adb.1

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 1 代码 · 共 880 行 · 第 1/2 页

.\" SCCSID: @(#)adb.1	2.6	7/14/87
.TH adb 1 VAX
.SH Name
adb \- interactive C program debugger
.SH Syntax
.B adb
[\fB\-w\fR] [\fB\-k\fR] [\fB\-I\fIdir\fR\|] [\fIobjfil \fR\|[\fIcorfil\fR\|]\|]
.ds TW \v'.25m'\s+2~\s-2\v'-.25m'
.ds ST *
.ds IM \v'.1m'=\v'-.1m'\s-2\h'-.1m'>\h'.1m'\s+2
.ds LE \(<=
.ds LT \s-2<\s+2
.ds GT \s-2>\s+2
.SH Description
.NXR "adb debugger" 
.NXR "adb debugger" "od command"
.NXR "adb debugger" "core file"
.NXR "adb debugger" "options"
The
.PN adb
command is a general purpose debugging program.
It may be used to examine files and to provide
a controlled environment for the execution of UNIX programs.
.PP
The
.I objfil
is normally an executable program file, preferably
containing a symbol table.  If it does not contain a
symbol table then the symbolic features of
.PN adb
cannot be used.  However, the file can still be examined.
The default for
.I objfil
is
.PN a.out .
The
.I corfil
is assumed to be a core image file produced after executing
.IR objfil ;
the default for
.I corfil
is
.I core.
.PP
Requests to
.PN adb
are read from the standard input and responses are to the standard output.
If the
.B \-w
flag is present then both
.I objfil
and
.I corfil
are created if necessary and opened for reading and writing
so that files can be modified using
.PN adb .
.PP
The \fB\-k\fP option makes 
.PN adb
do UNIX kernel memory
mapping; it should be used when \fIcore\fP is a UNIX crash dump
or 
.PN /dev/mem .
.PP
The \fB\-I\fP option specifies a directory where files to be read
with
.PN $<
or
.PN $<<
(see the EXPRESSIONS section) are sought.  The default directory is
.PN /usr/lib/adb .
.PP
The
.PN adb
command ignores QUIT; INTERRUPT causes return to the next
.PN adb
command.
.PP
In general requests to
.PN adb
are of the form
.PP
.if n .ti 16
.if t .ti 1.6i
[\|\fIaddress\fR\|]  [\|,
.IR count \|]
[\|\fIcommand\fR\|] [\|;\|]
.PP
If
.I address
is present then
.I  dot
is set to
.IR address .
Initially
.I dot
is set to 0.  For most commands
.I count
specifies how many times the command is executed.  The default
.I count
is 1.
.I Address
and
.I count
are expressions.
.PP
The interpretation of an address depends on its context.
If a subprocess is being debugged then addresses are interpreted
in the usual way in the address space of the subprocess.
If the operating system is being debugged either post-mortem or using
the special file
.PN /dev/mem
to interactive examine and/or modify memory the maps are set to map
the kernel virtual addresses which start at 0x80000000.
For further details of address mapping, see
ADDRESSES.
.SH Expressions
.NXR "adb debugger" "expressions"
.TP 12
.B .
The value of
.IR dot .
.TP 12
+
The value of
.I dot
incremented by the current increment.
.TP 12
^
The value of
.I dot
decremented by the current increment.
.TP 12
"
The last
.I address
typed.
.TP 12
.I integer
A number.  The prefixes 0o and 0O (\*(lqzero oh\*(rq) force interpretation
in octal radix; the prefixes 0t and 0T force interpretation in
decimal radix; the prefixes 0x and 0X force interpretation in
hexadecimal radix.  Thus 0o20 = 0t16 = 0x10 = sixteen.
If no prefix appears, then the
.I default\ radix
is used; see the
.I $d
command.  The default radix is initially hexadecimal.
The hexadecimal digits are 0123456789abcdefABCDEF with the obvious
values.  Note that a hexadecimal number whose most significant
digit would otherwise be an alphabetic character must have a 0x
(or 0X) prefix (or a leading zero if the default radix is hexadecimal).
.TP 12
.IB integer . fraction
A 32 bit floating point number.
.TP 12
.I \'cccc\|\'
The ASCII value of up to 4 characters.
.TP 12
.I \*(LT name
The value of
.IR name ,
which is either a variable name or a register name.
The
.PN adb
debugger
maintains a number of variables (see
VARIABLES)
named by single letters or digits.
If
.I name
is a register name then the value of the register is obtained from
the system header in
.IR corfil .
The register names are those printed by the
.I $r
command.
.TP 12
.I symbol
A
.I symbol
is a sequence of upper or lower case letters, underscores or
digits, not starting with a digit.  The backslash character
.B \e 
may be used to escape other characters.  The value of the
.I symbol
is taken from the symbol table in
.IR objfil .
An initial underscore (_) will be prepended to
.I symbol
if needed.
.TP
.I _ symbol
In C, the true name of an external symbol begins with _.
It may be necessary to use this name to distinguish it
from internal or hidden variables of a program.
.TP 12
.IB routine . name
The address of the variable
.I name
in the specified C routine.  Both
.I routine
and
.I name
are
.IR symbols .
If
.I name
is omitted the value is the address of the most recently activated C stack frame
corresponding to
.IR routine .
This form is currently broken on the VAX; local variables can be examined
only with
.MS dbx 1 .
.TP 12
.RI ( exp \|)
The value of the expression
.IR exp .
.PP
.B  "Monadic\ operators"
.NXR "adb debugger" "monadic operators"
.TP 12
.RI \*(ST exp
The contents of the location addressed by
.I exp
in
.IR corfil .
.TP 12
.RI @ exp
The contents of the location addressed by
.I exp
in
.IR objfil .
.TP 12
.RI \- exp
Integer negation.
.TP 12
.RI \*(TW exp
Bitwise complement.
.TP 12
.RI # exp
Logical negation.
.PP
.tr ''
.B  "Dyadic\ operators"
are left associative and are less binding than monadic operators.
.NXR "adb debugger" "dyadic operators"
.TP 12
.IR e1 + e2
Integer addition.
.TP 12
.IR e1 \- e2
Integer subtraction.
.TP 12
.IR e1 \*(ST e2
Integer multiplication.
.TP 12
.IR e1 % e2
Integer division.
.TP 12
.IR e1 & e2
Bitwise conjunction.
.TP 12
.IR e1 | e2
Bitwise disjunction.
.TP 12
.IR e1 # e2
.I E1
rounded up to the next multiple of
.IR e2 .
.DT
.SH Commands
.NXR "adb debugger" "command list"
Most commands consist of a verb followed by a modifier or list of modifiers.
The following verbs are available.
The commands question mark (?) and slash (/) may be followed by
an asterisk (*); see the 
ADDRESSES section
for further details.
.TP 12
.RI ? f
Locations starting at
.I address
in
.I objfil
are printed according to the format
.IR f .
.I dot
is incremented by the sum of the increments for each format letter. 
.TP
.RI / f
Locations starting at
.I address
in
.I corfil
are printed according to the format
.I f
and
.I dot
is incremented as for question mark (?).
.TP
.RI  = f
The value of
.I address
itself is printed in the styles indicated by the format
.IR f .
(For
.B i 
format, the question mark (?) is printed for the parts of the
instruction that reference subsequent words.)
.PP
A
.I format
consists of one or more characters that specify a style of printing.
Each format character may be preceded by a decimal integer
that is a repeat count for the format character.
While stepping through a format,
.I dot
is incremented by the amount given for each format letter.
If no format is given then the last format is used.
The format letters available are as follows:
.TP 12
.BR o 2
Print 2 bytes in octal.  All octal numbers output by
.PN adb
are preceded by 0.
.br
.ns
.TP
.BR O 4
Print 4 bytes in octal.
.br
.ns
.TP
.BR q 2
Print in signed octal.
.br
.ns
.TP
.BR Q 4
Print long signed octal.
.br
.ns
.TP
.BR d 2
Print in decimal.
.br
.ns
.TP
.BR D 4
Print long decimal.
.br
.ns
.TP
.BR x 2
Print 2 bytes in hexadecimal.
.br
.ns
.TP
.BR X 4
Print 4 bytes in hexadecimal.
.br
.ns
.TP
.BR u 2
Print as an unsigned decimal number.
.br
.ns
.TP
.BR U 4
Print long unsigned decimal.
.br
.ns
.TP
.BR f 4
Print the 32 bit value as a floating point number.
.br
.ns
.TP
.BR F 8
Print double floating point.
.br
.ns
.TP
.BR b 1
Print the addressed byte in octal.
.br
.ns
.TP
.BR c 1
Print the addressed character.
.br
.ns
.TP
.BR C 1
Print the addressed character using
the standard escape convention where control characters
are printed as ^X and the delete character is printed as ^?.
.br
.ns
.TP
.BI s n
Print the addressed characters until a zero character is reached.
.br
.ns
.TP
.BI S n
Print a string using the ^\fIX\fR escape convention (see the format
\fBC1\fR above).
.I n
is the length of the string including its zero terminator.
.br
.ns
.TP
.BR Y 4
Print 4 bytes in date format.  For further information, see
.MS ctime 3 .
.br
.ns
.TP
.BI i n
Print as machine instructions.
.I n
is the number of bytes occupied by the instruction.
This style of printing causes variables 1 and 2 to be set
to the offset parts of the source and destination respectively.
.br
.ns
.TP
.BR a 0
Print the value of
.I dot
in symbolic form.
Symbols are checked to ensure that they have an appropriate
type as indicated below:
.sp
.RS 12
	/	local or global data symbol
.br
	?	local or global text symbol