Subversion Repositories openrisc_2011-10-31

/*

FUNCTION

<<ecvt>>, <<ecvtf>>, <<fcvt>>, <<fcvtf>>---double or float to string

INDEX

        ecvt

INDEX

        ecvtf

INDEX

        fcvt

INDEX

        fcvtf

ANSI_SYNOPSIS

        #include <stdlib.h>

        char *ecvt(double <[val]>, int <[chars]>, int *<[decpt]>, int *<[sgn]>);

        char *ecvtf(float <[val]>, int <[chars]>, int *<[decpt]>, int *<[sgn]>);

        char *fcvt(double <[val]>, int <[decimals]>,

                   int *<[decpt]>, int *<[sgn]>);

        char *fcvtf(float <[val]>, int <[decimals]>,

                    int *<[decpt]>, int *<[sgn]>);

TRAD_SYNOPSIS

        #include <stdlib.h>

        char *ecvt(<[val]>, <[chars]>, <[decpt]>, <[sgn]>);

        double <[val]>;

        int <[chars]>;

        int *<[decpt]>;

        int *<[sgn]>;

        char *ecvtf(<[val]>, <[chars]>, <[decpt]>, <[sgn]>);

        float <[val]>;

        int <[chars]>;

        int *<[decpt]>;

        int *<[sgn]>;

        char *fcvt(<[val]>, <[decimals]>, <[decpt]>, <[sgn]>);

        double <[val]>;

        int <[decimals]>;

        int *<[decpt]>;

        int *<[sgn]>;

        char *fcvtf(<[val]>, <[decimals]>, <[decpt]>, <[sgn]>);

        float <[val]>;

        int <[decimals]>;

        int *<[decpt]>;

        int *<[sgn]>;

DESCRIPTION

<<ecvt>> and <<fcvt>> produce (null-terminated) strings of digits

representating the <<double>> number <[val]>.

<<ecvtf>> and <<fcvtf>> produce the corresponding character

representations of <<float>> numbers.

(The <<stdlib>> functions <<ecvtbuf>> and <<fcvtbuf>> are reentrant

versions of <<ecvt>> and <<fcvt>>.)

The only difference between <<ecvt>> and <<fcvt>> is the

interpretation of the second argument (<[chars]> or <[decimals]>).

For <<ecvt>>, the second argument <[chars]> specifies the total number

of characters to write (which is also the number of significant digits

in the formatted string, since these two functions write only digits).

For <<fcvt>>, the second argument <[decimals]> specifies the number of

characters to write after the decimal point; all digits for the integer

part of <[val]> are always included.

Since <<ecvt>> and <<fcvt>> write only digits in the output string,

they record the location of the decimal point in <<*<[decpt]>>>, and

the sign of the number in <<*<[sgn]>>>.  After formatting a number,

<<*<[decpt]>>> contains the number of digits to the left of the

decimal point.  <<*<[sgn]>>> contains <<0>> if the number is positive,

and <<1>> if it is negative.

RETURNS

All four functions return a pointer to the new string containing a

character representation of <[val]>.

PORTABILITY

None of these functions are ANSI C.

Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,

<<lseek>>, <<read>>, <<sbrk>>, <<write>>.

NEWPAGE

FUNCTION

<<gvcvt>>, <<gcvtf>>---format double or float as string

INDEX

        gcvt

INDEX

        gcvtf

ANSI_SYNOPSIS

        #include <stdlib.h>

        char *gcvt(double <[val]>, int <[precision]>, char *<[buf]>);

        char *gcvtf(float <[val]>, int <[precision]>, char *<[buf]>);

TRAD_SYNOPSIS

        #include <stdlib.h>

        char *gcvt(<[val]>, <[precision]>, <[buf]>);

        double <[val]>;

        int <[precision]>;

        char *<[buf]>;

        char *gcvtf(<[val]>, <[precision]>, <[buf]>);

        float <[val]>;

        int <[precision]>;

        char *<[buf]>;

DESCRIPTION

<<gcvt>> writes a fully formatted number as a null-terminated

string in the buffer <<*<[buf]>>>.  <<gdvtf>> produces corresponding

character representations of <<float>> numbers.

<<gcvt>> uses the same rules as the <<printf>> format

`<<%.<[precision]>g>>'---only negative values are signed (with

`<<->>'), and either exponential or ordinary decimal-fraction format

is chosen depending on the number of significant digits (specified by

<[precision]>).

RETURNS

The result is a pointer to the formatted representation of <[val]>

(the same as the argument <[buf]>).

PORTABILITY

Neither function is ANSI C.

Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,

<<lseek>>, <<read>>, <<sbrk>>, <<write>>.

*/

#include <_ansi.h>

#include <reent.h>

#include <stdio.h>

#include <stdlib.h>

#include "local.h"

char *

_DEFUN (fcvt, (d, ndigit, decpt, sign),

        double d _AND

        int ndigit _AND

        int *decpt _AND

        int *sign)

{

  return fcvtbuf (d, ndigit, decpt, sign, NULL);

}

char *

_DEFUN (fcvtf, (d, ndigit, decpt, sign),

        float d _AND

        int ndigit _AND

        int *decpt _AND

        int *sign)

{

  return fcvt ((float) d, ndigit, decpt, sign);

}

char *

_DEFUN (gcvtf, (d, ndigit, buf),

        float d _AND

        int ndigit _AND

        char *buf)

{

  double asd = d;

  return gcvt (asd, ndigit, buf);

}

char *

_DEFUN (ecvt, (d, ndigit, decpt, sign),

        double d _AND

        int ndigit _AND

        int *decpt _AND

        int *sign)

{

  return ecvtbuf (d, ndigit, decpt, sign, NULL);

}

char *

_DEFUN (ecvtf, (d, ndigit, decpt, sign),

        float d _AND

        int ndigit _AND

        int *decpt _AND

        int *sign)

{

  return ecvt ((double) d, ndigit, decpt, sign);

}

char *

_DEFUN (gcvt, (d, ndigit, buf),

        double d _AND

        int ndigit _AND

        char *buf)

{

  char *tbuf = buf;

  if (d < 0) {

    *buf = '-';

    buf++;

    ndigit--;

  }

  return (_gcvt (_REENT, d, ndigit, buf, 'g', 0) ? tbuf : 0);

}