Provided by: mgdiff_1.0-30_amd64 bug

NAME

       mgdiff - Motif-based graphical file difference browser

SYNOPSIS

       mgdiff [-toolkitoption ...] [-quit] [-file name] [-args diffargs] [file1 file2]

DESCRIPTION

       Mgdiff is a graphical front end to the diff command.  It permits the user to view the
       differences between two ASCII files in context and, optionally, to write out a third file
       which is the user-defined merging of those two files.  It is inspired by a similar
       program, called gdiff, which runs only on Silicon Graphics workstations and for which
       source code is not provided.

       The program takes as arguments various flags (described in the next section) and the names
       of two files to compare.  Either filename (but not both) may be given as '-' to use
       standard input instead.

       The resulting display consists mostly of two panes of text; the one on the left is the
       first file specified and the one on the right is the second file specified.  Between and
       below the text panes are scrollbars that permit changing the visible portions of the two
       files being compared.  In addition, the program implements the Scrolled Region
       recommendations of Section 2.3.4 of the OSF/Motif Style Guide (release 1.1), meaning that
       the arrow and paging keys will work to scroll as well.  Above each text pane is the name
       of the file in that text pane and the line number in the file which is being displayed.

       The text in each of the text panes is divided into blocks of lines which are color-coded
       with one of five different colors.  This indicates that the block:

              differs between the two files

              is identical between the two files

              has been inserted in one file or the other

              is for display purposes (to match an inserted block in the other file)

              has been selected by the user (for writing to a merged file)

       These colors can be modified by the user via X resources; see the RESOURCES section of
       this manual page.  A legend display of the colors and their meanings is available using
       the Help menu.

       On the right-hand side of the display is an overview area; this shows the files in their
       entirety.  The sliders in the overview area track the lines being displayed in the text
       panes.

       At the top of the display is a Motif menu bar; those functions are discussed in the MENUS
       section of this manual page.

       Earlier versions of this program (pre 2003) only allowed the selection of the left hand
       side difference or the right hand side difference.  It also would not allow a file to be
       saved with unselected blocks.  The current version allows the user to select both sides of
       a difference by selecting blocks using the middle mouse button.  When both sides of a
       difference are selected both blocks will be saved to the merged file and marked in a
       similar manner to the way CVS marks merges that require manual resolution of conflicting
       changes.  In addition, the current version also allows saving of a merged file with
       unselected blocks.  In this case, the merged file will contain neither the left hand side
       nor the right hand side of the unselected blocks.

COMMAND LINE OPTIONS

       -toolkitoption
               These are the standard options accepted by all applications that use the X Toolkit
               Intrinsics.  See the OPTIONS section in the X(1) manual page.

       -quit   This option sets the resource Mgdiff.quitIfSame to "true".  This will cause the
               program to exit immediately without bringing up a window if the two files have no
               differences (as determined by the diff command).

       -args diffargs
               This option sets the resource Mgdiff.diffArgs to the value of the diffargs
               argument.  These flags are passed to the diff command that actually computes the
               differences between the two files.  Since any argument can be passed, it is
               possible to specify flags that cause the diff command to fail or to generate
               output in a different format that will cause mgdiff to fail.  For most versions of
               diff, only three flags make any sense.  The first is '-b'; this causes diff to
               ignore trailing blanks (spaces and tabs) and to treat all other strings of blanks
               as equivalent.  The second flag is '-w'; this ignores blanks and treats strings of
               blanks as equivalent.  The last flag is '-i'; this ignores case when comparing
               letters.

       -file name
               This command sets the resource Mgdiff.filename to the value of the name argument.
               mgdiff uses this string to display over a file read from standard input.

MENUS

       The menubar contains the following menu topics as CascadeButtons: File, View, Select,
       Options and Help.  The rest of this section discusses each menu entry, showing it's name
       and accelerator, if any.

       File

       This pulldown menu controls file access:

              Open...                       Ctrl+O

              Brings up the "Open Files" FileSelectionDialog to allow the user to open two files
              for comparison.

              Open Left...                  Ctrl+L

              Brings up the "Open File" FileSelectionDialog to allow the user to specify a file
              to open and compare with the already opened right-hand file.

              Open Right...                 Ctrl+R

              Brings up the "Open File" FileSelectionDialog to allow the user to specify a file
              to open and compare with the already opened left-hand file.

              Reload Both                   Meta+R

              Re-runs diff on both the currently opened files.

              Save As...                    Ctrl+S

              Brings up the "Save File" FileSelectionDialog to allow the user to specify an
              output file for writing the merged file; this is an application modal dialog.  The
              program will allow the user to overwrite an existing file but pops up a
              QuestionDialog to allow the user to cancel the operation if desired.  If there are
              any unselected areas of difference between the two files the user is asked whether
              they want to continue or cancel the operation.  If the user continues, the output
              file will contain none of the unselected blocks.

              Save As Left...

              Saves the merged file to the location given by the left hand side file location.
              The user will be asked if they are sure they wish the existing file to be
              overwritten. As with the "Save As", if there are any unselected areas of difference
              between the two files the user asked whether they want to continue or cancel the
              operation.  If the user continues, the output file will contain none of the data in
              the unselected blocks.

              Save As Right...

              Saves the merged file to the location given by the right hand side file location.
              The user will be asked if they are sure they wish the existing file to be
              overwritten. As with the "Save As", if there are any unselected areas of difference
              between the two files the user asked whether they want to continue or cancel the
              operation.  If the user continues, the output file will contain none of the data in
              the unselected blocks.

              Exit                          Ctrl+C

              Exits the program immediately.

       View

       This pulldown menu contains commands for moving through the files.

              Previous                      Ctrl+P

              Scrolls both file views so that the previous area of difference is
              Mgdiff.linesOfContext lines from the top of the application window.

              Next                          Ctrl+N

              Scrolls both file views so that the next area of difference is
              Mgdiff.linesOfContext lines from the top of the application window.

              Next Unselected               Ctrl+U

              Scrolls both file views so that the next unselected area of difference is
              Mgdiff.linesOfContext lines from the top of the application window.

       Select

       The two files being compared can be optionally merged into one file.  To do this, the user
       must select for each area of difference between the two files which version should be
       written to the merged file.  The menu entries in this pulldown menu allow the user to
       select or unselect differences in groups rather than individually.

              Left All

              For all areas of difference between the two files select the left-hand file
              version.

              Right All

              For all areas of difference between the two files select the right-hand file
              version.

              Unselect All

              Unselects all areas of difference in both files.

       Options

       This pulldown menu controls miscellaneous appearance and/or behavior options.

              Overview                      Ctrl+W

              This menu entry toggles the presence of the overview area on the right-hand side of
              the application window.  The default value for this toggle is controlled by a
              resource, Mgdiff.overview, which is described in the RESOURCES section.

              Horizontal Scrollbar          Ctrl+H

              This menu entry toggles the presence of the horizontal scrollbar at the bottom of
              the application window.  The default value for this toggle is controlled by a
              resource, Mgdiff.horzScrollbar, which is described in the RESOURCES section.

              Drag Scroll                   Ctrl+D

              This menu entry toggles the behaviour of the scrollbars in the application window.
              When set, dragging the slider of a scrollbar results in a immediate change in the
              view of the text being compared.  When unset, the view is only changed at the end
              of a slider drag (when the mouse button is released.)  This setting might be
              preferred on a slower X server.  The default value for this toggle is controlled by
              a resource, Mgdiff.dragScroll, which is described in the RESOURCES section.

       Help

       This pulldown menu displays commands for obtaining help on or information about mgdiff.

              Version...                    Ctrl+V

              Brings up an InformationDialog with author and version information.

              Manual Page...                Ctrl+M

              Brings up a DialogShell with a ScrolledText widget containing this manual page.
              The command for generating this is customizable via a resource, Mgdiff.manCommand,
              which is described in the RESOURCES section.

              Color Legend...               Ctrl+G

              Brings up a DialogShell which summarizes the use of color in encoding the types of
              differences between the two files being compared.

OTHER DISPLAYS/CONTROLS

       You can move directly to a particular spot in the two files by using BDrag in the overview
       area.

       The program uses what the OSF/Motif Style Guide calls "multiple selection" to select
       individual blocks for writing to a merged file.  Clicking BSelect on an unselected block
       adds it to the list of selected blocks.  Clicking BSelect on a selected block removes it
       from the list of selected blocks.  In addition, Clicking BSelect on an unselected block
       which is opposite a selected block (in the other text panes) removes the selected block
       from the list of selected blocks.

       The numbers in the small boxes next to the file names are the line numbers of the lines at
       the top of the text panes.

WIDGETS

       What follows is the hierarchy of Motif widgets, as generated by editres(1).  The
       hierarchical structure of the widget tree is reflected in the indentation.  Each line
       consists of the widget class name followed by the widget instance name.  This information
       might be useful if you wish to customize the appearance of the program via resource
       settings.

       Mgdiff  mgdiff
            XmMainWindow  mainw
                 XmSeparatorGadget  MainWinSep1
                 XmSeparatorGadget  MainWinSep2
                 XmSeparatorGadget  MainWinSep3
                 XmRowColumn  menubar
                      XmCascadeButtonGadget  button_0
                      XmCascadeButtonGadget  button_1
                      XmCascadeButtonGadget  button_2
                      XmCascadeButtonGadget  button_3
                      XmCascadeButtonGadget  button_4
                      XmMenuShell  popup_file_menu
                           XmRowColumn  select_menu
                                XmPushButtonGadget  button_0
                                XmPushButtonGadget  button_1
                                XmSeparatorGadget  separator_0
                                XmPushButtonGadget  button_2
                           XmRowColumn  file_menu
                                XmPushButtonGadget  button_0
                                XmPushButtonGadget  button_1
                                XmPushButtonGadget  button_2
                                XmPushButtonGadget  button_3
                                XmPushButtonGadget  button_4
                                XmSeparatorGadget  separator_0
                                XmPushButtonGadget  button_5
                                XmPushButtonGadget  button_6
                                XmSeparatorGadget  separator_1
                                XmPushButtonGadget  button_7
                           XmRowColumn  options_menu
                                XmToggleButtonGadget  button_0
                                XmToggleButtonGadget  button_1
                                XmToggleButtonGadget  button_2
                           XmRowColumn  help_menu
                                XmPushButtonGadget  button_0
                                XmPushButtonGadget  button_1
                                XmPushButtonGadget  button_2
                           XmRowColumn  view_menu
                                XmPushButtonGadget  button_0
                                XmPushButtonGadget  button_1
                                XmPushButtonGadget  button_2
                 XmForm  form1
                      XmFrame  frame1
                           XmForm  form3
                                XmScrollBar  sbl
                                XmDrawingArea  dam
                                XmScrollBar  sbr
                      XmFrame  frame2
                           XmForm  form4
                                XmForm  form2
                                     XmScrollBar  sb
                                     XmForm  form21
                                          XmFrame  frame3
                                               XmLabel  fnamel
                                          XmFrame  frame31
                                               XmTextField  linenuml
                                     XmForm  form22
                                          XmFrame  frame4
                                               XmLabel  fnamer
                                          XmFrame  frame41
                                               XmTextField  linenumr
                                     XmDrawingArea  textl
                                     XmDrawingArea  textr
                                XmScrollBar  sbh
            XmDialogShell  version_popup
                 XmMessageBox  version
                      XmLabelGadget  symbol
                      XmLabelGadget
                      XmSeparatorGadget  separator
                      XmPushButtonGadget  OK
                      XmPushButtonGadget  Cancel
                      XmPushButtonGadget  Help
            XmDialogShell  manualpage_popup
                 XmForm  manualpage
                      XmPanedWindow  pane
                           XmScrolledWindow  help_textSW
                                XmScrollBar  vbar
                                XmText  help_text
                           XmForm  form2a
                                XmPushButton  OK
                           XmSash  sash
                           XmSeparatorGadget  separator
                           XmSash  sash
                           XmSeparatorGadget  separator
            XmDialogShell  legend_popup
                 XmForm  legend
                      XmPanedWindow  pane
                           XmRowColumn  rc
                                XmLabel  label1
                                XmLabel  label2
                                XmLabel  label3
                                XmLabel  label4
                                XmLabel  label5
                           XmForm  form2a
                                XmPushButton  OK
                           XmSash  sash
                           XmSeparatorGadget  separator
                           XmSash  sash
                           XmSeparatorGadget  separator
            XmDialogShell  werror_popup
                 XmMessageBox  werror
                      XmLabelGadget  symbol
                      XmLabelGadget
                      XmSeparatorGadget  separator
                      XmPushButtonGadget  OK
                      XmPushButtonGadget  Cancel
                      XmPushButtonGadget  Help

X RESOURCES

       Mgdiff.diffForeground:   black

       Mgdiff.diffBackground:   yellow

       These colors are for blocks which differ between files.

       Mgdiff.sameForeground:   black

       Mgdiff.sameBackground:   grey

       These colors are for blocks which are identical between files.

       Mgdiff.insertForeground: black

       Mgdiff.insertBackground: orange

       These colors are for blocks which have been inserted in one file.

       Mgdiff.blankForeground:  black

       Mgdiff.blankBackground:  grey66

       These colors are for blocks which are for display purposes.

       Mgdiff.selectForeground: black

       Mgdiff.selectBackground: light slate blue

       These colors are for blocks which have been selected by the user.

       Mgdiff.font:             7x13bold

       Font for displaying text blocks.

       Mgdiff.dragScroll:       true

       Set to true if scrollbar dragging should cause immediate changes in the viewed text, and
       false if the view should only change after the scrollbar has been moved.

       Mgdiff.overview:         true

       Set to true if the file overview section should appear.

       Mgdiff.horzScrollbar:    true

       Set to true if the horizontal scrollbar should appear.

       Mgdiff.linesOfContext:   3

       Number of lines that should appear above a difference block gotten to using the Previous
       or Next commands.  Should be greater or equal to zero.

       Mgdiff.manCommand:       (man mgdiff | col -b) 2>&1

       The command (or pipeline) used to produce a formatted manual page without escape codes.

       Mgdiff.diffCommand:      diff

       The diff(1) compatible command to use for calculating differences between text files.

       Mgdiff.diffArgs:

       The arguments to be provided to the diff command.  This resource can also be set via the
       -args command line option.

       Mgdiff.quitIfSame:       false

       If the two files have no differences (as determined by the diff command) then exit
       immediately without bringing up a window.  This resource can also be set to "true" via the
       -quit command line option.

       Mgdiff.filename:         (stdin)

       mgdiff uses this string to display over a file read from standard input.  This resource
       can also be set via the -file command line option.

DIAGNOSTICS

       Returns the exit status generated by the diff command.  This is usually 0 for no
       differences, 1 for some differences and 2 for errors.

SEE ALSO

       diff(1), X(1)

RESTRICTIONS

       Using BDrag in the overview area doesn't work well when drag scrolling is turned off.

       Doesn't support monochrome displays.

       Input lines longer than BUFSIZ (see /usr/include/stdio.h) are silently truncated.

       The code for parsing and passing arguments to the diff command assumes arguments are
       delimited by white space and does not do any quote processing.

COPYRIGHT

       Copyright (c) 1994, Daniel Williams
       Copyright (c) 2003, Erik de Castro Lopo
       See X (1) for a full statement of rights and permissions.

AUTHORS

       Daniel Williams (dan@sass.com)
       Erik de Castro Lopo (erikd AT mega-nerd DOT com) added "Save as Left/Right" and saving
       both and neither sides.

ACKNOWLEDGEMENTS

       To Andrew C. Myers for writing gdiff.

                                                                                       MGDIFF(1x)