1 /* Convert string to double, using the C locale. -*- coding: utf-8 -*- 2 3 Copyright (C) 2003-2004, 2009-2021 Free Software Foundation, Inc. 4 5 This program is free software: you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by 7 the Free Software Foundation; either version 3 of the License, or 8 (at your option) any later version. 9 10 This program is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 GNU General Public License for more details. 14 15 You should have received a copy of the GNU General Public License 16 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 17 18 #ifdef __cplusplus 19 extern "C" { 20 #endif 21 22 /* Parse the initial portion of the string pointed to by NPTR as a floating- 23 point number (in decimal or hexadecimal notation), like in the C locale: 24 accepting only the ASCII digits '0'..'9', and only '.' as decimal point 25 character. 26 If ENDPTR is not NULL, set *ENDPTR to point to the first byte beyond the 27 parsed number or to NPTR if the string does not start with a parsable 28 number. 29 Return value: 30 - If successful, return the value as a double or 'long double', 31 respectively, and don't modify errno. 32 - In case of overflow, return ±HUGE_VAL or ±HUGE_VALL, respectively, and 33 set errno to ERANGE. 34 - In case of underflow, return a value very near to 0 and set errno to 35 ERANGE. 36 - If the string does not start with a number at all, return 0 (and recall 37 that if ENDPTR != NULL, *ENDPTR is set to NPTR), and maybe set errno to 38 EINVAL. 39 - In case of other error, return 0 and set errno, for example to ENOMEM. */ 40 extern double c_strtod (char const *nptr, char **endptr); 41 extern long double c_strtold (char const *nptr, char **endptr); 42 43 #ifdef __cplusplus 44 } 45 #endif