diff options
Diffstat (limited to 'src/util.c')
-rw-r--r-- | src/util.c | 510 |
1 files changed, 510 insertions, 0 deletions
diff --git a/src/util.c b/src/util.c new file mode 100644 index 0000000..a62e66c --- /dev/null +++ b/src/util.c @@ -0,0 +1,510 @@ +/**************************************************************************** + * 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. * + ****************************************************************************/ + +#include "util.h" +#include "dstring.h" +#include "xregex.h" +#include <assert.h> +#include <errno.h> +#include <fcntl.h> +#include <langinfo.h> +#include <nl_types.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> +#include <wchar.h> + +#if BFS_HAS_SYS_PARAM +# include <sys/param.h> +#endif + +#if BFS_HAS_SYS_SYSMACROS +# include <sys/sysmacros.h> +#elif BFS_HAS_SYS_MKDEV +# include <sys/mkdev.h> +#endif + +#if BFS_HAS_UTIL +# include <util.h> +#endif + +char *xreadlinkat(int fd, const char *path, size_t size) { + ssize_t len; + char *name = NULL; + + if (size == 0) { + size = 64; + } else { + ++size; // NUL terminator + } + + while (true) { + char *new_name = realloc(name, size); + if (!new_name) { + goto error; + } + name = new_name; + + len = readlinkat(fd, path, name, size); + if (len < 0) { + goto error; + } else if ((size_t)len >= size) { + size *= 2; + } else { + break; + } + } + + name[len] = '\0'; + return name; + +error: + free(name); + return NULL; +} + +int dup_cloexec(int fd) { +#ifdef F_DUPFD_CLOEXEC + return fcntl(fd, F_DUPFD_CLOEXEC, 0); +#else + int ret = dup(fd); + if (ret < 0) { + return -1; + } + + if (fcntl(ret, F_SETFD, FD_CLOEXEC) == -1) { + close_quietly(ret); + return -1; + } + + return ret; +#endif +} + +int pipe_cloexec(int pipefd[2]) { +#if __linux__ || (BSD && !__APPLE__) + return pipe2(pipefd, O_CLOEXEC); +#else + if (pipe(pipefd) != 0) { + return -1; + } + + if (fcntl(pipefd[0], F_SETFD, FD_CLOEXEC) == -1 || fcntl(pipefd[1], F_SETFD, FD_CLOEXEC) == -1) { + close_quietly(pipefd[1]); + close_quietly(pipefd[0]); + return -1; + } + + return 0; +#endif +} + +/** Get the single character describing the given file type. */ +static char type_char(mode_t mode) { + switch (mode & S_IFMT) { + case S_IFREG: + return '-'; + case S_IFBLK: + return 'b'; + case S_IFCHR: + return 'c'; + case S_IFDIR: + return 'd'; + case S_IFLNK: + return 'l'; + case S_IFIFO: + return 'p'; + case S_IFSOCK: + return 's'; +#ifdef S_IFDOOR + case S_IFDOOR: + return 'D'; +#endif +#ifdef S_IFPORT + case S_IFPORT: + return 'P'; +#endif +#ifdef S_IFWHT + case S_IFWHT: + return 'w'; +#endif + } + + return '?'; +} + +void xstrmode(mode_t mode, char str[11]) { + strcpy(str, "----------"); + + str[0] = type_char(mode); + + if (mode & 00400) { + str[1] = 'r'; + } + if (mode & 00200) { + str[2] = 'w'; + } + if ((mode & 04100) == 04000) { + str[3] = 'S'; + } else if (mode & 04000) { + str[3] = 's'; + } else if (mode & 00100) { + str[3] = 'x'; + } + + if (mode & 00040) { + str[4] = 'r'; + } + if (mode & 00020) { + str[5] = 'w'; + } + if ((mode & 02010) == 02000) { + str[6] = 'S'; + } else if (mode & 02000) { + str[6] = 's'; + } else if (mode & 00010) { + str[6] = 'x'; + } + + if (mode & 00004) { + str[7] = 'r'; + } + if (mode & 00002) { + str[8] = 'w'; + } + if ((mode & 01001) == 01000) { + str[9] = 'T'; + } else if (mode & 01000) { + str[9] = 't'; + } else if (mode & 00001) { + str[9] = 'x'; + } +} + +const char *xbasename(const char *path) { + const char *i; + + // Skip trailing slashes + for (i = path + strlen(path); i > path && i[-1] == '/'; --i); + + // Find the beginning of the name + for (; i > path && i[-1] != '/'; --i); + + // Skip leading slashes + for (; i[0] == '/' && i[1]; ++i); + + return i; +} + +int xfaccessat(int fd, const char *path, int amode) { + int ret = faccessat(fd, path, amode, 0); + +#ifdef AT_EACCESS + // Some platforms, like Hurd, only support AT_EACCESS. Other platforms, + // like Android, don't support AT_EACCESS at all. + if (ret != 0 && (errno == EINVAL || errno == ENOTSUP)) { + ret = faccessat(fd, path, amode, AT_EACCESS); + } +#endif + + return ret; +} + +int xstrtofflags(const char **str, unsigned long long *set, unsigned long long *clear) { +#if BSD && !__GNU__ + char *str_arg = (char *)*str; + unsigned long set_arg = 0; + unsigned long clear_arg = 0; + +#if __NetBSD__ + int ret = string_to_flags(&str_arg, &set_arg, &clear_arg); +#else + int ret = strtofflags(&str_arg, &set_arg, &clear_arg); +#endif + + *str = str_arg; + *set = set_arg; + *clear = clear_arg; + + if (ret != 0) { + errno = EINVAL; + } + return ret; +#else // !BSD + errno = ENOTSUP; + return -1; +#endif +} + +size_t xstrwidth(const char *str) { + size_t len = strlen(str); + size_t ret = 0; + + mbstate_t mb; + memset(&mb, 0, sizeof(mb)); + + while (len > 0) { + wchar_t wc; + size_t mblen = mbrtowc(&wc, str, len, &mb); + int cwidth; + if (mblen == (size_t)-1) { + // Invalid byte sequence, assume a single-width '?' + mblen = 1; + cwidth = 1; + memset(&mb, 0, sizeof(mb)); + } else if (mblen == (size_t)-2) { + // Incomplete byte sequence, assume a single-width '?' + mblen = len; + cwidth = 1; + } else { + cwidth = wcwidth(wc); + if (cwidth < 0) { + cwidth = 0; + } + } + + str += mblen; + len -= mblen; + ret += cwidth; + } + + return ret; +} + +bool is_nonexistence_error(int error) { + return error == ENOENT || errno == ENOTDIR; +} + +/** Compile and execute a regular expression for xrpmatch(). */ +static int xrpregex(nl_item item, const char *response) { + const char *pattern = nl_langinfo(item); + if (!pattern) { + return -1; + } + + struct bfs_regex *regex; + int ret = bfs_regcomp(®ex, pattern, BFS_REGEX_POSIX_EXTENDED, 0); + if (ret == 0) { + ret = bfs_regexec(regex, response, 0); + } + + bfs_regfree(regex); + return ret; +} + +/** Check if a response is affirmative or negative. */ +static int xrpmatch(const char *response) { + int ret = xrpregex(NOEXPR, response); + if (ret > 0) { + return 0; + } else if (ret < 0) { + return -1; + } + + ret = xrpregex(YESEXPR, response); + if (ret > 0) { + return 1; + } else if (ret < 0) { + return -1; + } + + // Failsafe: always handle y/n + char c = response[0]; + if (c == 'n' || c == 'N') { + return 0; + } else if (c == 'y' || c == 'Y') { + return 1; + } else { + return -1; + } +} + +int ynprompt(void) { + fflush(stderr); + + char *line = xgetdelim(stdin, '\n'); + int ret = line ? xrpmatch(line) : -1; + free(line); + return ret; +} + +dev_t bfs_makedev(int ma, int mi) { +#ifdef makedev + return makedev(ma, mi); +#else + return (ma << 8) | mi; +#endif +} + +int bfs_major(dev_t dev) { +#ifdef major + return major(dev); +#else + return dev >> 8; +#endif +} + +int bfs_minor(dev_t dev) { +#ifdef minor + return minor(dev); +#else + return dev & 0xFF; +#endif +} + +size_t xread(int fd, void *buf, size_t nbytes) { + size_t count = 0; + + while (count < nbytes) { + ssize_t ret = read(fd, (char *)buf + count, nbytes - count); + if (ret < 0) { + if (errno == EINTR) { + continue; + } else { + break; + } + } else if (ret == 0) { + // EOF + errno = 0; + break; + } else { + count += ret; + } + } + + return count; +} + +size_t xwrite(int fd, const void *buf, size_t nbytes) { + size_t count = 0; + + while (count < nbytes) { + ssize_t ret = write(fd, (const char *)buf + count, nbytes - count); + if (ret < 0) { + if (errno == EINTR) { + continue; + } else { + break; + } + } else if (ret == 0) { + // EOF? + errno = 0; + break; + } else { + count += ret; + } + } + + return count; +} + +char *xconfstr(int name) { + size_t len = confstr(name, NULL, 0); + if (len == 0) { + return NULL; + } + + char *str = malloc(len); + if (!str) { + return NULL; + } + + if (confstr(name, str, len) != len) { + free(str); + return NULL; + } + + return str; +} + +char *xgetdelim(FILE *file, char delim) { + char *chunk = NULL; + size_t n = 0; + ssize_t len = getdelim(&chunk, &n, delim, file); + if (len >= 0) { + if (chunk[len] == delim) { + chunk[len] = '\0'; + } + return chunk; + } else { + free(chunk); + if (!ferror(file)) { + errno = 0; + } + return NULL; + } +} + +FILE *xfopen(const char *path, int flags) { + char mode[4]; + + switch (flags & O_ACCMODE) { + case O_RDONLY: + strcpy(mode, "rb"); + break; + case O_WRONLY: + strcpy(mode, "wb"); + break; + case O_RDWR: + strcpy(mode, "r+b"); + break; + default: + assert(!"Invalid access mode"); + errno = EINVAL; + return NULL; + } + + if (flags & O_APPEND) { + mode[0] = 'a'; + } + + int fd; + if (flags & O_CREAT) { + fd = open(path, flags, 0666); + } else { + fd = open(path, flags); + } + + if (fd < 0) { + return NULL; + } + + FILE *ret = fdopen(fd, mode); + if (!ret) { + close_quietly(fd); + return NULL; + } + + return ret; +} + +int xclose(int fd) { + int ret = close(fd); + if (ret != 0) { + assert(errno != EBADF); + } + return ret; +} + +void close_quietly(int fd) { + int error = errno; + xclose(fd); + errno = error; +} |