xref: /freebsd/sbin/ddb/ddb.8 (revision 4fd2d3b6927878771635a3628ae1623daf810d39)
1.\"-
2.\" Copyright (c) 2007 Robert N. M. Watson
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26.\" $FreeBSD$
27.\"
28.Dd 25 December, 2007
29.Dt DDB 8
30.Os
31.Sh NAME
32.Nm ddb
33.Nd Configure DDB kernel debugger properties
34.Sh SYNOPSIS
35.Nm
36.Cm script
37.Ar scriptname
38.Nm
39.Cm script
40.Ar scriptname=script
41.Nm
42.Cm scripts
43.Nm
44.Cm unscript
45.Ar scriptname
46.Nm
47.Ar pathname
48.Sh DESCRIPTION
49.Nm
50configures certain aspects of the
51.Xr DDB 4
52kernel debugger from user space that are not configured at compile-time or
53easily via
54.Xr sysctl 8
55MIB entries.
56.Pp
57To ease configuration, commands can be put in a file which is processed using
58.Nm
59as shown in the last synopsis line.
60An absolute
61.Ar pathname
62must be used.
63The file will be read line by line and applied as arguments to the
64.Nm
65utility.
66Whitespace at the beginning of lines will be ignored as will lines where the
67first non-whitespace character is #.
68.Sh SCRIPTING
69.Nm
70can be used to configure aspects of
71.Xr DDB 4
72scripting from user space; scripting support is described in more detail in
73.Xr DDB 4 .
74Each of the debugger commands is available from the command line:
75.Bl -tag -width indent
76.It Cm script Ar scriptname
77Print the script named
78.Ar scriptname .
79.It Cm script Ar scriptname=scriptvalue
80Define a script named
81.Ar scriptname ;
82as many scripts contain characters interpreted in special ways by the shell,
83it is advisable to enclose
84.Ar scriptvalue
85in quotes.
86.It Cm scripts
87List currently defined scripts.
88.It Cm unset Ar scriptname
89Delete the script named
90.Ar scriptname .
91.El
92.Sh EXAMPLES
93The following example defines a script that will execute when the kernel
94debugger is entered as a result of a break signal:
95.Bd -literal -offset indent
96ddb script kdb.enter.break="show pcpu; bt"
97.Ed
98.Pp
99The following example will delete the script:
100.Bd -literal -offset indent
101ddb unscript kdb.enter.break
102.Ed
103.Pp
104For further examples, see the
105.Xr ddb 4
106and
107.Xr textdump 4
108man pages.
109.Sh EXIT STATUS
110.Ex -std
111.Sh SEE ALSO
112.Xr ddb 4 ,
113.Xr textdump 4 ,
114.Xr sysctl 8
115.Sh HISTORY
116.Nm
117first appeared in
118.Fx 8.0 .
119.Sh AUTHORS
120.An Robert N M Watson
121.Sh BUGS
122Ideally,
123.Nm
124would not exist, as all pertinent aspects of
125.Xr ddb 4
126could be configured directly via
127.Xr sysctl 8 .
128