| 0,0 → 1,72 |
|---|
| /* |
| FUNCTION |
| <<atof>>, <<atoff>>---string to double or float |
| |
| INDEX |
| atof |
| INDEX |
| atoff |
| |
| ANSI_SYNOPSIS |
| #include <stdlib.h> |
| double atof(const char *<[s]>); |
| float atoff(const char *<[s]>); |
| |
| TRAD_SYNOPSIS |
| #include <stdlib.h> |
| double atof(<[s]>) |
| char *<[s]>; |
| |
| float atoff(<[s]>) |
| char *<[s]>; |
| |
| DESCRIPTION |
| <<atof>> converts the initial portion of a string to a <<double>>. |
| <<atoff>> converts the initial portion of a string to a <<float>>. |
| |
| The functions parse the character string <[s]>, |
| locating a substring which can be converted to a floating-point |
| value. The substring must match the format: |
| . [+|-]<[digits]>[.][<[digits]>][(e|E)[+|-]<[digits]>] |
| The substring converted is the longest initial |
| fragment of <[s]> that has the expected format, beginning with |
| the first non-whitespace character. The substring |
| is empty if <<str>> is empty, consists entirely |
| of whitespace, or if the first non-whitespace character is |
| something other than <<+>>, <<->>, <<.>>, or a digit. |
| |
| <<atof(<[s]>)>> is implemented as <<strtod(<[s]>, NULL)>>. |
| <<atoff(<[s]>)>> is implemented as <<strtof(<[s]>, NULL)>>. |
| |
| RETURNS |
| <<atof>> returns the converted substring value, if any, as a |
| <<double>>; or <<0.0>>, if no conversion could be performed. |
| If the correct value is out of the range of representable values, plus |
| or minus <<HUGE_VAL>> is returned, and <<ERANGE>> is stored in |
| <<errno>>. |
| If the correct value would cause underflow, <<0.0>> is returned |
| and <<ERANGE>> is stored in <<errno>>. |
| |
| <<atoff>> obeys the same rules as <<atof>>, except that it |
| returns a <<float>>. |
| |
| PORTABILITY |
| <<atof>> is ANSI C. <<atof>>, <<atoi>>, and <<atol>> are subsumed by <<strod>> |
| and <<strol>>, but are used extensively in existing code. These functions are |
| less reliable, but may be faster if the argument is verified to be in a valid |
| range. |
| |
| Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>, |
| <<lseek>>, <<read>>, <<sbrk>>, <<write>>. |
| */ |
| |
| |
| #include <stdlib.h> |
| #include <_ansi.h> |
| |
| double |
| _DEFUN (atof, (s), |
| _CONST char *s) |
| { |
| return strtod (s, NULL); |
| } |