Date: Tue, 21 Feb 95 10:27:34 +0100
From: pascal DOT richard AT art DOT alcatel DOT fr (Pascal RICHARD)
To: HERZER AT rz-nov2 DOT rz DOT FH-Weingarten DOT DE
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: float to string

> 
> Hello everybody,
> 
> is there a function that converts a float into a string (like 
> ecvt, fcvt, and gcvt in TURBO C). I am converting "by hand" and want 
> to know if there are some changes to the compiler now (wasn't there 
> an e-,f-,gcvt entry in the info reader for GNU C 2.5.8? When I look 
> into the new Info reader (that comes with GCC 2.6.x) I miss these 
> entries [and I remember that I tried to use these functions with 
> 2.5.8 without any success -> undefined references errors]).
> 
> BTW: The TURBO C manual claims these funcions as "available on UNIX-
> Systems".
> 
> Can anybody help?
> 
> Thanks in advance,
> 
> Armin
> 
Hi,
   I try a "man ecvt" on my UNIX station and it says that [efg]cvt are
obsolet ans that you should use [efg]convert instead.

 On my station the declaration in include files are only : "char
*econvert()", it's minimalist so I send the man output too as I can't
check the DOS version at work.

------- man econvert ---------

NAME
     econvert, fconvert, gconvert, seconvert,  sfconvert,  sgcon-
     vert, ecvt, fcvt, gcvt - output conversion

SYNOPSIS
     #include <floatingpoint.h>

     char *econvert(value, ndigit, decpt, sign, buf)
     double value;
     int ndigit, *decpt, *sign;
     char *buf;

     char *fconvert(value, ndigit, decpt, sign, buf)
     double value;
     int ndigit, *decpt, *sign;
     char *buf;

     char *gconvert(value, ndigit, trailing, buf)
     double value;
     int ndigit;
     int trailing;
     char *buf;

     char *seconvert(value, ndigit, decpt, sign, buf)
     single *value;
     int ndigit, *decpt, *sign;
     char *buf;

     char *sfconvert(value, ndigit, decpt, sign, buf)
     single *value;
     int ndigit, *decpt, *sign;
     char *buf;

     char *sgconvert(value, ndigit, trailing, buf)
     single *value;
     int ndigit;
     int trailing;
     char *buf;

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

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

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

DESCRIPTION
     econvert() converts the value to a null-terminated string of
     ndigit  ASCII  digits  in  buf and returns a pointer to buf.
     buf should contain at least ndigit+1 characters.  The  posi-
     tion of the radix character relative to the beginning of the
     string is stored indirectly  through  decpt.   Thus  buf  ==
     "314"  and  *decpt  ==  1 corresponds to the numerical value
     3.14, while buf == "314" and *decpt == -1 corresponds to the
     numerical  value  .0314.  If the sign of the result is nega-
     tive, the word pointed to by sign is nonzero;  otherwise  it
     is zero.  The least significant digit is rounded.

     fconvert works much like econvert, except that  the  correct
     digit  has been rounded as if for sprintf(%w.nf) output with
     n=ndigit digits to the right of the radix character.  ndigit
     can  be  negative  to  indicate  rounding to the left of the
     radix character.  The return value is a pointer to buf.  buf
     should  contain  at  least  310+max(0,ndigit)  characters to
     accomodate any double-precision value.

     gconvert() converts the value  to  a  null-terminated  ASCII
     string  in  buf  and  returns a pointer to buf.  It produces
     ndigit significant  digits  in  fixed-decimal  format,  like
     sprintf(%w.nf),  if  possible,  and  otherwise  in floating-
     decimal format, like sprintf(%w.ne); in either case  buf  is
     ready  for  printing,  with  sign  and exponent.  The result
     corresponds to that obtained by

          (void) sprintf(buf, "%w.ng", value);

     If trailing= 0, trailing zeros  and  a  trailing  point  are
     suppressed,  as  in  sprintf(%g).  If trailing!= 0, trailing
     zeros and a trailing point are retained, as in sprintf(%#g).

     seconvert, sfconvert, and sgconvert()  are  single-precision
     versions of these functions, and are more efficient than the
     corresponding double-precision versions.  A  pointer  rather
     than  the  value itself is passed to avoid C's usual conver-
     sion of single-precision arguments to double.

     ecvt() and fcvt() are obsolete versions  of  econvert()  and
     fconvert()  that  create  a  string  in  a static data area,
     overwritten by each call, and return values  that  point  to
     that  static  data.  These functions are therefore not reen-
     trant.

     gcvt() is an obsolete  version  of  gconvert()  that  always
     suppresses trailing zeros and point.

     IEEE Infinities and NaNs  are  treated  similarly  by  these
     functions.   ``NaN''  is  returned  for  NaN, and ``Inf'' or
     ``Infinity'' for Infinity.  The longer form is produced when

     ndigit >= 8.

     The radix character is determined by the current setting  of
     the  program's  locale  (category  LC_NUMERIC).   In the "C"
     locale or if the locale is undefined, the  readix  character
     defaults to a period `.'.

SEE ALSO
     printf(3V)