Debugging with GDB Manual (5900-1473; WDB 6.2; January 2011)

Table Of Contents
t
2
Print as integer in binary. The letter 't' stands for “two
2
.
a Print as an address, both absolute in hexadecimal and as an offset from the nearest
preceding symbol. You can use this format used to discover where (in what function)
an unknown address is located:
((gdb)) p/a 0x54320
$3 = 0x54320 <_initialize_vx+396>
c Regard as an integer and print it as a character constant.
f Regard the bits of the value as a floating point number and print using typical floating
point syntax.
For example, to print the program counter in hex (see “Registers” (page 91)), type
p/x $pc
Note that no space is required before the slash; this is because command names in GDB
cannot contain a slash.
To reprint the last value in the value history with a different format, you can use the print
command with just a format and no expression. For example, 'p/x' reprints the last value
in hex.
8.5 Examining memory
You can use the command x (for “examine”) to examine memory in any of several
formats, independent of your program data types.
x/nfu addr,
x addr, x
Use the x command to examine memory.
[n],[ f], and [u] are all optional parameters that specify how much memory to display
and how to format it; addr is an expression giving the address where you want to start
displaying memory. If you use defaults for nfu, you need not type the slash '/'. Several
commands set convenient defaults for addr.
[n], the repeat count The repeat count is a decimal integer and the
default is 1. It specifies how much memory
(counting by units u) to display.
[f], the display format The display format is one of the formats used by
print, 's' (null-terminated string), or 'i' (machine
instruction). The default is 'x' (hexadecimal)
initially. The default changes each time you use
either x or print.
[u], the unit size The unit size is any of
b Bytes.
h Halfwords (two bytes).
2. 'b' cannot be used because these format letters are also used with the x command, where 'b' stands for
“byte”; see “Examining memory” (page 80).
80 Examining Data