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author | David Hildenbrand <david@redhat.com> | 2018-11-21 17:44:13 +0100 |
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committer | Markus Armbruster <armbru@redhat.com> | 2018-12-13 19:10:06 +0100 |
commit | ca28f5481607e5c59481e70e429f5dd23662cb69 (patch) | |
tree | 370334e609a4101c59241337f4ba87a1fcb4c3a9 /util | |
parent | c3ec0fa1a8e815ecfec9eabb9c20ee206c313e07 (diff) | |
download | qemu-ca28f5481607e5c59481e70e429f5dd23662cb69.zip qemu-ca28f5481607e5c59481e70e429f5dd23662cb69.tar.gz qemu-ca28f5481607e5c59481e70e429f5dd23662cb69.tar.bz2 |
cutils: Add qemu_strtod() and qemu_strtod_finite()
Let's provide a wrapper for strtod().
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20181121164421.20780-2-david@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Diffstat (limited to 'util')
-rw-r--r-- | util/cutils.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/util/cutils.c b/util/cutils.c index 0621565..ec0a401 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -552,6 +552,71 @@ int qemu_strtou64(const char *nptr, const char **endptr, int base, } /** + * Convert string @nptr to a double. + * + * This is a wrapper around strtod() that is harder to misuse. + * Semantics of @nptr and @endptr match strtod() with differences + * noted below. + * + * @nptr may be null, and no conversion is performed then. + * + * If no conversion is performed, store @nptr in *@endptr and return + * -EINVAL. + * + * If @endptr is null, and the string isn't fully converted, return + * -EINVAL. This is the case when the pointer that would be stored in + * a non-null @endptr points to a character other than '\0'. + * + * If the conversion overflows, store +/-HUGE_VAL in @result, depending + * on the sign, and return -ERANGE. + * + * If the conversion underflows, store +/-0.0 in @result, depending on the + * sign, and return -ERANGE. + * + * Else store the converted value in @result, and return zero. + */ +int qemu_strtod(const char *nptr, const char **endptr, double *result) +{ + char *ep; + + if (!nptr) { + if (endptr) { + *endptr = nptr; + } + return -EINVAL; + } + + errno = 0; + *result = strtod(nptr, &ep); + return check_strtox_error(nptr, ep, endptr, errno); +} + +/** + * Convert string @nptr to a finite double. + * + * Works like qemu_strtod(), except that "NaN" and "inf" are rejected + * with -EINVAL and no conversion is performed. + */ +int qemu_strtod_finite(const char *nptr, const char **endptr, double *result) +{ + double tmp; + int ret; + + ret = qemu_strtod(nptr, endptr, &tmp); + if (!ret && !isfinite(tmp)) { + if (endptr) { + *endptr = nptr; + } + ret = -EINVAL; + } + + if (ret != -EINVAL) { + *result = tmp; + } + return ret; +} + +/** * Searches for the first occurrence of 'c' in 's', and returns a pointer * to the trailing null byte if none was found. */ |