INFORMATION ABOUT ADB INTERNALS
23 August 1988, Chris Torek
(This file is incomplete.)
Adb has a simplified, and slightly extended, version of printf,
called adbprintf(). adbprintf() conversion specifiers are introduced by
the usual `%' escape. (Beware of SCCS eating 5 and escapes.) The
format of a conversion-specifier is:
[flags] [width] [`.' precision] conversion-character
The default width is 0; the default precision is -1. The available
flags are `-', for right adjustment within the field, and `+', which
forces a sign on numeric conversions. If the result of a conversion
is narrower than the specified width, it is passed on the right (or
left if `-') with blanks. If a precision is given, and is not negative,
the result of a conversion will be truncated after precision characters.
Width and precision may be given as `*', in which case they are taken
from an integer argument a la printf().
The conversion-characters, and the types they expect, are:
d prints an hword_t value as a signed decimal integer.
D prints an expr_t value as a signed decimal integer.
u prints an hword_t value as an unsigned decimal integer.
U prints an expr_t value as an unsigned decimal integer.
q prints an hword_t value as a signed octal integer.
Q prints an expr_t value as a signed octal integer.
o prints an hword_t value as an unsigned octal integer.
O prints an expr_t value as an unsigned octal integer.
z prints an hword_t value as a signed hexadecimal integer.
Z prints an expr_t value as a signed hexadecimal integer.
x prints an hword_t value as an unsigned hexadecimal integer.
X prints an expr_t value as an unsigned hexadecimal integer.
r prints an hword_t value in the current radix.
R prints an expr_t value in the current radix.
v prints an hword_t value in signed variant of current radix.
V prints an expr_t value in signed variant of current radix.
m prints nothing; hence %<width>m prints <width> spaces.
t prints nothing, but adjusts the width such that it
becomes a tabstop. Thus %24t moves to the next column
that is a multiple of 24, and %8t acts like \t would
if \t were implemented in adb.
? converts an integer value, then applies a second
conversion-specifier. If integer was zero, the
output from the second conversion-specifier is
suppressed. For instance, %?s converts one integer
and one string, and prints the string only if the
integer is nonzero (and the pointer is not evaluated).
Thus `adbprintf("%?s", s!=NULL, s)' prints the string
s if and only if the pointer s is not NULL. `?'
conversions may be nested: ("%??x", a, b, c) prints
c only if both a and b are nonzero.
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