Analog Devices VISUALDSP++ 3.5 Manual page 289

A hexadecimal floating-point number may start with an optional plus ( + )
or minus ( - ) followed by the hexadecimal prefix
sequence must be followed by one or more hexadecimal characters that
optionally contain a decimal point ( . ).
The hexadecimal digits are followed by a binary exponent that consists of
the letter or
p P
digits. The exponent is interpreted as a power of two that is used to scale
the fraction represented by the tokens
The first character that does not fit either form of number will stop the
scan.
Error Conditions
The function returns a zero if no conversion could be made. If the
atof
correct value results in an overflow, a positive or negative (as appropriate)
is returned. If the correct value results in an underflow, 0.0 is
HUGE_VAL
returned. The
flow or underflow.
Notes
The function reference
strtod (pdata, (char *) NULL);
and therefore, if the function returns zero, it is not possible to determine
whether the character string contained a (valid) representation of 0.0 or
some invalid numerical string.
Example
#include <stdlib.h>
double x;
x = atof("5.5");
VisualDSP++ 3.5 C/C++ Compiler and Library Manual
for ADSP-219x DSPs
, an optional sign, and a non-empty sequence of decimal
value is stored in
ERANGE
atof (pdata)
/* x == 5.5 */
C/C++ Run-Time Library
or
0x 0X
[hexdigs] [.hexdigs]
in the case of either an over-
errno
is functionally equivalent to:
. This character
.
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