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-rw-r--r--src/util.c510
1 files changed, 510 insertions, 0 deletions
diff --git a/src/util.c b/src/util.c
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+++ b/src/util.c
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+/****************************************************************************
+ * 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(&regex, 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;
+}
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