CHDB(7) Miscellaneous Information Manual CHDB(7)
chdb - chess database browser
chdb [ file ... ]
Chdb reads the given files of chess games (hist by default) and accepts
commands to search, play through, and display the games in these files.
If x is the name of the file, it is looked for under the names x,
x.m.out, and /lib/chess/x.m.out.
After reading the files, chdb displays a chess board, a text window
with a command line, and vertical and horizontal scroll bars along the
edges of the board. The text window holds 6 lines of information about
the game and position and, at the bottom, a command line in which to
type. The displayed text contains chess symbols--use a suitable font.
The vertical scroll bar scans through the games to select a game; the
horizontal bar then scans through the moves of the selected game. Both
scroll bars use button 1 to scan backwards, button 3 to scan forwards,
and button 2 to jump to an absolute position. With buttons 1 and 3,
the scroll bars are calibrated in units of 1 through 8 corresponding to
the ranks and files of the board. The units measure games on the ver-
tical scroll bar, ply (half-moves) on the horizontal scroll bar. For
example, clicking button 3 on the horizontal scroll bar under the d
file steps through the game two full moves.
Moves may be made on the chess board by pointing with button 1. There
are two methods to point at moves. For the first method, point at the
piece to be moved, press button 1, point to the place to move that
piece, and release button 1. In the second method, point at the place
where a piece is to move and press button 1. The smallest/least-cen-
tral piece that can move there is highlighted. Releasing button 1
without moving the mouse will make the highlighted move. Moving the
mouse to the desired piece and releasing the button will move the
Typed lines of text are echoed in the command line and executed. The
available commands are:
f n n Set the format for display of moves in the text window. The
first number is the verbosity, with 0 minimal. The second num-
ber is 0 for algebraic, 1 for English, and 2 for figurine
g n Go to the game with ordinal number n in the input files. If n
is prefixed with a + or -, it is interpreted as a relative posi-
tion in the current set of games (see below). N defaults to +1.
p n Go to whole move n in the current game. If n is prefixed with a
+ or -, it is interpreted as an offset in ply from the current
position. N defaults to +1.
k n Mark the current set of games with tag n (see patterns, below).
w type file
Write the current set of games to file. Type is either a (write
the games as text) or m (write the games in binary format suit-
able for chdb).
Patterns select subsets of the games. A pattern is one of the follow-
ing, in decreasing precedence order. Parentheses can be used for
. The current game.
* All games originally read.
'n The games previously marked with a k command with the same n.
All games in * that contain the positions that can be reached in
the specified number of plies from the current position. A
missing number is the same as zero, meaning just the current
position. Positions are matched with black/white transposi-
This pattern matches the regular expression against the various
text windows. Fields is a list of characters from the set abde-
foprw. A is for all, b for black, d for date, e for event, f
for file, o for opening, p for person (white and black), r for
result, and w for white. If multiple fields are given, the
expression is matched on the union of the specified fields. If
no field is given, p is assumed.
The set subtraction of * and the given pattern.
The set subtraction of the given patterns.
The set union of the given patterns.
The set intersection of the given patterns.
These patterns have the current set of games as an implied first
Select games that Botvinnik lost:
directory of databases.
The browser is only a prototype.
Most of the databases are protected by copyright and not distributed.