/** * @author (c) Eyal Rozenberg * 2021-2022, Haifa, Palestine/Israel * @author (c) Marco Paland (info@paland.com) * 2014-2019, PALANDesign Hannover, Germany * * @note Others have made smaller contributions to this file: see the * contributors page at https://github.com/eyalroz/printf/graphs/contributors * or ask one of the authors. * * @brief Small stand-alone implementation of the printf family of functions * (`(v)printf`, `(v)s(n)printf` etc., geared towards use on embedded systems with * a very limited resources. * * @note the implementations are thread-safe; re-entrant; use no functions from * the standard library; and do not dynamically allocate any memory. * * @license The MIT License (MIT) * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #ifndef PRINTF_H_ #define PRINTF_H_ #ifdef __cplusplus #include #include extern "C" { #else #include #include #endif #ifdef __GNUC__ #define ATTR_PRINTF(one_based_format_index, first_arg) \ __attribute__((format(__printf__, (one_based_format_index), (first_arg)))) #define ATTR_VPRINTF(one_based_format_index) ATTR_PRINTF((one_based_format_index), 0) #else #define ATTR_PRINTF((one_based_format_index), (first_arg)) #define ATTR_VPRINTF(one_based_format_index) #endif #ifndef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES #define PRINTF_ALIAS_STANDARD_FUNCTION_NAMES 0 #endif #if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES #define printf_ printf #define sprintf_ sprintf #define vsprintf_ vsprintf #define snprintf_ snprintf #define vsnprintf_ vsnprintf #define vprintf_ vprintf #endif // If you want to include this implementation file directly rather than // link against, this will let you control the functions' visibility, // e.g. make them static so as not to clash with other objects also // using them. #ifndef PRINTF_VISIBILITY #define PRINTF_VISIBILITY #endif /** * An implementation of the C standard's printf/vprintf * * @note you must implement a @ref putchar_ function for using this function - it invokes @ref putchar_ * rather than directly performing any I/O (which insulates it from any dependence on the operating system * and external libraries). * * @param format A string specifying the format of the output, with %-marked specifiers of how to interpret * additional arguments. * @param arg Additional arguments to the function, one for each %-specifier in @p format string * @return The number of characters written into @p s, not counting the terminating null character */ ///@{ PRINTF_VISIBILITY int printf_libinit(const char *format, ...) ATTR_PRINTF(1, 2); PRINTF_VISIBILITY int vprintf_libinit(const char *format, va_list arg) ATTR_VPRINTF(1); ///@} /** * An implementation of the C standard's sprintf/vsprintf * * @note For security considerations (the potential for exceeding the buffer bounds), please consider using * the size-constrained variant, @ref snprintf / @ref vsnprintf , instead. * * @param s An array in which to store the formatted string. It must be large enough to fit the formatted * output! * @param format A string specifying the format of the output, with %-marked specifiers of how to interpret * additional arguments. * @param arg Additional arguments to the function, one for each specifier in @p format * @return The number of characters written into @p s, not counting the terminating null character */ ///@{ PRINTF_VISIBILITY int sprintf_libinit(char *s, const char *format, ...) ATTR_PRINTF(2, 3); PRINTF_VISIBILITY int vsprintf_libinit(char *s, const char *format, va_list arg) ATTR_VPRINTF(2); ///@} /** * An implementation of the C standard's snprintf/vsnprintf * * @param s An array in which to store the formatted string. It must be large enough to fit either the * entire formatted output, or at least @p n characters. Alternatively, it can be NULL, in which case * nothing will be printed, and only the number of characters which _could_ have been printed is * tallied and returned. * @param n The maximum number of characters to write to the array, including a terminating null character * @param format A string specifying the format of the output, with %-marked specifiers of how to interpret * additional arguments. * @param arg Additional arguments to the function, one for each specifier in @p format * @return The number of characters that COULD have been written into @p s, not counting the terminating * null character. A value equal or larger than @p n indicates truncation. Only when the returned value * is non-negative and less than @p n, the null-terminated string has been fully and successfully printed. */ ///@{ PRINTF_VISIBILITY int snprintf_libinit(char *s, size_t count, const char *format, ...) ATTR_PRINTF(3, 4); PRINTF_VISIBILITY int vsnprintf_libinit(char *s, size_t count, const char *format, va_list arg) ATTR_VPRINTF(3); ///@} /** * printf/vprintf with user-specified output function * * An alternative to @ref printf_, in which the output function is specified dynamically * (rather than @ref putchar_ being used) * * @param out An output function which takes one character and a type-erased additional parameters * @param extra_arg The type-erased argument to pass to the output function @p out with each call * @param format A string specifying the format of the output, with %-marked specifiers of how to interpret * additional arguments. * @param arg Additional arguments to the function, one for each specifier in @p format * @return The number of characters for which the output f unction was invoked, not counting the terminating null character * */ PRINTF_VISIBILITY int fctprintf_libinit(void (*out)(char c, void *extra_arg), void *extra_arg, const char *format, ...) ATTR_PRINTF(3, 4); PRINTF_VISIBILITY int vfctprintf_libinit(void (*out)(char c, void *extra_arg), void *extra_arg, const char *format, va_list arg) ATTR_VPRINTF(3); #if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES #undef printf_ #undef sprintf_ #undef vsprintf_ #undef snprintf_ #undef vsnprintf_ #undef vprintf_ #endif #ifdef __cplusplus } #endif #endif // PRINTF_H_