X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Fpath-util.c;h=fd35e0c78671773b19583296bd52433a91968879;hp=2dddc8f2f689001e4b5dbd8dab206a9c01d5b508;hb=e1d758033dc7e101ab32323a0f1649d8daf56a22;hpb=1640a0b6b05b8ae01abbe5939f86f17a61e7998f diff --git a/src/shared/path-util.c b/src/shared/path-util.c index 2dddc8f2f..fd35e0c78 100644 --- a/src/shared/path-util.c +++ b/src/shared/path-util.c @@ -45,17 +45,6 @@ bool is_path(const char *p) { return !!strchr(p, '/'); } -char *path_get_file_name(const char *p) { - char *r; - - assert(p); - - if ((r = strrchr(p, '/'))) - return r + 1; - - return (char*) p; -} - int path_get_parent(const char *path, char **_r) { const char *e, *a = NULL, *b = NULL, *p; char *r; @@ -101,7 +90,8 @@ char **path_split_and_make_absolute(const char *p) { char **l; assert(p); - if (!(l = strv_split(p, ":"))) + l = strv_split(p, ":"); + if (!l) return NULL; if (!path_strv_make_absolute_cwd(l)) { @@ -125,7 +115,7 @@ char *path_make_absolute(const char *p, const char *prefix) { } char *path_make_absolute_cwd(const char *p) { - char *cwd, *r; + _cleanup_free_ char *cwd = NULL; assert(p); @@ -135,13 +125,96 @@ char *path_make_absolute_cwd(const char *p) { if (path_is_absolute(p)) return strdup(p); - if (!(cwd = get_current_dir_name())) + cwd = get_current_dir_name(); + if (!cwd) return NULL; - r = path_make_absolute(p, cwd); - free(cwd); + return path_make_absolute(p, cwd); +} + +int path_make_relative(const char *from_dir, const char *to_path, char **_r) { + char *r, *p; + unsigned n_parents; + + assert(from_dir); + assert(to_path); + assert(_r); + + /* Strips the common part, and adds ".." elements as necessary. */ + + if (!path_is_absolute(from_dir)) + return -EINVAL; + + if (!path_is_absolute(to_path)) + return -EINVAL; + + /* Skip the common part. */ + for (;;) { + size_t a; + size_t b; + + from_dir += strspn(from_dir, "/"); + to_path += strspn(to_path, "/"); + + if (!*from_dir) { + if (!*to_path) + /* from_dir equals to_path. */ + r = strdup("."); + else + /* from_dir is a parent directory of to_path. */ + r = strdup(to_path); + + if (!r) + return -ENOMEM; + + path_kill_slashes(r); + + *_r = r; + return 0; + } + + if (!*to_path) + break; + + a = strcspn(from_dir, "/"); + b = strcspn(to_path, "/"); + + if (a != b) + break; + + if (memcmp(from_dir, to_path, a) != 0) + break; + + from_dir += a; + to_path += b; + } + + /* If we're here, then "from_dir" has one or more elements that need to + * be replaced with "..". */ - return r; + /* Count the number of necessary ".." elements. */ + for (n_parents = 0;;) { + from_dir += strspn(from_dir, "/"); + + if (!*from_dir) + break; + + from_dir += strcspn(from_dir, "/"); + n_parents++; + } + + r = malloc(n_parents * 3 + strlen(to_path) + 1); + if (!r) + return -ENOMEM; + + for (p = r; n_parents > 0; n_parents--, p += 3) + memcpy(p, "../", 3); + + strcpy(p, to_path); + path_kill_slashes(r); + + *_r = r; + return 0; } char **path_strv_make_absolute_cwd(char **l) { @@ -154,7 +227,8 @@ char **path_strv_make_absolute_cwd(char **l) { STRV_FOREACH(s, l) { char *t; - if (!(t = path_make_absolute_cwd(*s))) + t = path_make_absolute_cwd(*s); + if (!t) return NULL; free(*s); @@ -164,7 +238,7 @@ char **path_strv_make_absolute_cwd(char **l) { return l; } -char **path_strv_canonicalize(char **l) { +char **path_strv_resolve(char **l, const char *prefix) { char **s; unsigned k = 0; bool enomem = false; @@ -178,25 +252,65 @@ char **path_strv_canonicalize(char **l) { STRV_FOREACH(s, l) { char *t, *u; + _cleanup_free_ char *orig = NULL; - t = path_make_absolute_cwd(*s); - free(*s); - - if (!t) { - enomem = true; + if (!path_is_absolute(*s)) { + free(*s); continue; } + if (prefix) { + orig = *s; + t = strappend(prefix, orig); + if (!t) { + enomem = true; + continue; + } + } else + t = *s; + errno = 0; u = canonicalize_file_name(t); - free(t); - if (!u) { - if (errno == ENOMEM || !errno) - enomem = true; - - continue; - } + if (errno == ENOENT) { + if (prefix) { + u = orig; + orig = NULL; + free(t); + } else + u = t; + } else { + free(t); + if (errno == ENOMEM || errno == 0) + enomem = true; + + continue; + } + } else if (prefix) { + char *x; + + free(t); + x = path_startswith(u, prefix); + if (x) { + /* restore the slash if it was lost */ + if (!startswith(x, "/")) + *(--x) = '/'; + + t = strdup(x); + free(u); + if (!t) { + enomem = true; + continue; + } + u = t; + } else { + /* canonicalized path goes outside of + * prefix, keep the original path instead */ + u = orig; + orig = NULL; + } + } else + free(t); l[k++] = u; } @@ -209,24 +323,15 @@ char **path_strv_canonicalize(char **l) { return l; } -char **path_strv_remove_empty(char **l) { - char **f, **t; - - if (!l) - return NULL; - - for (f = t = l; *f; f++) { +char **path_strv_resolve_uniq(char **l, const char *prefix) { - if (dir_is_empty(*f) > 0) { - free(*f); - continue; - } + if (strv_isempty(l)) + return l; - *(t++) = *f; - } + if (!path_strv_resolve(l, prefix)) + return NULL; - *t = NULL; - return l; + return strv_uniq(l); } char *path_kill_slashes(char *path) { @@ -264,12 +369,12 @@ char *path_kill_slashes(char *path) { return path; } -bool path_startswith(const char *path, const char *prefix) { +char* path_startswith(const char *path, const char *prefix) { assert(path); assert(prefix); if ((path[0] == '/') != (prefix[0] == '/')) - return false; + return NULL; for (;;) { size_t a, b; @@ -278,19 +383,19 @@ bool path_startswith(const char *path, const char *prefix) { prefix += strspn(prefix, "/"); if (*prefix == 0) - return true; + return (char*) path; if (*path == 0) - return false; + return NULL; a = strcspn(path, "/"); b = strcspn(prefix, "/"); if (a != b) - return false; + return NULL; if (memcmp(path, prefix, a) != 0) - return false; + return NULL; path += a; prefix += b; @@ -331,11 +436,15 @@ bool path_equal(const char *a, const char *b) { } int path_is_mount_point(const char *t, bool allow_symlink) { - char *parent; - int r; - struct file_handle *h; + + union file_handle_union h = { + .handle.handle_bytes = MAX_HANDLE_SZ + }; + int mount_id, mount_id_parent; + _cleanup_free_ char *parent = NULL; struct stat a, b; + int r; /* We are not actually interested in the file handles, but * name_to_handle_at() also passes us the mount ID, hence use @@ -344,13 +453,10 @@ int path_is_mount_point(const char *t, bool allow_symlink) { if (path_equal(t, "/")) return 1; - h = alloca(MAX_HANDLE_SZ); - h->handle_bytes = MAX_HANDLE_SZ; - - r = name_to_handle_at(AT_FDCWD, t, h, &mount_id, allow_symlink ? AT_SYMLINK_FOLLOW : 0); + r = name_to_handle_at(AT_FDCWD, t, &h.handle, &mount_id, allow_symlink ? AT_SYMLINK_FOLLOW : 0); if (r < 0) { - if (errno == ENOTSUP) - /* This file system does not support + if (IN_SET(errno, ENOSYS, EOPNOTSUPP)) + /* This kernel or file system does not support * name_to_handle_at(), hence fallback to the * traditional stat() logic */ goto fallback; @@ -365,15 +471,13 @@ int path_is_mount_point(const char *t, bool allow_symlink) { if (r < 0) return r; - h->handle_bytes = MAX_HANDLE_SZ; - r = name_to_handle_at(AT_FDCWD, parent, h, &mount_id_parent, 0); - free(parent); - + h.handle.handle_bytes = MAX_HANDLE_SZ; + r = name_to_handle_at(AT_FDCWD, parent, &h.handle, &mount_id_parent, 0); if (r < 0) { /* The parent can't do name_to_handle_at() but the * directory we are interested in can? If so, it must * be a mount point */ - if (errno == ENOTSUP) + if (errno == EOPNOTSUPP) return 1; return -errno; @@ -385,18 +489,20 @@ fallback: if (allow_symlink) r = stat(t, &a); else - r = lstat(t, &b); + r = lstat(t, &a); + + if (r < 0) { + if (errno == ENOENT) + return 0; - if (r < 0) return -errno; + } r = path_get_parent(t, &parent); if (r < 0) return r; r = lstat(parent, &b); - free(parent); - if (r < 0) return -errno; @@ -413,3 +519,115 @@ int path_is_read_only_fs(const char *path) { return !!(st.f_flag & ST_RDONLY); } + +int path_is_os_tree(const char *path) { + char *p; + int r; + + /* We use /usr/lib/os-release as flag file if something is an OS */ + p = strappenda(path, "/usr/lib/os-release"); + r = access(p, F_OK); + + if (r >= 0) + return 1; + + /* Also check for the old location in /etc, just in case. */ + p = strappenda(path, "/etc/os-release"); + r = access(p, F_OK); + + return r >= 0; +} + +int find_binary(const char *name, char **filename) { + assert(name); + + if (strchr(name, '/')) { + if (access(name, X_OK) < 0) + return -errno; + + if (filename) { + char *p; + + p = path_make_absolute_cwd(name); + if (!p) + return -ENOMEM; + + *filename = p; + } + + return 0; + } else { + const char *path; + char *state, *w; + size_t l; + + /** + * Plain getenv, not secure_getenv, because we want + * to actually allow the user to pick the binary. + */ + path = getenv("PATH"); + if (!path) + path = DEFAULT_PATH; + + FOREACH_WORD_SEPARATOR(w, l, path, ":", state) { + _cleanup_free_ char *p = NULL; + + if (asprintf(&p, "%.*s/%s", (int) l, w, name) < 0) + return -ENOMEM; + + if (access(p, X_OK) < 0) + continue; + + if (filename) { + *filename = path_kill_slashes(p); + p = NULL; + } + + return 0; + } + + return -ENOENT; + } +} + +bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool update) { + bool changed = false; + const char* const* i; + + assert(timestamp); + + if (paths == NULL) + return false; + + STRV_FOREACH(i, paths) { + struct stat stats; + usec_t u; + + if (stat(*i, &stats) < 0) + continue; + + u = timespec_load(&stats.st_mtim); + + /* first check */ + if (*timestamp >= u) + continue; + + log_debug("timestamp of '%s' changed", *i); + + /* update timestamp */ + if (update) { + *timestamp = u; + changed = true; + } else + return true; + } + + return changed; +} + +int fsck_exists(const char *fstype) { + const char *checker; + + checker = strappenda("fsck.", fstype); + return find_binary(checker, NULL); +}