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(): _SVID_SOURCE || _XOPEN_SOURCE >= 500

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().

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 preferable).

NOTES
       Linux libc4 and libc5 specified the type of ndigits as size_t.  Not all locales use a point as the radix character ("dec-
       imal point").

SEE ALSO
       ecvt_r(3), gcvt(3), qecvt(3), setlocale(3), sprintf(3)

COLOPHON
       This  page  is  part of release 3.25 of the Linux man-pages project.  A description of the project, and information about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



                                                           2009-03-15                                                    ECVT(3)