projects / thirdparty / util-linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 670b10ae KZ |
1 | /* |
| 2 | * Locale-independent strtod(). | |
| 3 | * | |
| 4 | * This file may be redistributed under the terms of the | |
| 5 | * GNU Lesser General Public License. | |
| 6 | * | |
| 7 | * Copyright (C) 2021 Karel Zak <kzak@redhat.com> | |
| 8 | */ | |
| 9 | #include "c.h" | |
| 10 | ||
| 11 | #include <locale.h> | |
| 12 | #include <stdlib.h> | |
| 13 | #include <string.h> | |
| 14 | ||
| 15 | #include "c_strtod.h" | |
| 16 | ||
| dc6a38ed KZ |
17 | #ifdef __APPLE__ |
| 18 | # include <xlocale.h> | |
| 19 | #endif | |
| 20 | ||
| 670b10ae KZ |
21 | #if defined(HAVE_NEWLOCALE) && (defined(HAVE_STRTOD_L) || defined(HAVE_USELOCALE)) |
| 22 | # define USE_CLOCALE | |
| 23 | #endif | |
| 24 | ||
| 25 | #if defined(USE_CLOCALE) | |
| 26 | static volatile locale_t c_locale; | |
| 27 | ||
| 28 | static locale_t get_c_locale(void) | |
| 29 | { | |
| 30 | if (!c_locale) | |
| 31 | c_locale = newlocale(LC_ALL_MASK, "C", (locale_t) 0); | |
| 32 | return c_locale; | |
| 33 | } | |
| 34 | #endif | |
| 35 | ||
| 36 | ||
| 37 | double c_strtod(char const *str, char **end) | |
| 38 | { | |
| 39 | double res; | |
| 40 | int errsv; | |
| 41 | ||
| 42 | #if defined(USE_CLOCALE) | |
| 43 | locale_t cl = get_c_locale(); | |
| 44 | ||
| 45 | #if defined(HAVE_STRTOD_L) | |
| 46 | /* | |
| 47 | * A) try strtod_l() for "C" locale | |
| 48 | */ | |
| 49 | if (cl) | |
| 50 | return strtod_l(str, end, cl); | |
| 51 | #elif defined(HAVE_USELOCALE) | |
| 52 | /* | |
| aa3cab8e | 53 | * B) classic strtod(), but switch to "C" locale by uselocale() |
| 670b10ae KZ |
54 | */ |
| 55 | if (cl) { | |
| aa3cab8e | 56 | locale_t org_cl = uselocale(cl); |
| 670b10ae KZ |
57 | if (!org_cl) |
| 58 | return 0; | |
| 59 | ||
| 60 | res = strtod(str, end); | |
| 61 | errsv = errno; | |
| 62 | ||
| 63 | uselocale(org_cl); | |
| 64 | errno = errsv; | |
| 65 | return res; | |
| 66 | } | |
| 67 | #endif /* HAVE_USELOCALE */ | |
| 68 | #endif /* USE_CLOCALE */ | |
| 69 | /* | |
| 70 | * C) classic strtod(), but switch to "C" locale by setlocale() | |
| 71 | */ | |
| 72 | char *org_locale = setlocale(LC_NUMERIC, NULL); | |
| 73 | ||
| 74 | if (org_locale) { | |
| 75 | org_locale = strdup(org_locale); | |
| 76 | if (!org_locale) | |
| 77 | return 0; | |
| 78 | ||
| 79 | setlocale(LC_NUMERIC, "C"); | |
| 80 | } | |
| 81 | res = strtod(str, end); | |
| 82 | errsv = errno; | |
| 83 | ||
| 84 | if (org_locale) { | |
| 85 | setlocale(LC_NUMERIC, org_locale); | |
| 86 | free(org_locale); | |
| 87 | } | |
| 88 | errno = errsv; | |
| 89 | return res; | |
| 90 | } | |
| 91 | ||
| 92 | #ifdef TEST_PROGRAM | |
| 93 | int main(int argc, char *argv[]) | |
| 94 | { | |
| 95 | double res; | |
| 96 | char *end; | |
| 97 | ||
| 98 | if (argc < 2) { | |
| 99 | fprintf(stderr, "usage: %s decimal.number\n", | |
| 100 | program_invocation_short_name); | |
| 101 | return EXIT_FAILURE; | |
| 102 | } | |
| 103 | ||
| 104 | res = c_strtod(argv[1], &end); | |
| 105 | printf("Result: %g, errno: %d, endptr: '%s'\n", res, errno, end); | |
| 106 | ||
| 107 | return errno ? EXIT_FAILURE : EXIT_SUCCESS; | |
| 108 | } | |
| 109 | #endif |