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.Dd July 5, 2023
.Dt DB_COMMAND 9
.Os
.Sh NAME
.Nm DB_COMMAND ,
.Nm DB_COMMAND_FLAGS ,
.Nm DB_SHOW_COMMAND ,
.Nm DB_SHOW_COMMAND_FLAGS ,
.Nm DB_SHOW_ALL_COMMAND ,
.Nm DB_TABLE_COMMAND ,
.Nm DB_TABLE_COMMAND_FLAGS ,
.Nm DB_ALIAS ,
.Nm DB_ALIAS_FLAGS ,
.Nm DB_SHOW_ALIAS ,
.Nm DB_SHOW_ALIAS_FLAGS ,
.Nm DB_SHOW_ALL_ALIAS ,
.Nm DB_TABLE_ALIAS ,
.Nm DB_TABLE_ALIAS_FLAGS
.Nm DB_DECLARE_TABLE ,
.Nm DB_DEFINE_TABLE ,
.Nd Extends the ddb command set
.Sh SYNOPSIS
.In ddb/ddb.h
.Fn DB_COMMAND "command_name" "command_function"
.Fn DB_COMMAND_FLAGS "command_name" "command_function" "flags"
.Fn DB_SHOW_COMMAND "command_name" "command_function"
.Fn DB_SHOW_COMMAND_FLAGS "command_name" "command_function" "flags"
.Fn DB_SHOW_ALL_COMMAND "command_name" "command_function"
.Fn DB_TABLE_COMMAND "table" "command_name" "command_function"
.Fn DB_TABLE_COMMAND_FLAGS "table" "command_name" "command_function" "flags"
.Fn DB_ALIAS "alias_name" "command_function"
.Fn DB_ALIAS_FLAGS "alias_name" "command_function" "flags"
.Fn DB_SHOW_ALIAS "alias_name" "command_function"
.Fn DB_SHOW_ALIAS_FLAGS "alias_name" "command_function" "flags"
.Fn DB_SHOW_ALL_ALIAS "alias_name" "command_function"
.Fn DB_TABLE_ALIAS "table" "alias_name" "command_function"
.Fn DB_TABLE_ALIAS_FLAGS "table" "alias_name" "command_function" "flags"
.Fn DB_DEFINE_TABLE "parent" "name" "table"
.Fn DB_DECLARE_TABLE "table"
.Sh DESCRIPTION
The
.Fn DB_COMMAND
macro adds
.Fa command_name
to the list of top-level commands.
Invoking
.Fa command_name
from ddb will call
.Fa command_function .
.Pp
The
.Fn DB_SHOW_COMMAND
and
.Fn DB_SHOW_ALL_COMMAND
macros are roughly equivalent to
.Fn DB_COMMAND
but in these cases,
.Fa command_name
is a sub-command of the ddb
.Sy show
command and
.Sy show all
command, respectively.
.Pp
The
.Fn DB_TABLE_COMMAND
macro is also similar to
.Fn DB_COMMAND
but adds the new command as a sub-command of the ddb command
.Fa table .
.Pp
The
.Fn DB_ALIAS ,
.Fn DB_SHOW_ALIAS ,
.Fn DB_SHOW_ALL_ALIAS ,
and
.Fn DB_TABLE_ALIAS
macros register the existing
.Fa command_function
under the alternative command name
.Fa alias_name .
.Pp
The _FLAGS variants of these commands allow the programmer to specify a value
for the
.Fa flag
field of the command structure.
The possible flag values are defined alongside
.Ft struct db_command
in
.In ddb/ddb.h .
.Pp
The general command syntax:
.Cm command Ns Op Li \&/ Ns Ar modifier
.Ar address Ns Op , Ns Ar count ,
translates into the following parameters for
.Fa command_function :
.Bl -tag -width Fa -offset indent
.It Fa addr
The address passed to the command as an argument.
.It Fa have_addr
A boolean value that is true if the addr field is valid.
.It Fa count
The number of quad words starting at offset
.Fa addr
that the command must process.
.It Fa modif
A pointer to the string of modifiers.
That is, a series of symbols used to pass some options to the command.
For example, the
.Sy examine
command will display words in decimal form if it is passed the modifier "d".
.El
.Pp
The
.Fn DB_DEFINE_TABLE
macro adds a new command
.Fa name
as a sub-command of the existing command table
.Fa parent .
The new command defines a table named
.Fa table
which contains sub-commands.
New commands and aliases can be added to this table by passing
.Fa table
as the first argument to one of the DB_TABLE_ macros.
.Sh EXAMPLES
In your module, the command is declared as:
.Bd -literal
DB_COMMAND(mycmd, my_cmd_func)
{
	if (have_addr)
		db_printf("Calling my command with address %p\\n", addr);
}
.Ed
.Pp
An alias for this command is declared as:
.Bd -literal
DB_ALIAS(mycmd2, my_cmd_func);
.Ed
.Pp
Then, when in ddb:
.Bd -literal
.Bf Sy
db> mycmd 0x1000
Calling my command with address 0x1000
db> mycmd2 0x2500
Calling my command with address 0x2500
db>
.Ef
.Ed
.Sh SEE ALSO
.Xr ddb 4
.Sh AUTHORS
This manual page was written by
.An Guillaume Ballet Aq Mt gballet@gmail.com .