Strtod, strtof, Synopsis, Returns – Zilog ZUSBOPTS User Manual

Page 477: Example

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UM017105-0511

Standard Functions

Zilog Developer Studio II – ZNEO™

User Manual

449

Synopsis

#include <string.h>

char *strstr(const char *s1, const char *s2);

Returns

A pointer to the located string or a null pointer if the string is not found.

Example

char *ptr;

char s1[]="Production Languages";

char s2[]="Lang";

ptr=strstr(s1,s2);

strtod, strtof

Converts the string pointed to by nptr to

double

(

strtod

) or

float

(

strtof

) represen-

tation. The function recognizes an optional leading sequence of white-space characters (as
specified by the

isspace

function), then an optional plus or minus sign, then a sequence

of digits optionally containing a decimal point, then an optional letter e or E followed by
an optionally signed integer, then an optional floating suffix. If an inappropriate character
occurs before the first digit following the e or E, the exponent is taken to be zero.

The first inappropriate character ends the conversion. If endptr is not a null pointer, a
pointer to that character is stored in the object endptr points to; if an inappropriate charac-
ter occurs before any digit, the value of nptr is stored.

The sequence of characters from the first digit or the decimal point (whichever occurs
first) to the character before the first inappropriate character is interpreted as a floating
constant according to the rules of this section, except that if neither an exponent part or a
decimal point appears, a decimal point is assumed to follow the last digit in the string. If a
minus sign appears immediately before the first digit, the value resulting from the conver-
sion is negated.

Synopsis

#include <stdlib.h>

double strtod(const char *nptr, char **endptr);

float strtof(const char *nptr, char **endptr);

Returns

The converted value, or zero if an inappropriate character occurs before any digit. If the
correct value would cause overflow, plus or minus HUGE_VAL is returned (according to
the sign of the value), and the macro

errno

acquires the value ERANGE. If the correct

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