Standard C Library Functions                             ecvt(3C)



NAME
     ecvt, fcvt, gcvt - convert floating-point number to string

SYNOPSIS
     #include 

     char *ecvt(double value, int ndigit, int *restrict decpt, int *restrict sign);


     char *fcvt(double value, int ndigit, int *restrict decpt, int *restrict sign);


     char *gcvt(double value, int ndigit, char *buf);


DESCRIPTION
     The ecvt(), fcvt() and gcvt()  functions  convert  floating-
     point numbers to null-terminated strings.

  ecvt()
     The ecvt() function  converts  value  to  a  null-terminated
     string  of  ndigit  digits  (where  ndigit  is reduced to an
     unspecified limit determined by the precision of  a  double)
     and  returns  a pointer to the string.  The high-order digit
     is non-zero, unless the value is 0.  The low-order digit  is
     rounded.   The  position  of the radix character relative to
     the beginning of the string is stored in the integer pointed
     to  by  decpt  (negative  means  to the left of the returned
     digits). The radix character is not included in the returned
     string.  If  the sign of the result is negative, the integer
     pointed to by sign is non-zero, otherwise it is 0.


     If the converted value is out of range or is not  represent-
     able, the contents of the returned string are unspecified.

  fcvt()
     The fcvt() function is identical to ecvt() except that  ndi-
     git  specifies  the number of digits desired after the radix
     point.  The total number of digits in the result  string  is
     restricted to an unspecified limit as determined by the pre-
     cision of a double.

  gcvt()
     The gcvt() function  converts  value  to  a  null-terminated
     string  (similar  to that of the %g format of printf(3C)) in
     the array pointed to by buf and  returns  buf.  It  produces
     ndigit  significant  digits (limited to an unspecified value
     determined by the precision of a double) in %f if  possible,
     or  %e  (scientific  notation)  otherwise.   A minus sign is
     included in the returned string if value is less than 0.   A
     radix  character is included in the returned string if value



SunOS 5.11          Last change: 18 May 2004                    1






Standard C Library Functions                             ecvt(3C)



     is not a whole number.  Trailing zeros are suppressed  where
     value  is not a whole number.  The radix character is deter-
     mined by the current locale. If setlocale(3C) has  not  been
     called  successfully,  the  default  locale, POSIX, is used.
     The default locale specifies a period (.) as the radix char-
     acter.   The LCNUMERIC category determines the value of the
     radix character within the current locale.

RETURN VALUES
     The ecvt() and fcvt() functions return a pointer to a  null-
     terminated string of digits.


     The gcvt() function returns buf.

ERORS
     No errors are defined.

USAGE
     The return values from ecvt()  and  fcvt()  might  point  to
     thread-specific  data  that can be overwritten by subsequent
     calls to these functions by the same thread.


     For portability to  implementations  conforming  to  earlier
     versions  of  Solaris,  sprintf(3C)  is  preferred over this
     function.

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Standard                    
    
     MT-Level                     Safe                        
    


SEE ALSO
     printf(3C), setlocale(3C), sprintf(3C), attributes(5), stan-
     dards(5)









SunOS 5.11          Last change: 18 May 2004                    2