From: Frank Stettner Date: Fri, 26 Jan 2018 12:53:45 +0000 (+0100) Subject: strutil: Locale independent snprintf() and vsnprintf() functions X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=79034d4f39f76415e463f02d6b60f5269481da9f;p=libsigrok.git strutil: Locale independent snprintf() and vsnprintf() functions --- diff --git a/bindings/cxx/classes.cpp b/bindings/cxx/classes.cpp index a0b161a6..d25c53cf 100644 --- a/bindings/cxx/classes.cpp +++ b/bindings/cxx/classes.cpp @@ -18,8 +18,9 @@ */ /* Needed for isascii(), as used in the GNU libstdc++ headers */ +/* Needed in strutil.c for POSIX.1-2008 locale functions */ #ifndef _XOPEN_SOURCE -#define _XOPEN_SOURCE 600 +#define _XOPEN_SOURCE 700 #endif #include diff --git a/include/libsigrok/proto.h b/include/libsigrok/proto.h index 7f312937..08e12496 100644 --- a/include/libsigrok/proto.h +++ b/include/libsigrok/proto.h @@ -245,6 +245,10 @@ SR_API uint64_t sr_parse_timestring(const char *timestring); SR_API gboolean sr_parse_boolstring(const char *boolstring); SR_API int sr_parse_period(const char *periodstr, uint64_t *p, uint64_t *q); SR_API int sr_parse_voltage(const char *voltstr, uint64_t *p, uint64_t *q); +SR_API int sr_snprintf_ascii(char *buf, size_t buf_size, + const char *format, ...); +SR_API int sr_vsnprintf_ascii(char *buf, size_t buf_size, + const char *format, va_list args); SR_API int sr_parse_rational(const char *str, struct sr_rational *ret); /*--- version.c -------------------------------------------------------------*/ diff --git a/src/strutil.c b/src/strutil.c index 5344ec29..e58537b3 100644 --- a/src/strutil.c +++ b/src/strutil.c @@ -17,8 +17,17 @@ * along with this program; if not, see . */ +/* Needed for POSIX.1-2008 locale functions */ +#define _XOPEN_SOURCE 700 #include #include +#include +#if defined(__FreeBSD__) || defined(__APPLE__) +#include +#endif +#if defined(__FreeBSD__) +#include +#endif #include #include #include @@ -250,6 +259,178 @@ SR_PRIV int sr_atof_ascii(const char *str, float *ret) return SR_OK; } +/** + * Composes a string with a format string (like printf) in the buffer pointed + * by buf (taking buf_size as the maximum buffer capacity to fill). + * If the resulting string would be longer than n - 1 characters, the remaining + * characters are discarded and not stored, but counted for the value returned + * by the function. + * A terminating NUL character is automatically appended after the content + * written. + * After the format parameter, the function expects at least as many additional + * arguments as needed for format. + * + * This version ignores the actual locale and uses the locale "C" for Linux, + * FreeBSD, OSX and Android. + * + * @param buf Pointer to a buffer where the resulting C string is stored. + * @param buf_size Maximum number of bytes to be used in the buffer. The + * generated string has a length of at most buf_size - 1, leaving space + * for the additional terminating NUL character. + * @param format C string that contains a format string (see printf). + * @param ... A sequence of additional arguments, each containing a value to be + * used to replace a format specifier in the format string. + * + * @return On success, the number of characters that would have been written if + * buf_size had been sufficiently large, not counting the terminating + * NUL character. On failure, a negative number is returned. + * Notice that only when this returned value is non-negative and less + * than buf_size, the string has been completely written. + * + * @since 0.6.0 + */ +SR_API int sr_snprintf_ascii(char *buf, size_t buf_size, + const char *format, ...) +{ + int ret; + va_list args; + + va_start(args, format); + ret = sr_vsnprintf_ascii(buf, buf_size, format, args); + va_end(args); + + return ret; +} + +/** + * Composes a string with a format string (like printf) in the buffer pointed + * by buf (taking buf_size as the maximum buffer capacity to fill). + * If the resulting string would be longer than n - 1 characters, the remaining + * characters are discarded and not stored, but counted for the value returned + * by the function. + * A terminating NUL character is automatically appended after the content + * written. + * Internally, the function retrieves arguments from the list identified by + * args as if va_arg was used on it, and thus the state of args is likely to + * be altered by the call. + * In any case, arg should have been initialized by va_start at some point + * before the call, and it is expected to be released by va_end at some point + * after the call. + * + * This version ignores the actual locale and uses the locale "C" for Linux, + * FreeBSD, OSX and Android. + * + * @param buf Pointer to a buffer where the resulting C string is stored. + * @param buf_size Maximum number of bytes to be used in the buffer. The + * generated string has a length of at most buf_size - 1, leaving space + * for the additional terminating NUL character. + * @param format C string that contains a format string (see printf). + * @param args A value identifying a variable arguments list initialized with + * va_start. + * + * @return On success, the number of characters that would have been written if + * buf_size had been sufficiently large, not counting the terminating + * NUL character. On failure, a negative number is returned. + * Notice that only when this returned value is non-negative and less + * than buf_size, the string has been completely written. + * + * @since 0.6.0 + */ +SR_API int sr_vsnprintf_ascii(char *buf, size_t buf_size, + const char *format, va_list args) +{ +#if defined(_WIN32) + int ret; + +#if 0 + /* + * TODO: This part compiles with mingw-w64 but doesn't run with Win7. + * Doesn't start because of "Procedure entry point _create_locale + * not found in msvcrt.dll". + * mingw-w64 should link to msvcr100.dll not msvcrt.dll!. + */ + _locale_t locale; + + locale = _create_locale(LC_NUMERIC, "C"); + ret = _vsnprintf_l(buf, buf_size, format, locale, args); + _free_locale(locale); +#endif + + /* vsprintf uses the current locale, may cause issues for floats. */ + ret = vsnprintf(buf, buf_size, format, args); + + return ret; +#elif defined(__APPLE__) + /* + * See: + * https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man3/printf_l.3.html + * https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man3/xlocale.3.html + */ + int ret; + locale_t locale; + + locale = newlocale(LC_NUMERIC_MASK, "C", NULL); + ret = vsnprintf_l(buf, buf_size, locale, format, args); + freelocale(locale); + + return ret; +#elif defined(__FreeBSD__) && __FreeBSD_version >= 901000 + /* + * See: + * https://www.freebsd.org/cgi/man.cgi?query=printf_l&apropos=0&sektion=3&manpath=FreeBSD+9.1-RELEASE + * https://www.freebsd.org/cgi/man.cgi?query=xlocale&apropos=0&sektion=3&manpath=FreeBSD+9.1-RELEASE + */ + int ret; + locale_t locale; + + locale = newlocale(LC_NUMERIC_MASK, "C", NULL); + ret = vsnprintf_l(buf, buf_size, locale, format, args); + freelocale(locale); + + return ret; +#elif defined(__ANDROID__) + /* + * The Bionic libc only has two locales ("C" aka "POSIX" and "C.UTF-8" + * aka "en_US.UTF-8"). The decimal point is hard coded as ".". + * See: https://android.googlesource.com/platform/bionic/+/master/libc/bionic/locale.cpp + */ + int ret; + + ret = vsnprintf(buf, buf_size, format, args); + + return ret; +#elif defined(__linux__) + int ret; + locale_t old_locale, temp_locale; + + /* Switch to C locale for proper float/double conversion. */ + temp_locale = newlocale(LC_NUMERIC, "C", NULL); + old_locale = uselocale(temp_locale); + + ret = vsnprintf(buf, buf_size, format, args); + + /* Switch back to original locale. */ + uselocale(old_locale); + freelocale(temp_locale); + + return ret; +#elif defined(__unix__) || defined(__unix) + /* + * This is a fallback for all other BSDs, *nix and FreeBSD <= 9.0, by + * using the current locale for snprintf(). This may not work correctly + * for floats! + */ + int ret; + + ret = vsnprintf(buf, buf_size, format, args); + + return ret; +#else + /* No implementation for unknown systems! */ + return -1; +#endif +} + /** * Convert a string representation of a numeric value to a sr_rational. *