| ecvt(3) - phpMan
ECVT(3) Linux Programmer's Manual ECVT(3)
NAME
ecvt, fcvt - convert a floating-point number to a string
SYNOPSIS
#include <stdlib.h>
char *ecvt(double number, int ndigits, int *decpt, int *sign);
char *fcvt(double number, int ndigits, int *decpt, int *sign);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
ecvt(), fcvt():
Since glibc 2.12:
_SVID_SOURCE ||
(_XOPEN_SOURCE >= 500 ||
_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) &&
!(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600)
Before glibc 2.12:
_SVID_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
DESCRIPTION
The ecvt() function converts number to a null-terminated string of ndigits digits (where
ndigits is reduced to a system-specific limit determined by the precision of a double),
and returns a pointer to the string. The high-order digit is nonzero, unless number is
zero. The low order digit is rounded. The string itself does not contain a decimal
point; however, the position of the decimal point relative to the start of the string is
stored in *decpt. A negative value for *decpt means that the decimal point is to the left
of the start of the string. If the sign of number is negative, *sign is set to a nonzero
value, otherwise it is set to 0. If number is zero, it is unspecified whether *decpt is 0
or 1.
The fcvt() function is identical to ecvt(), except that ndigits specifies the number of
digits after the decimal point.
RETURN VALUE
Both the ecvt() and fcvt() functions return a pointer to a static string containing the
ASCII representation of number. The static string is overwritten by each call to ecvt()
or fcvt().
ATTRIBUTES
Multithreading (see pthreads(7))
The ecvt() and fcvt() functions are not thread-safe.
CONFORMING TO
SVr2; marked as LEGACY in POSIX.1-2001. POSIX.1-2008 removes the specifications of ecvt()
and fcvt(), recommending the use of sprintf(3) instead (though snprintf(3) may be preferā
able).
NOTES
Not all locales use a point as the radix character ("decimal point").
SEE ALSO
ecvt_r(3), gcvt(3), qecvt(3), setlocale(3), sprintf(3)
COLOPHON
This page is part of release 3.74 of the Linux man-pages project. A description of the
project, information about reporting bugs, and the latest version of this page, can be
found at http://www.kernel.org/doc/man-pages/.
2014-08-19 ECVT(3)
|