
TITLE INFORMATION: XWatch 
 The Logfiles Watcher 
AUTHOR INFORMATION: Karel Kubat (karel@icce.rug.nl) 
 State University of Groningen 
 Westerhaven 16, 9718 AW Groningen 
 The Netherlands 
DATE INFORMATION: 1996 

Contents 

Chapter 1: Introduction 
Chapter 2: Using xwatch 
2.1: Options to the xwatch program 
2.2: File arguments 
Chapter 3: Obtaining xwatch 
Chapter 4: Compiling xwatch 
Chapter 5: Copyright 

Chapter 1: Introduction

    XWatch is a small program that I wrote to monitor logfiles and to see
    any changes directly (instead of having to read all the logs after a
    breakin or a crash). XWatch is simply started with a few file
    arguments, and any information that appears on the files is displayed.
    With a slider you can see past information; i.e., lines that scroll in
    xwatch's window. That's all there is to it. The appearance of the
    xwatch window can furthermore be modified via command line flags or
    via an application defaults file. (Older versions of XWatch had a
    button to activate an `options' window. I removed this code, almost no-one
    uses it.)

    XWatch is incidentally my first applications with the XForms GUI
    library for X, which I can highly recommend for developers who want to
    start `X programming' but who don't want to go through the hassle of
    having to learn about intrinsics. XForms is really excellent. Congrats,
    T.C. Zhao and Mark Overmars (the latter is rumored to bootleg at a soccer
    club in his free time ;). Instructions on where and how to get the XForms
    library are in the Makefile, contained in xwatch's distribution.

Chapter 2: Using xwatch

    You typically start xwatch when activating an X session; e.g.,
    from the file which xdm uses to fire up a user's session (this file is
    normally /usr/X11/lib/X11/xdm/Xsession). The command that starts
    xwatch is something like

xwatch [options] files &

    where `options' are optional flags, files are the files to watch, and
    the ampersand character is used to start xwatch in the background. The
    files to watch are typically in the directory /var/adm/: files which
    are created by the syslog daemon (see the file syslogd.conf.SAMPLE in
    the distribution for an example).  XWatch accepts only filenames which
    are:

	o  ordinary files, no sockets, directory names,

	o  which are not binary files.

    Other files as stated on the commandline are not monitored. When any
    `non-proper' file is given on the commandline, xwatch warns about the
    file not being acceptable and deletes it from its list of names.

2.1: Options to the xwatch program

    The options are many, start xwatch without arguments to see what is
    supported. All options can also be stated in the file
    /usr/lib/X11/app-defaults/XWatch as X resources (see the file
    XWatch.ap as an example). In the following enumeration, a nr
    denotes a number:

	o  -border nr:  Specifies whether xwatch should start
        with a border. The nr must be 0 or 1. When you start xwatch
        without a border, your window manager may not be able to resize or
        even recognize it. Incidentally, this may be what you want -- I use it
        to `hide' the presence of xwatch from my window manager fvwm. 

        o  -geometry geom: Specifies the display geometry, a-la 
        other X programs. You can express the geometry in terms of WxH 
        (width by height), optionally postfixed by +X+Y (x and y offset) 
        or -X-Y (offsets relative to the lower right corner) and other 
        combinations. 

        Note that previous switches that emulated the geometry specification, 
        such as -xpos and -height, are now obsolete. Use the geometry 
        setting.

        o  -fg color and -bg color: These options define the 
        default foreground and background of the watch window.

        Note that previous switches, such as -bred and -bblue, are now 
        obsolete. 

	o  -printtime nr: Defines whether xwatch should prefix
        any info on the watched files with a timestamp. The nr can be 0 or
        zero; the timestamp is printed when nr is 1.

	o  -printname nr: Defines whether xwatch should prefix
        any info on the watched files with the filename. The nr is again a
        flag, 0 or 1.

	o  -newline nr: Defines whether xwatch should let a
        newline follow the time and/or filename stamp, so that the actual
        information is displayed on its own line.

	o  -interval nr: Defines the scanning interval.  Each nr
        seconds, xwatch will check if new information has arrived on the
        watched files. The nr may be between 1 and 30 seconds. 

	o  -fontsize nr: Defines the initial size of the display
        font.  The nr may range from 1 to 4; 1 being the smallest font and
        4 being the largest.

	o  -fontstyle nr: Defines the style of the used font. The
        nr is a number between 0 and 15 (0 being the default). Start
        xwatch without arguments or read the application defaults file to
        see what fonts the numbers choose.

	o  -firstwarnings nr: Defines whether xwatch should
        print initial warnings into the watch window.  E.g., you might like to
        set firstwarnings to zero, and then start xwatch with the file
        argument /var/adm/*.  Warnings about, e.g., utmp being a
        binary file would then be suppressed.

	o  -printversion nr: Controls whether xwatch prints its
        version number and copyright notice upon startup in the watch window.

        o  -gag text: This option, when present, prevents all lines 
        with text in them from being shown in the display window. You can 
        specify more than one string to `gag', in that case, separate the 
        strings with |.

        o  -colorstring col:string: This option causes lines that 
        contain string to be displayed using the specified color.
        The string is matched literally. 
        E.g., if you use the option -colorstring blue:connection then 
        all lines containing connection are displayed in pure blue.

        You can specify several colorstrings by separating all options with a 
        | character, as in -colorstring blue:connection|red:error. Note 
        that, for reasons of shell expansion, you should quote such options on 
        the commandline.

        o  -title name: This option sets the window title of the 
        watch window. Note that the title will only be visible when border 
        is not 0. This option may be useful if you have several XWatch 
        windows, monitoring different things.

        o  -ignore fileA|fileB|fileC|...: This option is handy if 
        you start XWatch with a wildcard file argument, but when you want 
        XWatch not to process some files. The -ignore flag removes 
        the stated files from the watchlist. Note that, for reasons of shell 
        commandline expansion, you must quote the file specification (or the 
        shell will interpret the | characters as pipes). (Thanks, Frank 
        Brokken, frank@icce.rug.nl for the code).

    Before you extensively use the options, create an application defaults
    file /usr/lib/X11/app-defaults/XWatch. You can do so by copying the
    file XWatch.ap, extracted from the archive, to
    /usr/lib/X11/app-defaults/XWatch. The comments in the distributed 
    application defaults file explain what you can configure and show 
    examples. 

    Some systems do not have the directory /usr/lib/X11/app-defaults.  In
    that case, you should create the following links:

	o  /usr/X11 should point to your X11 distribution; e.g.  to
        /usr/X11R6. That way, you always have e.g.  /usr/X11/bin, even
        after upgrading your X11 distribution. All that is needed is one new
        link.

	o  /usr/lib/X11 should point to /usr/X11/lib/X11.

    Then edit the file XWatch in the application defaults directory, and
    follow the instructions therein to define your favorite settings.  If you
    need to start xwatch incidentally with another setting, use a flag.

2.2: File arguments

    The filename arguments can optionally be followed by a color
    specification that applies only to that particular file. E.g., say you
    want to see all the files in /var/adm normally in blue text; but you
    want to see /var/adm/critical (critical messages from applications) in
    yellow and /var/adm/auth (authentification messages) in red. In that
    case, the course to follow would be:

	o  The default foreground color would be blue. You could set this
        with the flags -fg blue, or in the application
        defaults file.

	o  The color for /var/adm/critical should be yellow.  Hence, the
        first file argument would be /var/adm/critical:yellow.

	o  The color for file /var/adm/auth should be red, hence the
        second file argument would be /var/adm/auth:red.

	o  The following arguments would be the files, using the standard
        foreground (blue): /var/adm/*, without any extra color
        specifications.

    Such a commandline would cause xwatch to complain about the multiple
    presence of /var/adm/critical (once from the separate argument, and
    once from the wildcard argument) and similarly about /var/adm/auth. If
    this bothers you, turn off the initial warnings (e.g., using
    -firstwarnings 0 or in the application defaults file).

    Note that besides the color specifications for filenames, you can 
    also specify coloring for lines that match a given string in all files. 
    See the above description of the  switch -colorstring for more 
    information.

Chapter 3: Obtaining xwatch

    XWatch can be obtained at the ftp site ftp.icce.rug.nl, in the directory /pub/unix, as the file xwatch-X.YY.tar.gz.
    X.YY is the version number, e.g., 1.00. This site is the primary site,
    so check here for new versions.

    To unpack the archive, change-dir to your `sources' directory (e.g.,
    /usr/local/src) and type

tar xvzf /where/ever/you/put/it/xwatch-X.YY.tar.gz

    Next, change-dir to the unpacked subdirectory xwatch and check there.
    You will find a subdirectory src with the full sources.

Chapter 4: Compiling xwatch

    Follow these steps.

	o  You will need the XForms library and include files to compile
        xwatch.  Check the Makefile in the src subdirectory for
        two ftp sites that carry XForms for Linux. Obtain the library and
        install it.  XWatch will happily run with XForms version 0.81 or 0.88.

	o  In the src subdirectory, edit the Makefile and adjust
        some defines at the top. E.g., a make install copies the binary by
        default to /usr/local/X11/bin; adjust that if you don't like this
        behavior.

	o  Next, do a make install, followed by a make clean.

        o  Copy the file XWatch.ap from the source directory to 
        /usr/lib/X11/app-defaults/XWatch. Edit the file and state your 
        favorite settings.

        o  Next, start the program xwatch with some file arguments in 
        your logfiles directory. If you're satisfied with the appearance and 
        workings of xwatch, add the invocation to your script that starts
	an X session.

Chapter 5: Copyright

    XWatch - a tool to monitor logfiles and display new logs in an X window.  
    Copyright (C) 1995 Karel Kubat.  All rights reserved.

    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
    Free Software Foundation; either version 2 of the License, or (at your
    option) any later version.

    You may link this software with XForms (Copyright (C) by T.C. Zhao and
    Mark Overmars) and distribute the resulting binary, under the
    restrictions in clause 3 of the GPL, even though the resulting binary is
    not, as a whole, covered by the GPL. (You still need a separate license
    to do so from the owner(s) of the copyright for XForms, however).  If a
    derivative no longer requires XForms, you may use the unsupplemented GPL
    as its license by deleting this paragraph and therefore removing this
    exemption for XForms.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
