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Diffstat (limited to 'contrib/libio/outfloat.c')
| -rw-r--r-- | contrib/libio/outfloat.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/contrib/libio/outfloat.c b/contrib/libio/outfloat.c new file mode 100644 index 0000000..5cbb6c9 --- /dev/null +++ b/contrib/libio/outfloat.c @@ -0,0 +1,211 @@ +/* +Copyright (C) 1993 Free Software Foundation + +This file is part of the GNU IO Library. This library is free +software; you can redistribute it and/or modify it under the +terms of the GNU General Public License as published by the +Free Software Foundation; either version 2, or (at your option) +any later version. + +This library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this library; see the file COPYING. If not, write to the Free +Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +As a special exception, if you link this library with files +compiled with a GNU compiler to produce an executable, this does not cause +the resulting executable to be covered by the GNU General Public License. +This exception does not however invalidate any other reasons why +the executable file might be covered by the GNU General Public License. */ + +#include "libioP.h" + +#ifdef _IO_USE_DTOA +/* Format floating-point number and print them. + Return number of chars printed, or EOF on error. + + sign_mode == '+' : print "-" or "+" + sign_mode == ' ' : print "-" or " " + sign_mode == '\0' : print "-' or "" +*/ + +int +_IO_outfloat (value, sb, type, width, precision, flags, sign_mode, fill) + double value; + _IO_FILE *sb; + int type; + int width; + int precision; + int flags; + int sign_mode; + int fill; +{ + int count = 0; +#define PUT(x) do {if (_IO_putc(x, sb) < 0) goto error; count++;} while (0) +#define PUTN(p, n) \ + do {int _n=n; count+=_n; if (_IO_sputn(sb, p,_n) != _n) goto error;} while(0) +#define PADN(fill, n) \ + do {int _n = n; count+=_n; if (_IO_padn(sb, fill, _n) != _n) goto error;} while (0) + int pad_kind = flags & (_IO_LEFT|_IO_RIGHT|_IO_INTERNAL); + int skip_zeroes = 0; + int show_dot = (flags & _IO_SHOWPOINT) != 0; + int decpt; + int sign; + int mode; + int exponent_size; + int print_sign; + int trailing_zeroes, useful_digits; + int padding, unpadded_width; + char *p; + char *exponent_start; + register int i; +#define EBUF_SIZE 12 +#define EBUF_END &ebuf[EBUF_SIZE] + char ebuf[EBUF_SIZE]; + char *end; + int exp = 0; + switch (type) + { + case 'f': + mode = 3; + break; + case 'e': + case 'E': + exp = type; + mode = 2; + if (precision != 999) + precision++; /* Add one to include digit before decimal point. */ + break; + case 'g': + case 'G': + exp = type == 'g' ? 'e' : 'E'; + if (precision == 0) precision = 1; + if (!(flags & _IO_SHOWPOINT)) + skip_zeroes = 1; + type = 'g'; + mode = 2; + break; + } + /* Do the actual convension */ + if (precision == 999 && mode != 3) + mode = 0; + p = _IO_dtoa(value, mode, precision, &decpt, &sign, &end); + useful_digits = end-p; + exponent_start = EBUF_END; + if (mode == 0) + precision = useful_digits; + /* Check if we need to emit an exponent. */ + if (mode != 3 && decpt != 9999) + { + i = decpt - 1; + if ((type != 'g' && type != 'F') || i < -4 || i >= precision) + { + /* Print the exponent into ebuf. + We write ebuf in reverse order (right-to-left). */ + char sign; + if (i >= 0) + sign = '+'; + else + sign = '-', i = -i; + /* Note: ANSI requires at least 2 exponent digits. */ + do { + *--exponent_start = (i % 10) + '0'; + i /= 10; + } while (i >= 10); + *--exponent_start = i + '0'; + *--exponent_start = sign; + *--exponent_start = exp; + } + } + exponent_size = EBUF_END - exponent_start; + if (mode == 1) + precision = 1; + /* If we print an exponent, always show just one digit before point. */ + if (exponent_size) + decpt = 1; + if (decpt == 9999) + { /* Infinity or NaN */ + decpt = useful_digits; + precision = 0; + show_dot = 0; + } + + /* dtoa truncates trailing zeroes. Set the variable trailing_zeroes to + the number of 0's we have to add (after the decimal point). */ + if (skip_zeroes) + trailing_zeroes = 0; + else if (type == 'f') + trailing_zeroes = useful_digits <= decpt ? precision + : precision-(useful_digits-decpt); + else if (exponent_size) /* 'e' 'E' or 'g' format using exponential notation*/ + trailing_zeroes = precision - useful_digits; + else /* 'g' format not using exponential notation. */ + trailing_zeroes = useful_digits <= decpt ? precision - decpt + : precision-useful_digits; + if (trailing_zeroes < 0) trailing_zeroes = 0; + + if (trailing_zeroes != 0 || useful_digits > decpt) + show_dot = 1; + if (sign_mode == 0) + print_sign = sign ? '-' : 0; + else if (sign_mode == '+') + print_sign = sign ? '-' : '+'; + else /* if (sign_mode == ' ') */ + print_sign = sign ? '-' : ' '; + + /* Calculate the width (before padding). */ + unpadded_width = + (print_sign != 0) + trailing_zeroes + exponent_size + show_dot + + useful_digits + + (decpt > useful_digits ? decpt - useful_digits + : decpt > 0 ? 0 : 1 - decpt); + + padding = width > unpadded_width ? width - unpadded_width : 0; + if (padding > 0 && pad_kind != _IO_LEFT && pad_kind != _IO_INTERNAL) + PADN(fill, padding); /* Default (right) adjust */ + if (print_sign) + PUT(print_sign); + if (pad_kind == _IO_INTERNAL && padding > 0) + PADN(fill, padding); + if (decpt > 0) + { + if (useful_digits >= decpt) + PUTN(p, decpt); + else + { + PUTN(p, useful_digits); + PADN('0', decpt-useful_digits); + } + if (show_dot) + { + PUT('.'); + /* Print digits after the decimal point. */ + if (useful_digits > decpt) + PUTN(p + decpt, useful_digits-decpt); + } + } + else + { + PUT('0'); + if (show_dot) + { + PUT('.'); + PADN('0', -decpt); + /* Print digits after the decimal point. */ + PUTN(p, useful_digits); + } + } + PADN('0', trailing_zeroes); + if (exponent_size) + PUTN(exponent_start, exponent_size); + if (pad_kind == _IO_LEFT && padding > 0) /* Left adjustment*/ + PADN(fill, padding); + return count; + error: + return EOF; +} +#endif |
