diff options
Diffstat (limited to 'grub-core/gfxmenu/gui_string_util.c')
| -rw-r--r-- | grub-core/gfxmenu/gui_string_util.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/grub-core/gfxmenu/gui_string_util.c b/grub-core/gfxmenu/gui_string_util.c new file mode 100644 index 0000000..ba1e1ea --- /dev/null +++ b/grub-core/gfxmenu/gui_string_util.c @@ -0,0 +1,206 @@ +/* gui_string_util.c - String utilities used by the GUI system. */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2008,2009 Free Software Foundation, Inc. + * + * GRUB 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. + * + * GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <grub/gui_string_util.h> +#include <grub/types.h> +#include <grub/misc.h> +#include <grub/mm.h> + +/* Create a new NUL-terminated string on the heap as a substring of BUF. + The range of buf included is the half-open interval [START,END). + The index START is inclusive, END is exclusive. */ +char * +grub_new_substring (const char *buf, + grub_size_t start, grub_size_t end) +{ + if (end < start) + return 0; + grub_size_t len = end - start; + char *s = grub_malloc (len + 1); + if (! s) + return 0; + grub_memcpy (s, buf + start, len); + s[len] = '\0'; + return s; +} + +/* Eliminate "." and ".." path elements from PATH. A new heap-allocated + string is returned. */ +static char * +canonicalize_path (const char *path) +{ + int i; + const char *p; + char *newpath = 0; + + /* Count the path components in path. */ + int components = 1; + for (p = path; *p; p++) + if (*p == '/') + components++; + + char **path_array = grub_calloc (components, sizeof (*path_array)); + if (! path_array) + return 0; + + /* Initialize array elements to NULL pointers; in case once of the + allocations fails, the cleanup code can just call grub_free() for all + pointers in the array. */ + for (i = 0; i < components; i++) + path_array[i] = 0; + + /* Parse the path into path_array. */ + p = path; + for (i = 0; i < components && p; i++) + { + /* Find the end of the path element. */ + const char *end = grub_strchr (p, '/'); + if (!end) + end = p + grub_strlen (p); + + /* Copy the element. */ + path_array[i] = grub_new_substring (p, 0, end - p); + if (! path_array[i]) + goto cleanup; + + /* Advance p to point to the start of the next element, or NULL. */ + if (*end) + p = end + 1; + else + p = 0; + } + + /* Eliminate '.' and '..' elements from the path array. */ + int newpath_length = 0; + for (i = components - 1; i >= 0; --i) + { + if (! grub_strcmp (path_array[i], ".")) + { + grub_free (path_array[i]); + path_array[i] = 0; + } + else if (! grub_strcmp (path_array[i], "..") + && i > 0) + { + /* Delete the '..' and the prior path element. */ + grub_free (path_array[i]); + path_array[i] = 0; + --i; + grub_free (path_array[i]); + path_array[i] = 0; + } + else + { + newpath_length += grub_strlen (path_array[i]) + 1; + } + } + + /* Construct a new path string. */ + newpath = grub_malloc (newpath_length + 1); + if (! newpath) + goto cleanup; + + newpath[0] = '\0'; + char *newpath_end = newpath; + int first = 1; + for (i = 0; i < components; i++) + { + char *element = path_array[i]; + if (element) + { + /* For all components but the first, prefix with a slash. */ + if (! first) + newpath_end = grub_stpcpy (newpath_end, "/"); + newpath_end = grub_stpcpy (newpath_end, element); + first = 0; + } + } + +cleanup: + for (i = 0; i < components; i++) + grub_free (path_array[i]); + grub_free (path_array); + + return newpath; +} + +/* Return a new heap-allocated string representing to absolute path + to the file referred to by PATH. If PATH is an absolute path, then + the returned path is a copy of PATH. If PATH is a relative path, then + BASE is with PATH used to construct the absolute path. */ +char * +grub_resolve_relative_path (const char *base, const char *path) +{ + char *abspath; + char *canonpath; + char *p; + grub_size_t l; + + /* If PATH is an absolute path, then just use it as is. */ + if (path[0] == '/' || path[0] == '(') + return canonicalize_path (path); + + abspath = grub_malloc (grub_strlen (base) + grub_strlen (path) + 3); + if (! abspath) + return 0; + + /* Concatenate BASE and PATH. */ + p = grub_stpcpy (abspath, base); + l = grub_strlen (abspath); + if (l == 0 || abspath[l-1] != '/') + { + *p = '/'; + p++; + *p = 0; + } + grub_stpcpy (p, path); + + canonpath = canonicalize_path (abspath); + if (! canonpath) + return abspath; + + grub_free (abspath); + return canonpath; +} + +/* Get the path of the directory where the file at FILE_PATH is located. + FILE_PATH should refer to a file, not a directory. The returned path + includes a trailing slash. + This does not handle GRUB "(hd0,0)" paths properly yet since it only + looks at slashes. */ +char * +grub_get_dirname (const char *file_path) +{ + int i; + int last_slash; + + last_slash = -1; + for (i = grub_strlen (file_path) - 1; i >= 0; --i) + { + if (file_path[i] == '/') + { + last_slash = i; + break; + } + } + if (last_slash == -1) + return grub_strdup ("/"); + + return grub_new_substring (file_path, 0, last_slash + 1); +} |