diff options
| -rw-r--r-- | include/slibc-human.h | 21 | ||||
| -rw-r--r-- | src/slibc-human/humanmode.c | 75 |
2 files changed, 94 insertions, 2 deletions
diff --git a/include/slibc-human.h b/include/slibc-human.h index ee55568..4c98902 100644 --- a/include/slibc-human.h +++ b/include/slibc-human.h @@ -33,7 +33,10 @@ -enum machinemode_mode +/** + * Representation settings for file permissions. + */ +enum humanmode_mode { /** * Return in the format where 0750 @@ -182,7 +185,21 @@ enum unescape_mode -char* humanmode(char* restrict buffer, mode_t perm, enum machinemode_mode mode); +/** + * Convert file permission from machine representation to human representation. + * + * @param buffer Sufficiently large buffer for the output, or `NULL`. + * 18 characters is always sufficient, regardless of `mode`. + * @param perm Machine representation of the permissions, will be masked with 07777. + * @param mode Representation style, 0 for default. + * @return Human representation of the file permissions, `NULL` on error. + * On success, the caller is responsible for deallocating the + * returned pointer, if and only if `buffer` is `NULL`. + * + * @throws EINVAL If `mode` is invalid. + * @throws ENOMEM The process cannot allocate more memory. + */ +char* humanmode(char* restrict, mode_t, enum humanmode_mode); int machinemode(mode_t* restrict mode, mode_t* restrict mask, const char* restrict str); diff --git a/src/slibc-human/humanmode.c b/src/slibc-human/humanmode.c new file mode 100644 index 0000000..57b1534 --- /dev/null +++ b/src/slibc-human/humanmode.c @@ -0,0 +1,75 @@ +/** + * 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 <slib-human.h> +#include <stdlib.h> +#include <errno.h> + + + +/** + * Convert file permission from machine representation to human representation. + * + * @param buffer Sufficiently large buffer for the output, or `NULL`. + * 18 characters is always sufficient, regardless of `mode`. + * @param perm Machine representation of the permissions, will be masked with 07777. + * @param mode Representation style, 0 for default. + * @return Human representation of the file permissions, `NULL` on error. + * On success, the caller is responsible for deallocating the + * returned pointer, if and only if `buffer` is `NULL`. + * + * @throws EINVAL If `mode` is invalid. + * @throws ENOMEM The process cannot allocate more memory. + */ +char* humanmode(char* restrict buffer, mode_t perm, enum humanmode_mode mode) +{ + mode_t perm_ = perm | (mode != MACHINEMODE_MASK ? 07777 : 0); + int name = mode & MACHINEMODE_MASK; + char* w; + + if (mode & ~3) + return errno = EINVAL, NULL; + if (!mode) + mode = MACHINEMODE_STAT; + + if (buffer == NULL) + buffer = malloc((mode == MACHINEMODE_STAT ? 10 : 18) * sizeof(char)); + if (buffer == NULL) + return NULL; + w = buffer; + + if (name) *w++ = 'u', *w++ = '='; + if (perm_ & S_IRUSR) *w++ = (perm & S_IRUSR) ? 'r' : '-'; + if (perm_ & S_IWUSR) *w++ = (perm & S_IWUSR) ? 'w' : '-'; + if (perm & S_ISUID) *w++ = (perm & S_IXUSR) ? 's' : 'S'; + else if (perm_ & S_IXUSR) *w++ = (perm & S_IXUSR) ? 'x' : '-'; + + if (name) *w++ = ',', *w++ = 'g', *w++ = '='; + if (perm_ & S_IRGRP) *w++ = (perm & S_IRGRP) ? 'r' : '-'; + if (perm_ & S_IWGRP) *w++ = (perm & S_IWGRP) ? 'w' : '-'; + if (perm & S_ISGID) *w++ = (perm & S_IXGRP) ? 's' : 'S'; + else if (perm_ & S_IXGRP) *w++ = (perm & S_IXGRP) ? 'x' : '-'; + + if (name) *w++ = ',', *w++ = 'o', *w++ = '='; + if (perm_ & S_IROTH) *w++ = (perm & S_IROTH) ? 'r' : '-'; + if (perm_ & S_IWOTH) *w++ = (perm & S_IWOTH) ? 'w' : '-'; + if (perm & S_ISVTX) *w++ = (perm & S_IXOTH) ? 't' : 'T'; + else if (perm_ & S_IXOTH) *w++ = (perm & S_IXOTH) ? 'x' : '-'; + + return *w = 0, buffer; +} + |