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| -rw-r--r-- | include/string.h | 119 | ||||
| -rw-r--r-- | src/string/strerror.c | 125 |
2 files changed, 244 insertions, 0 deletions
diff --git a/include/string.h b/include/string.h new file mode 100644 index 0000000..cd866a2 --- /dev/null +++ b/include/string.h @@ -0,0 +1,119 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef _STRING_H +#define _STRING_H +#include <slibc/version.h> + + + +#define __NEED_size_t +#define __NEED_locale_t /* TODO not defined */ + +#include <bits/types.h> + + + +/** + * Return a textual representation of an error code. + * This error code must from `errno`. + * + * This implementation of `strerror` cannot fail. however + * POSIX specifies that it can fail, any may only set `errno` + * if it does fail. You should therefore, set `errno` to + * zero before calling this function, and inspect `errno` + * when it returns, as there is no reserved return value + * that indicates and error. + * + * The returned value must not be modified or freed. + * + * As a slibc-specific modification, this function is MT-Safe. + * + * @param errnum The error code. + * @return A description of the error. + */ +char* strerror(int) + __GCC_ONLY(__attribute__((returns_nonnull))); + +/** + * Return a textual representation of an error code. + * This error code must from `errno`. + * + * POSIX specifies `errno` may only be set on failure, + * and reserves no return value to indicate such. + * You should therefore, set `errno` to zero before calling + * this function, and inspect `errno` when it returns. + * + * The returned value must not be modified or freed. + * + * As a slibc-specific modification, this function is MT-Safe. + * + * @param errnum The error code. + * @param locale The locale, must be a valid locale and not + * `LC_GLOBAL_LOCALE`, lest the behaviour is undefined. + * @return A description of the error. + */ +char* strerror_l(int, locale_t); + + +#ifndef _PORTABLE_SOURCE +/** + * Reenterant variant of `stderror`. + * + * This is an XSI-compliant extension. However the name + * is not part of the XSI specification, `strerror_r` + * should be used. It is defined to this function if + * `(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !_GNU_SOURCE`. + * + * @param errnum The error code. + * @param buf Buffer where the description shall be stored. + * @param buflen The allocation size of `buf`. + * @return Zero on success, value for `errno` on error + * + * @throws ERANGE `buf` was too small to store the description. + */ +int __xsi_strerror_r(int, char*, size_t); /* XSI-compliant strerror_r */ + +/** + * Reenterant variant of `stderror`. + * + * This is a GNU-specific extension. However the name + * is not part of the GNU specification, `strerror_r` should + * be used. It is defined to this function unless + * `(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !_GNU_SOURCE`. + * + * @param errnum The error code. + * @param buf Buffer where the description shall be stored. + * @param buflen The allocation size of `buf`. + * @return `buf` on success, `NULL` on error. On error, `errno` + * is set to indicate the error. + * + * @throws ERANGE `buf` was too small to store the description. + */ +char* __gnu_strerror_r(int, char*, size_t); /* GNU-specific strerror_r */ + +# if (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE) +# define strerror_r __xsi_strerror_r +# else +# define strerror_r __gnu_strerror_r +# endif +#endif + + + +#endif + diff --git a/src/string/strerror.c b/src/string/strerror.c new file mode 100644 index 0000000..417d622 --- /dev/null +++ b/src/string/strerror.c @@ -0,0 +1,125 @@ +/** + * slibc — Yet another C library + * Copyright © 2015 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <string.h> + + +/** + * Return a textual representation of an error code. + * This error code must from `errno`. + * + * This implementation of `strerror` cannot fail. however + * POSIX specifies that it can fail, any may only set `errno` + * if it does fail. You should therefore, set `errno` to + * zero before calling this function, and inspect `errno` + * when it returns, as there is no reserved return value + * that indicates and error. + * + * The returned value must not be modified or freed. + * + * As a slibc-specific modification, this function is MT-Safe. + * + * @param errnum The error code. + * @return A description of the error. + */ +char* strerror(int errnum) +{ + return strerror_l(errnum, CURRENT_LOCALE /* TODO not defined */); +} + + +/** + * Return a textual representation of an error code. + * This error code must from `errno`. + * + * POSIX specifies `errno` may only be set on failure, + * and reserves no return value to indicate such. + * You should therefore, set `errno` to zero before calling + * this function, and inspect `errno` when it returns. + * + * The returned value must not be modified or freed. + * + * As a slibc-specific modification, this function is MT-Safe. + * + * @param errnum The error code. + * @param locale The locale, must be a valid locale and not + * `LC_GLOBAL_LOCALE`, lest the behaviour is undefined. + * @return A description of the error. + */ +char* strerror_l(int errnum, locale_t locale) +{ + /* TODO implement strerror_l */ + return (void) errnum, (void) locale, NULL: +} + + +/** + * Reenterant variant of `stderror`. + * + * This is an XSI-compliant extension. However the name + * is not part of the XSI specification, `strerror_r` + * should be used. It is defined to this function if + * `(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !_GNU_SOURCE`. + * + * @param errnum The error code. + * @param buf Buffer where the description shall be stored. + * @param buflen The allocation size of `buf`. + * @return Zero on success, value for `errno` on error + * + * @throws ERANGE `buf` was too small to store the description. + */ +int __xsi_strerror_r(int errnum, char* buf, size_t buflen) +{ + char* description = strerror(errnum); + size_t length = strlen(description); + + if (buflen == 0) + return ERANGE; + + if (buflen <= length) + { + memcpy(buf, description, buflen - 1); + buf[buflen - 1] = 0; + return ERANGE; + } + + return memcpy(buf, description, length + 1), 0; +} + + +/** + * Reenterant variant of `stderror`. + * + * This is a GNU-specific extension. However the name + * is not part of the GNU specification, `strerror_r` should + * be used. It is defined to this function unless + * `(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !_GNU_SOURCE`. + * + * @param errnum The error code. + * @param buf Buffer where the description shall be stored. + * @param buflen The allocation size of `buf`. + * @return `buf` on success, `NULL` on error. On error, `errno` + * is set to indicate the error. + * + * @throws ERANGE `buf` was too small to store the description. + */ +char* __gnu_strerror_r(int errnum, char* buf, size_t buflen) +{ + errno = __xsi_strerror_r(errnum, buf, buflen); + return errno ? NULL : buf; +} + |