ADB(1) UNIX Programmer's Manual ADB(1)
S
\bSY
\bYN
\bNO
\bOP
\bPS
\bSI
\bIS
\bS
a
\bad
\bdb
\bb [-
\b-w
\bw] [ -
\b-k
\bk ] [ -
\b-I
\bIdir ] [ objfil [ corfil ] ]
D
\bDE
\bES
\bSC
\bCR
\bRI
\bIP
\bPT
\bTI
\bIO
\bON
\bN
_
\bA_
\bd_
\bb 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.
_
\bO_
\bb_
\bj_
\bf_
\bi_
\bl is normally an executable program file, preferably
containing a symbol table; if not then the symbolic features
of _
\ba_
\bd_
\bb cannot be used although the file can still be exam-
ined. The default for _
\bo_
\bb_
\bj_
\bf_
\bi_
\bl is a
\ba.
\b.o
\bou
\but
\bt.
\b. _
\bC_
\bo_
\br_
\bf_
\bi_
\bl is assumed to
be a core image file produced after executing _
\bo_
\bb_
\bj_
\bf_
\bi_
\bl; the
default for _
\bc_
\bo_
\br_
\bf_
\bi_
\bl is c
\bco
\bor
\bre
\be.
\b.
Requests to _
\ba_
\bd_
\bb are read from the standard input and
responses are to the standard output. If the -
\b-w
\bw flag is
present then both _
\bo_
\bb_
\bj_
\bf_
\bi_
\bl and _
\bc_
\bo_
\br_
\bf_
\bi_
\bl are created if necessary
and opened for reading and writing so that files can be
modified using _
\ba_
\bd_
\bb.
The -
\b-k
\bk option makes _
\ba_
\bd_
\bb do UNIX kernel memory mapping; it
should be used when _
\bc_
\bo_
\br_
\be is a UNIX crash dump or /_
\bd_
\be_
\bv/_
\bm_
\be_
\bm.
The -
\b-I
\bI option specifies a directory where files to be read
with $< or $<< (see below) will be sought; the default is
/_
\bu_
\bs_
\br/_
\bl_
\bi_
\bb/_
\ba_
\bd_
\bb.
_
\bA_
\bd_
\bb ignores QUIT; INTERRUPT causes return to the next _
\ba_
\bd_
\bb
In general requests to _
\ba_
\bd_
\bb are of the form
[_
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs] [, _
\bc_
\bo_
\bu_
\bn_
\bt] [_
\bc_
\bo_
\bm_
\bm_
\ba_
\bn_
\bd] [;]
If _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs is present then _
\bd_
\bo_
\bt is set to _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs. Initially
_
\bd_
\bo_
\bt is set to 0. For most commands _
\bc_
\bo_
\bu_
\bn_
\bt specifies how many
times the command will be executed. The default _
\bc_
\bo_
\bu_
\bn_
\bt is 1.
_
\bA_
\bd_
\bd_
\br_
\be_
\bs_
\bs and _
\bc_
\bo_
\bu_
\bn_
\bt are expressions.
The interpretation of an address depends on the context it
is used in. 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
/_
\bd_
\be_
\bv/_
\bm_
\be_
\bm to interactive examine and/or modify memory the
maps are set to map the kernel virtual addresses which start
at 0x80000000 (on the VAX). ADDRESSES.
Printed 7/9/88 April 29, 1985 1
ADB(1) UNIX Programmer's Manual ADB(1)
E
\bEX
\bXP
\bPR
\bRE
\bES
\bSS
\bSI
\bIO
\bON
\bNS
\bS
.
\b. The value of _
\bd_
\bo_
\bt.
+ The value of _
\bd_
\bo_
\bt incremented by the current incre-
^ The value of _
\bd_
\bo_
\bt decremented by the current incre-
" The last _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs typed.
_
\bi_
\bn_
\bt_
\be_
\bg_
\be_
\br
A number. The prefixes 0o and 0O ("zero oh") 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 _
\bd_
\be_
\bf_
\ba_
\bu_
\bl_
\bt _
\br_
\ba_
\bd_
\bi_
\bx is used; see the $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
_
\bi_
\bn_
\bt_
\be_
\bg_
\be_
\br.
\b._
\bf_
\br_
\ba_
\bc_
\bt_
\bi_
\bo_
\bn
A 32 bit floating point number.
'_
\bc_
\bc_
\bc_
\bc' The ASCII value of up to 4 characters. \ may be used
< _
\bn_
\ba_
\bm_
\be The value of _
\bn_
\ba_
\bm_
\be, which is either a variable name or
a register name. _
\bA_
\bd_
\bb maintains a number of variables
(see VARIABLES) named by single letters or digits.
If _
\bn_
\ba_
\bm_
\be is a register name then the value of the
register is obtained from the system header in _
\bc_
\bo_
\br_
\b-
_
\bf_
\bi_
\bl. The register names are those printed by the $r
_
\bs_
\by_
\bm_
\bb_
\bo_
\bl A _
\bs_
\by_
\bm_
\bb_
\bo_
\bl is a sequence of upper or lower case
letters, underscores or digits, not starting with a
digit. The backslash character \
\b\ may be used to
escape other characters. The value of the _
\bs_
\by_
\bm_
\bb_
\bo_
\bl is
taken from the symbol table in _
\bo_
\bb_
\bj_
\bf_
\bi_
\bl. An initial _
will be prepended to _
\bs_
\by_
\bm_
\bb_
\bo_
\bl if needed.
_ _
\bs_
\by_
\bm_
\bb_
\bo_
\bl
In C, the `true name' of an external symbol begins
with _. It may be necessary to utter this name to
distinguish it from internal or hidden variables of a
Printed 7/9/88 April 29, 1985 2
ADB(1) UNIX Programmer's Manual ADB(1)
_
\br_
\bo_
\bu_
\bt_
\bi_
\bn_
\be.
\b._
\bn_
\ba_
\bm_
\be
The address of the variable _
\bn_
\ba_
\bm_
\be in the specified C
routine. Both _
\br_
\bo_
\bu_
\bt_
\bi_
\bn_
\be and _
\bn_
\ba_
\bm_
\be are _
\bs_
\by_
\bm_
\bb_
\bo_
\bl_
\bs. If _
\bn_
\ba_
\bm_
\be
is omitted the value is the address of the most
recently activated C stack frame corresponding to
_
\br_
\bo_
\bu_
\bt_
\bi_
\bn_
\be. (This form is currently broken on the VAX;
local variables can be examined only with _
\bd_
\bb_
\bx(1).)
(_
\be_
\bx_
\bp) The value of the expression _
\be_
\bx_
\bp.
M
\bMo
\bon
\bna
\bad
\bdi
\bic
\bc o
\bop
\bpe
\ber
\bra
\bat
\bto
\bor
\brs
\bs
*_
\be_
\bx_
\bp The contents of the location addressed by _
\be_
\bx_
\bp in _
\bc_
\bo_
\br_
\b-
@_
\be_
\bx_
\bp The contents of the location addressed by _
\be_
\bx_
\bp in
_
\bo_
\bb_
\bj_
\bf_
\bi_
\bl.
-_
\be_
\bx_
\bp Integer negation.
~_
\be_
\bx_
\bp Bitwise complement.
#_
\be_
\bx_
\bp Logical negation.
D
\bDy
\bya
\bad
\bdi
\bic
\bc o
\bop
\bpe
\ber
\bra
\bat
\bto
\bor
\brs
\bs are left associative and are less binding
_
\be_
\b1+_
\be_
\b2 Integer addition.
_
\be_
\b1-_
\be_
\b2 Integer subtraction.
_
\be_
\b1*_
\be_
\b2 Integer multiplication.
_
\be_
\b1%_
\be_
\b2 Integer division.
_
\be_
\b1&_
\be_
\b2 Bitwise conjunction.
_
\be_
\b1|_
\be_
\b2 Bitwise disjunction.
_
\be_
\b1#_
\be_
\b2 _
\bE_
\b1 rounded up to the next multiple of _
\be_
\b2.
C
\bCO
\bOM
\bMM
\bMA
\bAN
\bND
\bDS
\bS
Most commands consist of a verb followed by a modifier or
list of modifiers. The following verbs are available. (The
commands `?' and `/' may be followed by `*'; see ADDRESSES
?_
\bf Locations starting at _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs in _
\bo_
\bb_
\bj_
\bf_
\bi_
\bl are printed
according to the format _
\bf. _
\bd_
\bo_
\bt is incremented by the
sum of the increments for each format letter (q.v.).
/_
\bf Locations starting at _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs in _
\bc_
\bo_
\br_
\bf_
\bi_
\bl are printed
Printed 7/9/88 April 29, 1985 3
ADB(1) UNIX Programmer's Manual ADB(1)
according to the format _
\bf and _
\bd_
\bo_
\bt is incremented as for
=_
\bf The value of _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs itself is printed in the styles
indicated by the format _
\bf. (For i
\bi format `?' is
printed for the parts of the instruction that reference
A _
\bf_
\bo_
\br_
\bm_
\ba_
\bt 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 _
\bd_
\bo_
\bt is incre-
mented 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.
o
\bo 2 Print 2 bytes in octal. All octal numbers output
by _
\ba_
\bd_
\bb are preceded by 0.
O
\bO 4 Print 4 bytes in octal.
q
\bq 2 Print in signed octal.
Q
\bQ 4 Print long signed octal.
D
\bD 4 Print long decimal.
x
\bx 2 Print 2 bytes in hexadecimal.
X
\bX 4 Print 4 bytes in hexadecimal.
u
\bu 2 Print as an unsigned decimal number.
U
\bU 4 Print long unsigned decimal.
f
\bf 4 Print the 32 bit value as a floating point number.
F
\bF 8 Print double floating point.
b
\bb 1 Print the addressed byte in octal.
c
\bc 1 Print the addressed character.
C
\bC 1 Print the addressed character using the standard
escape convention where control characters are
printed as ^X and the delete character is printed
s
\bs _
\bn Print the addressed characters until a zero char-
S
\bS _
\bn Print a string using the ^_
\bX escape convention (see
C
\bC above). _
\bn is the length of the string including
Y
\bY 4 Print 4 bytes in date format (see _
\bc_
\bt_
\bi_
\bm_
\be(3)).
i
\bi n Print as machine instructions. _
\bn 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 respec-
a
\ba 0 Print the value of _
\bd_
\bo_
\bt in symbolic form. Symbols
are checked to ensure that they have an appropri-
ate type as indicated below.
/ local or global data symbol
? local or global text symbol
Printed 7/9/88 April 29, 1985 4
ADB(1) UNIX Programmer's Manual ADB(1)
= local or global absolute symbol
p
\bp 4 Print the addressed value in symbolic form using
the same rules for symbol lookup as a
\ba.
t
\bt 0 When preceded by an integer tabs to the next
appropriate tab stop. For example, 8
\b8t
\bt moves to
the next 8-space tab stop.
Print the enclosed string.
^
\b^ _
\bD_
\bo_
\bt is decremented by the current increment.
+ _
\bD_
\bo_
\bt is incremented by 1. Nothing is printed.
- _
\bD_
\bo_
\bt is decremented by 1. Nothing is printed.
Repeat the previous command with a _
\bc_
\bo_
\bu_
\bn_
\bt of 1.
[?
\b?/
\b/]l
\bl _
\bv_
\ba_
\bl_
\bu_
\be _
\bm_
\ba_
\bs_
\bk
Words starting at _
\bd_
\bo_
\bt are masked with _
\bm_
\ba_
\bs_
\bk and compared
with _
\bv_
\ba_
\bl_
\bu_
\be until a match is found. If L
\bL is used then
the match is for 4 bytes at a time instead of 2. If no
match is found then _
\bd_
\bo_
\bt is unchanged; otherwise _
\bd_
\bo_
\bt is
set to the matched location. If _
\bm_
\ba_
\bs_
\bk is omitted then
[?
\b?/
\b/]w
\bw _
\bv_
\ba_
\bl_
\bu_
\be ...
Write the 2-byte _
\bv_
\ba_
\bl_
\bu_
\be into the addressed location. If
the command is W
\bW, write 4 bytes. Odd addresses are not
allowed when writing to the subprocess address space.
[?
\b?/
\b/]m
\bm _
\bb_
\b1 _
\be_
\b1 _
\bf_
\b1[?
\b?/
\b/]
New values for (_
\bb_
\b1, _
\be_
\b1, _
\bf_
\b1) are recorded. If less than
three expressions are given then the remaining map
parameters are left unchanged. If the `?' or `/' is
followed by `*' then the second segment (_
\bb_
\b2,_
\be_
\b2,_
\bf_
\b2) of
the mapping is changed. If the list is terminated by
`?' or `/' then the file (_
\bo_
\bb_
\bj_
\bf_
\bi_
\bl or _
\bc_
\bo_
\br_
\bf_
\bi_
\bl respec-
tively) is used for subsequent requests. (So that, for
example, `/m?' will cause `/' to refer to _
\bo_
\bb_
\bj_
\bf_
\bi_
\bl.)
_
\bD_
\bo_
\bt is assigned to the variable or register named.
!
\b! A shell (/bin/sh) is called to read the rest of the
$_
\bm_
\bo_
\bd_
\bi_
\bf_
\bi_
\be_
\br
Miscellaneous commands. The available _
\bm_
\bo_
\bd_
\bi_
\bf_
\bi_
\be_
\br_
\bs are:
<
\b<_
\bf Read commands from the file _
\bf. If this command is
Printed 7/9/88 April 29, 1985 5
ADB(1) UNIX Programmer's Manual ADB(1)
executed in a file, further commands in the file
are not seen. If _
\bf is omitted, the current input
stream is terminated. If a _
\bc_
\bo_
\bu_
\bn_
\bt is given, and is
zero, the command will be ignored. The value of
the count will be placed in variable _
\b9 before the
first command in _
\bf is executed.
<
\b<<
\b<_
\bf Similar to <
\b< except it can be used in a file of
commands without causing the file to be closed.
Variable _
\b9 is saved during the execution of this
command, and restored when it completes. There is
a (small) finite limit to the number of <
\b<<
\b< files
that can be open at once.
>
\b>_
\bf Append output to the file _
\bf, which is created if
it does not exist. If _
\bf is omitted, output is
returned to the terminal.
?
\b? Print process id, the signal which caused stoppage
or termination, as well as the registers as $
\b$r
\br.
This is the default if _
\bm_
\bo_
\bd_
\bi_
\bf_
\bi_
\be_
\br is omitted.
r
\br Print the general registers and the instruction
addressed by p
\bpc
\bc. _
\bD_
\bo_
\bt is set to p
\bpc
\bc.
b
\bb Print all breakpoints and their associated counts
c
\bc C stack backtrace. If _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs is given then it is
taken as the address of the current frame instead
of the contents of the frame-pointer register. If
C
\bC is used then the names and (32 bit) values of
all automatic and static variables are printed for
each active function. (broken on the VAX). If
_
\bc_
\bo_
\bu_
\bn_
\bt is given then only the first _
\bc_
\bo_
\bu_
\bn_
\bt frames
d
\bd Set the default radix to _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs and report the
new value. Note that _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs is interpreted in
the (old) current radix. Thus "10$d" never
changes the default radix. To make decimal the
default radix, use "0t10$d".
e
\be The names and values of external variables are
w
\bw Set the page width for output to _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs (default
s
\bs Set the limit for symbol matches to _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs
o
\bo All integers input are regarded as octal.
q
\bq Exit from _
\ba_
\bd_
\bb.
v
\bv Print all non zero variables in octal.
m
\bm Print the address map.
p
\bp (_
\bK_
\be_
\br_
\bn_
\be_
\bl _
\bd_
\be_
\bb_
\bu_
\bg_
\bg_
\bi_
\bn_
\bg) Change the current kernel
memory mapping to map the designated u
\bus
\bse
\ber
\br s
\bst
\btr
\bru
\buc
\bc-
\b-
t
\btu
\bur
\bre
\be to the address given by the symbol __
\bu. The
_
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs argument is the address of the user's user
page table entries (on the VAX).
:
\b:_
\bm_
\bo_
\bd_
\bi_
\bf_
\bi_
\be_
\br
Printed 7/9/88 April 29, 1985 6
ADB(1) UNIX Programmer's Manual ADB(1)
Manage a subprocess. Available modifiers are:
b
\bb_
\bc Set breakpoint at _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs. The breakpoint is exe-
cuted _
\bc_
\bo_
\bu_
\bn_
\bt-1 times before causing a stop. Each
time the breakpoint is encountered the command _
\bc
is executed. If this command is omitted or sets
_
\bd_
\bo_
\bt to zero then the breakpoint causes a stop.
d
\bd Delete breakpoint at _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs.
r
\br Run _
\bo_
\bb_
\bj_
\bf_
\bi_
\bl as a subprocess. If _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs is given
explicitly then the program is entered at this
point; otherwise the program is entered at its
standard entry point. _
\bc_
\bo_
\bu_
\bn_
\bt specifies how many
breakpoints are to be ignored before stopping.
Arguments to the subprocess may be supplied on the
same line as the command. An argument starting
with < or > causes the standard input or output to
be established for the command.
c
\bc_
\bs The subprocess is continued with signal _
\bs, see
_
\bs_
\bi_
\bg_
\bv_
\be_
\bc(2). If _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs is given then the subpro-
cess is continued at this address. If no signal
is specified then the signal that caused the sub-
process to stop is sent. Breakpoint skipping is
s
\bs_
\bs As for c
\bc except that the subprocess is single
stepped _
\bc_
\bo_
\bu_
\bn_
\bt times. If there is no current sub-
process then _
\bo_
\bb_
\bj_
\bf_
\bi_
\bl is run as a subprocess as for
r
\br. In this case no signal can be sent; the
remainder of the line is treated as arguments to
k
\bk The current subprocess, if any, is terminated.
V
\bVA
\bAR
\bRI
\bIA
\bAB
\bBL
\bLE
\bES
\bS
_
\bA_
\bd_
\bb provides a number of variables. Named variables are set
initially by _
\ba_
\bd_
\bb but are not used subsequently. Numbered
variables are reserved for communication as follows.
0 The last value printed.
1 The last offset part of an instruction source.
2 The previous value of variable 1.
9 The count on the last $< or $<< command.
On entry the following are set from the system header in the
_
\bc_
\bo_
\br_
\bf_
\bi_
\bl. If _
\bc_
\bo_
\br_
\bf_
\bi_
\bl does not appear to be a c
\bco
\bor
\bre
\be file then
these values are set from _
\bo_
\bb_
\bj_
\bf_
\bi_
\bl.
b The base address of the data segment.
Printed 7/9/88 April 29, 1985 7
ADB(1) UNIX Programmer's Manual ADB(1)
m The `magic' number (0407, 0410 or 0413).
s The stack segment size.
A
\bAD
\bDD
\bDR
\bRE
\bES
\bSS
\bSE
\bES
\bS
The address in a file associated with a written address is
determined by a mapping associated with that file. Each
mapping is represented by two triples (_
\bb_
\b1, _
\be_
\b1, _
\bf_
\b1) and (_
\bb_
\b2,
_
\be_
\b2, _
\bf_
\b2) and the _
\bf_
\bi_
\bl_
\be _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs corresponding to a written
_
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs is calculated as follows.
_
\bb_
\b1<
\b__
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs<_
\be_
\b1 => _
\bf_
\bi_
\bl_
\be _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs=_
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs+_
\bf_
\b1-_
\bb_
\b1, otherwise,
_
\bb_
\b2<
\b__
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs<_
\be_
\b2 => _
\bf_
\bi_
\bl_
\be _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs=_
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs+_
\bf_
\b2-_
\bb_
\b2,
otherwise, the requested _
\ba_
\bd_
\bd_
\br_
\be_
\bs_
\bs is not legal. In some
cases (e.g. for programs with separated I and D space) the
two segments for a file may overlap. If a ?
\b? or /
\b/ is fol-
lowed by an *
\b* then only the second triple is used.
The initial setting of both mappings is suitable for normal
a
\ba.
\b.o
\bou
\but
\bt and c
\bco
\bor
\bre
\be files. If either file is not of the kind
expected then, for that file, _
\bb_
\b1 is set to 0, _
\be_
\b1 is set to
the maximum file size and _
\bf_
\b1 is set to 0; in this way the
whole file can be examined with no address translation.
S
\bSE
\bEE
\bE A
\bAL
\bLS
\bSO
\bO
cc(1), dbx(1), ptrace(2), a.out(5), core(5)
D
\bDI
\bIA
\bAG
\bGN
\bNO
\bOS
\bST
\bTI
\bIC
\bCS
\bS
`Adb' when there is no current command or format. Comments
about inaccessible files, syntax errors, abnormal termina-
tion of commands, etc. Exit status is 0, unless last com-
mand failed or returned nonzero status.
Since no shell is invoked to interpret the arguments of the
:
\b:r
\br command, the customary wild-card and variable expansions
Printed 7/9/88 April 29, 1985 8
projects / unix-history / blob