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Diffstat (limited to 'src/util.h')
| -rw-r--r-- | src/util.h | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/src/util.h b/src/util.h new file mode 100644 index 0000000..b5c7d80 --- /dev/null +++ b/src/util.h @@ -0,0 +1,317 @@ +/**************************************************************************** + * bfs * + * Copyright (C) 2016-2022 Tavian Barnes <tavianator@tavianator.com> * + * * + * Permission to use, copy, modify, and/or distribute this software for any * + * purpose with or without fee is hereby granted. * + * * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * + ****************************************************************************/ + +/** + * Assorted utilities that don't belong anywhere else. + */ + +#ifndef BFS_UTIL_H +#define BFS_UTIL_H + +#include <fcntl.h> +#include <fnmatch.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdio.h> +#include <sys/types.h> + +// Some portability concerns + +#ifdef __has_feature +# define BFS_HAS_FEATURE(feature, fallback) __has_feature(feature) +#else +# define BFS_HAS_FEATURE(feature, fallback) fallback +#endif + +#ifdef __has_include +# define BFS_HAS_INCLUDE(header, fallback) __has_include(header) +#else +# define BFS_HAS_INCLUDE(header, fallback) fallback +#endif + +#ifdef __has_c_attribute +# define BFS_HAS_C_ATTRIBUTE(attr) __has_c_attribute(attr) +#else +# define BFS_HAS_C_ATTRIBUTE(attr) false +#endif + +#if __GNUC__ && defined(__has_attribute) +# define BFS_HAS_GNU_ATTRIBUTE(attr) __has_attribute(attr) +#else +# define BFS_HAS_GNU_ATTRIBUTE(attr) false +#endif + +#ifndef BFS_HAS_MNTENT +# define BFS_HAS_MNTENT BFS_HAS_INCLUDE(<mntent.h>, __GLIBC__) +#endif + +#ifndef BFS_HAS_SYS_ACL +# define BFS_HAS_SYS_ACL BFS_HAS_INCLUDE(<sys/acl.h>, true) +#endif + +#ifndef BFS_HAS_SYS_CAPABILITY +# define BFS_HAS_SYS_CAPABILITY BFS_HAS_INCLUDE(<sys/capability.h>, __linux__) +#endif + +#ifndef BFS_HAS_SYS_EXTATTR +# define BFS_HAS_SYS_EXTATTR BFS_HAS_INCLUDE(<sys/extattr.h>, __FreeBSD__) +#endif + +#ifndef BFS_HAS_SYS_MKDEV +# define BFS_HAS_SYS_MKDEV BFS_HAS_INCLUDE(<sys/mkdev.h>, false) +#endif + +#ifndef BFS_HAS_SYS_PARAM +# define BFS_HAS_SYS_PARAM BFS_HAS_INCLUDE(<sys/param.h>, true) +#endif + +#ifndef BFS_HAS_SYS_SYSMACROS +# define BFS_HAS_SYS_SYSMACROS BFS_HAS_INCLUDE(<sys/sysmacros.h>, __GLIBC__) +#endif + +#ifndef BFS_HAS_SYS_XATTR +# define BFS_HAS_SYS_XATTR BFS_HAS_INCLUDE(<sys/xattr.h>, __linux__) +#endif + +#ifndef BFS_HAS_UTIL +# define BFS_HAS_UTIL BFS_HAS_INCLUDE(<util.h>, __NetBSD__) +#endif + +#if !defined(FNM_CASEFOLD) && defined(FNM_IGNORECASE) +# define FNM_CASEFOLD FNM_IGNORECASE +#endif + +#ifndef O_DIRECTORY +# define O_DIRECTORY 0 +#endif + +#if BFS_HAS_C_ATTRIBUTE(fallthrough) +# define BFS_FALLTHROUGH [[fallthrough]] +#elif BFS_HAS_GNU_ATTRIBUTE(fallthrough) +# define BFS_FALLTHROUGH __attribute__((fallthrough)) +#else +# define BFS_FALLTHROUGH ((void)0) +#endif + +/** + * Adds compiler warnings for bad printf()-style function calls, if supported. + */ +#if BFS_HAS_GNU_ATTRIBUTE(format) +# define BFS_FORMATTER(fmt, args) __attribute__((format(printf, fmt, args))) +#else +# define BFS_FORMATTER(fmt, args) +#endif + +// Lower bound on BFS_FLEX_SIZEOF() +#define BFS_FLEX_LB(type, member, length) (offsetof(type, member) + sizeof(((type *)NULL)->member[0]) * (length)) + +// Maximum macro for BFS_FLEX_SIZE() +#define BFS_FLEX_MAX(a, b) ((a) > (b) ? (a) : (b)) + +/** + * Computes the size of a struct containing a flexible array member of the given + * length. + * + * @param type + * The type of the struct containing the flexible array. + * @param member + * The name of the flexible array member. + * @param length + * The length of the flexible array. + */ +#define BFS_FLEX_SIZEOF(type, member, length) \ + (sizeof(type) <= BFS_FLEX_LB(type, member, 0) \ + ? BFS_FLEX_LB(type, member, length) \ + : BFS_FLEX_MAX(sizeof(type), BFS_FLEX_LB(type, member, length))) + +/** + * readlinkat() wrapper that dynamically allocates the result. + * + * @param fd + * The base directory descriptor. + * @param path + * The path to the link, relative to fd. + * @param size + * An estimate for the size of the link name (pass 0 if unknown). + * @return The target of the link, allocated with malloc(), or NULL on failure. + */ +char *xreadlinkat(int fd, const char *path, size_t size); + +/** + * Like dup(), but set the FD_CLOEXEC flag. + * + * @param fd + * The file descriptor to duplicate. + * @return A duplicated file descriptor, or -1 on failure. + */ +int dup_cloexec(int fd); + +/** + * Like pipe(), but set the FD_CLOEXEC flag. + * + * @param pipefd + * The array to hold the two file descriptors. + * @return 0 on success, -1 on failure. + */ +int pipe_cloexec(int pipefd[2]); + +/** + * Format a mode like ls -l (e.g. -rw-r--r--). + * + * @param mode + * The mode to format. + * @param str + * The string to hold the formatted mode. + */ +void xstrmode(mode_t mode, char str[11]); + +/** + * basename() variant that doesn't modify the input. + * + * @param path + * The path in question. + * @return A pointer into path at the base name offset. + */ +const char *xbasename(const char *path); + +/** + * Wrapper for faccessat() that handles some portability issues. + */ +int xfaccessat(int fd, const char *path, int amode); + +/** + * Portability wrapper for strtofflags(). + * + * @param str + * The string to parse. The pointee will be advanced to the first + * invalid position on error. + * @param set + * The flags that are set in the string. + * @param clear + * The flags that are cleared in the string. + * @return + * 0 on success, -1 on failure. + */ +int xstrtofflags(const char **str, unsigned long long *set, unsigned long long *clear); + +/** + * wcswidth() variant that works on narrow strings. + * + * @param str + * The string to measure. + * @return + * The likely width of that string in a terminal. + */ +size_t xstrwidth(const char *str); + +/** + * Return whether an error code is due to a path not existing. + */ +bool is_nonexistence_error(int error); + +/** + * Process a yes/no prompt. + * + * @return 1 for yes, 0 for no, and -1 for unknown. + */ +int ynprompt(void); + +/** + * Portable version of makedev(). + */ +dev_t bfs_makedev(int ma, int mi); + +/** + * Portable version of major(). + */ +int bfs_major(dev_t dev); + +/** + * Portable version of minor(). + */ +int bfs_minor(dev_t dev); + +/** + * A safe version of read() that handles interrupted system calls and partial + * reads. + * + * @return + * The number of bytes read. A value != nbytes indicates an error + * (errno != 0) or end of file (errno == 0). + */ +size_t xread(int fd, void *buf, size_t nbytes); + +/** + * A safe version of write() that handles interrupted system calls and partial + * writes. + * + * @return + The number of bytes written. A value != nbytes indicates an error. + */ +size_t xwrite(int fd, const void *buf, size_t nbytes); + +/** + * Wrapper for confstr() that allocates with malloc(). + * + * @param name + * The ID of the confstr to look up. + * @return + * The value of the confstr, or NULL on failure. + */ +char *xconfstr(int name); + +/** + * Convenience wrapper for getdelim(). + * + * @param file + * The file to read. + * @param delim + * The delimiter character to split on. + * @return + * The read chunk (without the delimiter), allocated with malloc(). + * NULL is returned on error (errno != 0) or end of file (errno == 0). + */ +char *xgetdelim(FILE *file, char delim); + +/** + * fopen() variant that takes open() style flags. + * + * @param path + * The path to open. + * @param flags + * Flags to pass to open(). + */ +FILE *xfopen(const char *path, int flags); + +/** + * close() wrapper that asserts the file descriptor is valid. + * + * @param fd + * The file descriptor to close. + * @return + * 0 on success, or -1 on error. + */ +int xclose(int fd); + +/** + * close() variant that preserves errno. + * + * @param fd + * The file descriptor to close. + */ +void close_quietly(int fd); + +#endif // BFS_UTIL_H |