mirror all files with an ".jpg" or an ".png" extension,
       except for those containing the word "sex" or "xxx". The order
       matters in this case, too.
       
     Options ExcludeAll
     Exclude sex|xxx
     Include \\.jpg\$
     Include \\.png\$
       
     _________________________________________________________________
                                      
Timeout Settings

   The mirror software uses several timeout values when accessing the
   network. If a timeout expires, the connection is closed and re-opened,
   and the operation which has been interrupted is repeated (unless a
   certain maximum number of retries has been reached; in this case the
   current mirror process is aborted with a fatal error). The intention
   of this timeout mechanism is to avoid situations in which the network
   connection hangs for a long time. Currently, the following timeout
   values are supported:
   
     * DNS timeout ("D"), default 2 minutes: The maximum time allowed for
       a name server look-up.
     * Connect timeout ("N"), default 2 minutes: The maximum time allowed
       for an FTP connection to be established. This applies to the
       control connection as well as to the data connection.
     * Command timeout ("M"), default 3 minutes: The maximum time for an
       FTP command to be sent to the FTP server.
     * Read timeout ("R"), default 10 minutes: This is the timeout for
       reading data from the FTP server. If the software does not receive
       at least one byte within this time, this timeout expires.
       
   You can change the timeout values, using "-T" on the command line, or
   using "Timeout" in a configuration file. First you have to specify the
   letter for the type of the timeout ("D" = DNS, "N" = connect, "M" =
   command, "R" = read), followed by the number of seconds for this
   timeout. You can also specify it in minutes or hours if you append an
   "M" or "H", respectively. You can specify multiple timeouts,
   separating them by commas. Example:
   
     Timeout D60, R5m
     
   This sets the DNS timeout to 60 seconds and the read timeout to 5
   minutes. The letters are not case-sensitive.
   
   Note that if you set a timeout value to zero, that timeout is
   disabled, i.e. the respective operation may hang forever.
   
     _________________________________________________________________
                                      
Retry and Delay Settings

   If an error occurs while accessing the remote server, the software
   tries to repeat the command which caused the error (this is called a
   "soft retry"). If a certain number of soft retries occured in a row,
   the software closes the connection to the server, waits for some time,
   then re-opens the connection and tries to repeat the failed command
   again (this is called a "hard retry"). A hard retry is also performed
   if a soft retry wouldn't help (for example, if the connection to the
   server was lost or timed out). If a certain number of hard retries
   occured for the same server, the software "gives up".
   
   You can change the retry parameters, using "-R" on the command line,
   or using "Retry" in a configuration file, followed by one or more
   specifications (separated by commas) which consist of a letter
   followed by a number. The letter indicates which parameter is to be
   changed:
   
     * Soft retries ("S"), default 10: At most this many soft retries
       will be performed in a row, before a hard retry is enforced. (The
       internal counter for soft retries is reset to zero when the
       command is successul or when a hard retry is done.)
       Note: Do not set this number too high, otherwise the software
       might waste lots of time and bandwidth with soft retries in cases
       when a hard retry is necessary.
     * Hard retries ("H"), default 10: At most this many hard retries
       will be performed before the software gives up trying the
       respective command (unrecoverable failure). (The internal counter
       for hard retries is reset to zero when the command is successul or
       when an unrecoverable failure occurs.)
     * Unrecoverable failures ("F"), default 10: If this many failures
       occured for a server, the software assumes that this server is
       broken, or the connection to it is too bad right now. In this
       case, mirroring from this server is stopped completely.
     * Local errors ("L"), default 10: This one is different from the
       above ones, as it affects local errors. If a local error occurs,
       it's usually one of these:
          + disk quota exceeded
          + no space left on device
          + permission denied
       All of these are normally unrecoverable and affect the complete
       mirror (not only one file). Therefore the software stops mirroring
       from the current server if the number of local errors reaches this
       value.
       
   The following example sets the default retry parameters (the letters
   are not case-sensitive, and whitespace is optional):
   
     Retry s 10, h 10, f 10, l 10
     
   Note that with the default values there will be at most 110 retries
   for a single operation (for example to retrieve a file): First 10 soft
   retries, then a hard retry, then another 10 soft retries, etc., until
   10 hard retries have been done (each of them preceded by 10 soft
   retries).
   
   If a hard retry occurs, the software waits some time (the default is
   25 seconds) before the connection is re-opened. If multiple hard
   retries occur in a row, this delay is increased until a maximum value
   is reached. You can change the delay settings, using "-D" on the
   command line, or using "Delay" in a configuration file, followed by
   one or more specifications (separated by commas) which consist of a
   letter followed by a time value (similar to the timeout
   specifications, see above). The letter indicates which delay setting
   is to be changed:
   
     * Initial delay ("D"), default 25 seconds. This is the delay for the
       first hard retry that occurs for a certain command.
     * Delay increment ("I"), default 25 seconds. Every time another hard
       retry for the same command occurs, the delay increases by this
       value.
     * Maximum delay ("M"), default 15 minutes. The delay will not
       increase beyond this value.
       
   The following example specifies the default delay settingss (the
   letters are not case-sensitive, and whitespace is optional):
   
     Delay d 25s, i 25s, m 15m
     
   With these settings, the first delay in a row of hard retries will be
   25 seconds, the seconds one will be 50 seconds, the third one 75
   seconds, etc., until the maximum of 15 minutes is reached.
   
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Examples

   This is a sample ${HOME}/.omirc configuration file:
   
      #
      #   This is my ~/.omirc
      #

      Debug      report,statistics
      Group      ftpadm
      Mode       644,2755
      PackageDir $HOME/mirror

   Then you can put "package files" for different mirrors into your
   directory ${HOME}/mirror. This is a sample package file, which could
   be called ${HOME}/mirror/freebsd:
   
      #
      #   This is my ~/mirror/freebsd
      #

      Server     ftp7.de.freebsd.org
      Group      bsd
      Mode       664,2775

      RemoteDir  /pub/FreeBSD/ports-current
      LocalDir   /pub/mirror/FreeBSD/ports-current
      Exclude    /astro/|/biology/

      RemoteDir  /pub/FreeBSD/newsletter
      LocalDir   /pub/mirror/FreeBSD/newsletter

      RemoteDir  /pub/FreeBSD/docs
      LocalDir   /pub/mirror/FreeBSD/docs

   Note that in this example, the group and permission modes are
   overridden for this package. If the "Group" entry would have been
   specified after the first "RemoteDir" entry, it would apply only to
   that directory tree, but not to the two other ones. Likewise, the
   "Exclude" line only applies to the first directory tree (the one which
   mirrors "ports-current").
   
   In this sample scenario, you can just type "omi freebsd" to start the
   mirror (or put it in your crontab if you want to run the mirror
   regularly).
   
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Troubleshooting

   _First of all_, be sure you have read and understood the omi
   documentation. If you haven't done that, you certainly will run into
   trouble.
   
   When some problem occurs, check whether it is reproducible. If it is
   not, then probably the FTP server had a temporary failure (a shut-down
   or something similar). If the problem persists, read on.
   
   Basically, all problems fall into one of these classes:
   
     1. User errors
     2. Incompatibilities between omi and the FTP server
     3. FTP server errors (network problems or ftpd bugs)
     4. Omi errors (bugs)
     
   Class 1 has already been discussed in the first paragraph.
   
   Class 2 is difficult. Unfortunately, RFC 959 (the standard which
   specifies the FTP protocol) is not very clear in some parts. For
   example, it does not specify a reliable way to retrieve
   machine-readable directory listings. Therefore, omi has to rely on
   certain assumptions. One of them is the directory format, which is
   assumed to be more or less UNIX- style "ls -l" output. If this is not
   the case, there isn't much that can be done about it. Bad luck.
   
   Class 3 might be easier (or maybe not). If the connection to the
   server is very bad, try increasing the timeout values and the retry
   counts. If the connection is not that bad, but you still get timeouts
   right from the start, this might be caused by the fact that the FTP
   server is behind a fire- wall which doesn't allow arbitrary FTP data
   connections. In this case, try using the option for "active" FTP
   transfer mode. However, if you're behind a firewall yourself, active
   FTP transfers will probably not work.
   
   Class 4: Bugs in omi. If you find one of these, please submit a bug
   report to the author, and try to include as much information as
   possible. If I can't reproduce the problem, I can't fix it.
   
   Here are a few hints which are helpful when trying to solve problems.
   
   The most important thing is to use omi's debug settings, in order to
   increase the amount of debugging output (see the section Debug
   Settings). If you suspect a problem with the FTP protocol between omi
   and the FTP server, use this setting:
   
     -d +connect,output,input
     
   This will display the status of the connection to the FTP server, all
   commands that are sent to it, and and all replies that are received
   from it. Some knowledge of the FTP standard (RFC 959) is necessary to
   interpret the result. Note that the server sometimes sends multi-line
   messages, of which only the last line is displayed (which is usually
   the important one). If you want to see the complete messages, add the
   debug setting "multi" to those given above.
   
   If you have trouble with regular expressions (exclude or include
   patterns), the following setting might shed some light on it:
   
     -d +regex
     
   For every local and remote file, it will be displayed if it matched
   any pattern. Also, the exact file name used for matching is displayed.
   If you're only interested in remote files, use "+remote-regex" instead
   (likewise "+local-regex" for local files only).
   
   If you suspect that omi does not parse the directory listing of the
   FTP server correctly, the following might help:
   
     -d +parse
     
   It displays the parse tree, i.e. the internal representation of the
   directory structure after omi has parsed the listing of the FTP
   server.
   
   Finally, the following setting will give you everything that omi could
   possibly say:
   
     -d all
     
   Note that this produces _huge_ amounts of debug output, most of which
   is probably not useful for you.
   
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