SPACE 2/SPACE - Library 2 - Volume 1.iso/utility/557/dbackup/dbackup.man

Text File | 1991-10-19 | 10.5 KB | 199 lines

NAME
    dbackup - a backup program for people with removable hard disks

SYNOPSIS
    dbackup [options] [source] [destination]
    dbackup [-fhktv]  [-[o|x] <suffixes>]             [source] <destination>
    dbackup [-l <format>] [-fhv] [-[o|x] <suffixes>]  [source]
    dbackup [-a <utility> <line>] [-r <size>] [-fhkv] [source] <destination>
    dbackup [-[c|s|m]fhv] [-[o|x] <suffixes>]         [source]

DESCRIPTION
    dbackup is a program primarily targetted at people who have relatively
    large removable medias. Normally, a backup program is often dedicated for
    a specific removable media which, in face of evolution, at some time from
    the point of design and creation cannot support a new media. What I'm
    particulary refering to is, of course, backup programs relying totally on
    floppy disks. Since this was one of the objectives with this project, I
    have tried to eliminate any such dependencies and it should work on any
    media that I know of. It has been tried with mixes of hard disks,
    floppies, and a 10 Mbyte removable floppy disk unit (a Supra FD-10 based
    on a Konica mechanism). In respect with this specification, this program
    now have many similarites to simple copy statements found in most shells
    and command line interpreters, indeed it does work best if called from
    such an environment, but it may be used from the GEM desktop without
    problems.

    As seen above in the synopsis there is 4 versions of the command line,
    each of which is a derivate of the first general synopsis. The 4 versions
    are shown since, depending upon which options are chosen, some arguments
    are required to be specified, most notably the requirement of the {source}
    and {destination} arguments wary. It should also be noted that limited
    checking is performed on the mixes of options - so care should be taken
    not to specify contradictory options.

    In the synopsis {source} specify where the directories and files to backup
    are located and {destination} specify where files, which match backup
    criteria, are to be copied to. If copying is to be done, during a backup
    session, a check is always made to ensure that neither of these arguments
    are equal as well as throughout the session. This means that {destination}
    may be a sub-directory of the {source} directory and that this program
    will not hang due to an endless copying loop.

    The default mode of this program is incremental backup, ie. only files
    which has been written match backup criteria. For this purpose the state
    of the "archive" flag is checked upon and if set files are copied. A flag
    is also available if a full backup is desired.

OPTIONS
    -a
        backup files via an archive utility (see ARCHIVE UTILITIES)
        This option also needs two additional arguments, {utility, line}:
        utility     is the filename of the archive utility to be used
        line        is the format of the command line
    -c
        clear archive flag status on all files without copying files.
        It does not need a {destination} argument.
    -h
        hold screen after backup, Primarily useful when called from the GEM
        desktop.
    -f  full backup, ignores the archive flag and copies everything
    -k  keep archive flag status on source files
    -l
        A list is produced of files to backup. The list format is specified
        using the compulsory {format} (see LIST FORMAT) argument. The list is
        sent to a file in the current working directory, called "dbackup.xxx".
        It does not need a {destination} argument.
    -m
        mark files for backup (ie. set archive flag on all files)
        It does not need a {destination} argument.
    -o
        copy only files which have any of the defined suffixes. The suffixes
        to be copied is specified by {suffixes}. If the list is started with a
        dot ("."), files which do not have a suffix is also copied. Suffixes
        in the list are delimited by dots eg. bak.tmp would copy the files
        ending with ".bak" or ".tmp".
    -r
        This option is only useful when the "-a" option has been specified.
        The argument {size} (Kbytes) specifies how large an archive may
        become. Any files larger than the specified size will be skipped, so
        the algorithms do not try to estimate the compression rate, but are
        rather conservative in their assumptions. Also, it assumes that an
        archive may be duplicated on the destination drive, so it may be that
        you end up with archives 50% smaller if free space on the destination
        media is scarce. The algorithm, being conservative, in this way
        ensures that no "out of memory" problems occurs and that archives
        won't become larger than the specified size, provided that, if for
        instance compression is performed, an archived file is not larger than
        it was originally. Normally archived files will be significantly
        smaller.
    -s
        This gives you a report on how much memory is needed in order to
        perform a backup. It does not need a {destination} argument.
    -t
        Normally files copied to the destination media will inherit the date &
        time stamp from the original. This option overrides this by stamping
        files with the date & time when the backup was invoked.
    -v
        verbose mode, normally progress reporting will overwrite itself, but
        with this option it will scroll for every sub-directory found in the
        source path as well as inform you of the free internal memory left in
        your machine, which is useful if you suspect that an archive utility
        is stealing memory which might cause the machine to hang if a large
        filesystem is being searched.
    -x
        This option will exclude suffixes specified by the argument
        {suffixes}. If the list is begun with a dot ("."), files which do not
        have a suffix will also be excluded. Suffixes in this list are
        delimited by dots eg. bak.tmp would exclude files foo.bak and foo.tmp

LIST FORMAT
    The {format} argument used whenever the "-l" option is specified defines
    what the list is to be composed by:

    a   file attributes     (4 character number)
    d   file modify date    (6 characters eg. 910730)
    f   filename            (path + node + suffix)
    n   node                (node + suffix excluding path)
    p   path                (path to file)
    s   size of file        (number)
    t   file modify time    (6 characters eg. 235700)
    u   unix modify time    (seconds since 1 Jan 1970)
    x   default list        (same as -f)

ARCHIVE UTILITIES
    When using the Archive utility option you have to specify the filename of
    the archive utility, with the {utility} argument. You also have to specify
    the way dbackup should call the archive utility, which is specified with
    the {line} argument. When specifying this tilde "~" is used as a special
    formating sequence, which is listed below:
        ~a<xxx>
            expands to the runtime archive name with a suffix defined by {xxx}
            eg. "~alzh" would expand to an archive filename with a suffix
            ".LZH". {xxx} must not contain a leading dot.
        ~f  expands to the files to be backup:ed
        ~~  expands to a single tilde (~)

    Please note that the {line} argument must be a single one which means that
    if it contains spaces, the argument must be within quotes.

    Arhive filenames names will be in the form:
        DBAK????.xxx
    where ???? denote a decimal sequence number. The sequence number will
    usually starts at 0001 or the next sequence number found in the
    corresponding sub-directory on the destination media of the source
    sub-directory.

    Normally when an archive utility error occurs, dbackup will report that
    files have been skipped due to an archive error and the archive flag of
    these files will be untouched. If such an error occurs it is necessary to
    run dbackup again, or otherwise the backup will not be complete.

    Since some archive utilities may introduce errors in a previous archive
    when an error occurs when it is trying to add files, I decided that if you
    had instructed dbackup to do a FULL BACKUP the sequence number will be
    increased between every call to the archive utility. This means that this
    problem will not occur during such sessions, but they still can happen if
    you're doing INCREMENTAL BACKUP.

    Below I list some {line} arguments for some of the common archive
    utilities in use:
        zoo   V2.1:     "ah: ~azoo ~f"
        lharc V2.01b:   "a -a+ ~alzh ~f"

    Since ARC doesn't like hidden or system files it is not possible to use
    this utility. This problem also exists with some versions of LHarc. I also
    recommend users of LHarc V2.01b to restrict sizes of archives to below
    800Kbytes or so, because when I was testing this utility with dbackup I
    found that LHarc V2.01b suddenly doubled the size of an archive when it
    reached the 1Mbyte mark. When using dbackup with "-r720", though, I did
    not encounter this problem.

RESTRICTED LICENCE
    See the "LICENCE" file for details

BUGS
    When using dbackup to copy files it doesn't try to copy as much as
    possible to a disk before it asks the user to swap disks, which means that
    you probably have to cycle through disks whenever prompted to swap disks.
    Users who want to store backups on 720 Kbyte disks are therefore
    recommended to use a dedicated floppy disk backup program eg. Turtle.
    This problem is not present when using the "-a" option, though.

    If you plan to use this program with the "-a" option I recommend that you
    use "-x" to exclude all files with suffixes known to indicate compressed
    archives ie. ".ARC", ".LZH" etc and with a second pass use the "-o" with
    the same list to copy the files. This will speedup the backup process
    considerably! Also, when about to do a FULL BACKUP, it is probably best to
    "-m" mark source files before backing them up so that if a fatal error
    occurs you can simply re-start the process, otherwise it would be rather
    difficult to know which files were archived and which were not.

AUTHOR
    Andrew Olausson, Gothenburg, Sweden
    FIDONET:    2:203/203.2
    INTERNET:    [e-mail]
    INTERNET:   [e-mail]