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IABSD.fr/xenocara/lib/xcb-util-xrm/src/database.c
jasper
- lib/xcb-util-xrm/src/database.c
-
/* * vim:ts=4:sw=4:expandtab * * Copyright © 2016 Ingo Bürk * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * * Except as contained in this notice, the names of the authors or their * institutions shall not be used in advertising or otherwise to promote the * sale, use or other dealings in this Software without prior written * authorization from the authors. * */ #include "externals.h" #include "database.h" #include "match.h" #include "util.h" #ifndef MAX_INCLUDE_DEPTH /* We want to limit the maximum depth of (recursive) #include directives. This * is to avoid accidental cyclic inclusions which would lead to an endless loop * otherwise. */ #define MAX_INCLUDE_DEPTH 100 #endif /* Forward declarations */ static xcb_xrm_database_t *__xcb_xrm_database_from_string(const char *_str, const char *base, int depth); static xcb_xrm_database_t *__xcb_xrm_database_from_file(const char *_filename, const char *base, int depth); static void __xcb_xrm_database_put(xcb_xrm_database_t *database, xcb_xrm_entry_t *entry, bool override); /* * Creates a database similarly to XGetDefault(). For typical applications, * this is the recommended way to construct the resource database. * * The database is created as follows: * - If the RESOURCE_MANAGER property exists on the root window of * screen 0, the database is constructed from it using @ref * xcb_xrm_database_from_resource_manager(). * - Otherwise, if $HOME/.Xresources exists, the database is constructed from * it using @ref xcb_xrm_database_from_file(). * - Otherwise, if $HOME/.Xdefaults exists, the database is constructed from * it using @ref xcb_xrm_database_from_file(). * - If the environment variable XENVIRONMENT is set, the file specified by * it is loaded using @ref xcb_xrm_database_from_file and then combined with * the database using @ref xcb_xrm_database_combine() with override set to * true. * If XENVIRONMENT is not specified, the same is done with * $HOME/.Xdefaults-$HOSTNAME, wherein $HOSTNAME is determined by * gethostname(2). * * This represents the way XGetDefault() creates the database for the most * part, but is not exactly the same. In particular, XGetDefault() does not * consider $HOME/.Xresources. * * @param conn XCB connection. * @returns The constructed database. Can return NULL, e.g., if the screen * cannot be determined. */ xcb_xrm_database_t *xcb_xrm_database_from_default(xcb_connection_t *conn) { xcb_screen_t *screen; xcb_xrm_database_t *database; char *xenvironment; screen = xcb_aux_get_screen(conn, 0); if (screen == NULL) return NULL; /* 1. Try to load the database from RESOURCE_MANAGER. */ database = xcb_xrm_database_from_resource_manager(conn, screen); /* 2. Otherwise, try to load the database from $HOME/.Xresources. */ if (database == NULL) { char *xresources = get_home_dir_file(".Xresources"); database = xcb_xrm_database_from_file(xresources); FREE(xresources); } /* 3. Otherwise, try to load the database from $HOME/.Xdefaults. */ if (database == NULL) { char *xdefaults = get_home_dir_file(".Xdefaults"); database = xcb_xrm_database_from_file(xdefaults); FREE(xdefaults); } /* 4. If XENVIRONMENT is specified, merge the database defined by that file. * Otherwise, use $HOME/.Xdefaults-$HOSTNAME. */ if ((xenvironment = getenv("XENVIRONMENT")) != NULL) { xcb_xrm_database_t *source = xcb_xrm_database_from_file(xenvironment); xcb_xrm_database_combine(source, &database, true); xcb_xrm_database_free(source); } else { char hostname[1024]; hostname[1023] = '\0'; if (gethostname(hostname, 1023) == 0) { char *name; if (asprintf(&name, ".Xdefaults-%s", hostname) >= 0) { xcb_xrm_database_t *source; char *xdefaults = get_home_dir_file(name); FREE(name); source = xcb_xrm_database_from_file(xdefaults); FREE(xdefaults); xcb_xrm_database_combine(source, &database, true); xcb_xrm_database_free(source); } } } return database; } /* * Loads the RESOURCE_MANAGER property and creates a database with its * contents. If the database could not be created, this function will return * NULL. * * @param conn A working XCB connection. * @param screen The xcb_screen_t* screen to use. * @returns The database described by the RESOURCE_MANAGER property. * * @ingroup xcb_xrm_database_t */ xcb_xrm_database_t *xcb_xrm_database_from_resource_manager(xcb_connection_t *conn, xcb_screen_t *screen) { xcb_xrm_database_t *database; char *resources = xcb_util_get_property(conn, screen->root, XCB_ATOM_RESOURCE_MANAGER, XCB_ATOM_STRING, 16 * 1024); if (resources == NULL) { return NULL; } /* Parse the resource string. */ database = xcb_xrm_database_from_string(resources); FREE(resources); return database; } /* * Creates a database from the given string. * If the database could not be created, this function will return NULL. * * @param str The resource string. * @returns The database described by the resource string. * * @ingroup xcb_xrm_database_t */ xcb_xrm_database_t *xcb_xrm_database_from_string(const char *str) { return __xcb_xrm_database_from_string(str, NULL, 0); } static xcb_xrm_database_t *__xcb_xrm_database_from_string(const char *_str, const char *base, int depth) { xcb_xrm_database_t *database; char *str; int num_continuations = 0; char *str_continued; char *outwalk; char *saveptr = NULL; if (_str == NULL) return xcb_xrm_database_from_string(""); str = strdup(_str); if (str == NULL) return NULL; /* Count the number of line continuations. */ for (char *walk = str; *walk != '\0'; walk++) { if (*walk == '\\' && *(walk + 1) == '\n') { num_continuations++; } } /* Take care of line continuations. */ str_continued = calloc(1, strlen(str) + 1 - 2 * num_continuations); if (str_continued == NULL) { FREE(str); return NULL; } outwalk = str_continued; for (char *walk = str; *walk != '\0'; walk++) { if (*walk == '\\' && *(walk + 1) == '\n') { walk++; continue; } *(outwalk++) = *walk; } *outwalk = '\0'; database = calloc(1, sizeof(struct xcb_xrm_database_t)); if (database == NULL) { FREE(str); FREE(str_continued); return NULL; } TAILQ_INIT(database); for (char *line = strtok_r(str_continued, "\n", &saveptr); line != NULL; line = strtok_r(NULL, "\n", &saveptr)) { /* Handle include directives. */ if (line[0] == '#') { int i = 1; /* Skip whitespace and quotes. */ while (line[i] == ' ' || line[i] == '\t') i++; if (depth < MAX_INCLUDE_DEPTH && line[i++] == 'i' && line[i++] == 'n' && line[i++] == 'c' && line[i++] == 'l' && line[i++] == 'u' && line[i++] == 'd' && line[i++] == 'e') { xcb_xrm_database_t *included; char *filename; char *copy; char *new_base; int j = strlen(line) - 1; /* Skip whitespace and quotes. */ while (line[i] == ' ' || line[i] == '\t' || line[i] == '"') i++; while (line[j] == ' ' || line[j] == '\t' || line[j] == '"') j--; if (j < i) { /* Only whitespace left in this line. */ continue; } line[j+1] = '\0'; filename = resolve_path(&line[i], base); if (filename == NULL) continue; /* We need to strdup() the filename since dirname() will modify it. */ copy = strdup(filename); if (copy == NULL) { FREE(filename); continue; } new_base = dirname(copy); if (new_base == NULL) { FREE(filename); FREE(copy); continue; } included = __xcb_xrm_database_from_file(filename, new_base, depth + 1); FREE(filename); FREE(copy); if (included != NULL) { xcb_xrm_database_combine(included, &database, true); xcb_xrm_database_free(included); } continue; } } xcb_xrm_database_put_resource_line(&database, line); } FREE(str); FREE(str_continued); return database; } /* * Creates a database from a given file. * If the file cannot be found or opened, NULL is returned. * * @param filename Valid filename. * @returns The database described by the file's contents. */ xcb_xrm_database_t *xcb_xrm_database_from_file(const char *filename) { return __xcb_xrm_database_from_file(filename, NULL, 0); } static xcb_xrm_database_t *__xcb_xrm_database_from_file(const char *_filename, const char *base, int depth) { char *filename = NULL; char *copy = NULL; char *new_base = NULL; char *content = NULL; xcb_xrm_database_t *database = NULL; if (_filename == NULL) return NULL; filename = resolve_path(_filename, base); if (filename == NULL) return NULL; /* We need to strdup() the filename since dirname() will modify it. */ copy = strdup(filename); if (copy == NULL) goto done_from_file; new_base = dirname(copy); if (new_base == NULL) goto done_from_file; content = file_get_contents(filename); if (content == NULL) goto done_from_file; database = __xcb_xrm_database_from_string(content, new_base, depth); done_from_file: FREE(filename); FREE(copy); FREE(content); return database; } /* * Returns a string representation of a database. * The string is owned by the caller and must be free'd. * * @param database The database to return in string format. * @returns A string representation of the specified database. */ char *xcb_xrm_database_to_string(xcb_xrm_database_t *database) { char *result = NULL; xcb_xrm_entry_t *entry; if (database == NULL) return NULL; TAILQ_FOREACH(entry, database, entries) { char *entry_str = __xcb_xrm_entry_to_string(entry); char *tmp; if (asprintf(&tmp, "%s%s\n", result == NULL ? "" : result, entry_str) < 0) { FREE(entry_str); FREE(result); return NULL; } FREE(entry_str); FREE(result); result = tmp; } return result; } /* * Combines two databases. * The entries from the source database are stored in the target database. If * the same specifier already exists in the target database, the value will be * overridden if override is set; otherwise, the value is discarded. * If NULL is passed for target_db, a new and empty database will be created * and returned in the pointer. * * @param source_db Source database. * @param target_db Target database. * @param override If true, entries from the source database override entries * in the target database using the same resource specifier. */ void xcb_xrm_database_combine(xcb_xrm_database_t *source_db, xcb_xrm_database_t **target_db, bool override) { xcb_xrm_entry_t *entry; if (*target_db == NULL) *target_db = xcb_xrm_database_from_string(""); if (source_db == NULL) return; if (source_db == *target_db) return; TAILQ_FOREACH(entry, source_db, entries) { xcb_xrm_entry_t *copy = __xcb_xrm_entry_copy(entry); __xcb_xrm_database_put(*target_db, copy, override); } } /* * Inserts a new resource into the database. * If the resource already exists, the current value will be replaced. * If NULL is passed for database, a new and empty database will be created and * returned in the pointer. * * Note that this is not the equivalent of @ref * xcb_xrm_database_put_resource_line when concatenating the resource name and * value with a colon. For example, if the value starts with a leading space, * this must (and will) be replaced with the special '\ ' sequence. * * @param database The database to modify. * @param resource The fully qualified or partial resource specifier. * @param value The value of the resource. */ void xcb_xrm_database_put_resource(xcb_xrm_database_t **database, const char *resource, const char *value) { char *escaped; char *line; assert(resource != NULL); assert(value != NULL); if (*database == NULL) *database = xcb_xrm_database_from_string(""); escaped = __xcb_xrm_entry_escape_value(value); if (escaped == NULL) return; if (asprintf(&line, "%s: %s", resource, escaped) < 0) { FREE(escaped); return; } FREE(escaped); xcb_xrm_database_put_resource_line(database, line); FREE(line); } /* * Inserts a new resource into the database. * If the resource already exists, the current value will be replaced. * If NULL is passed for database, a new and empty database will be created and * returned in the pointer. * * @param database The database to modify. * @param line The complete resource specification to insert. */ void xcb_xrm_database_put_resource_line(xcb_xrm_database_t **database, const char *line) { xcb_xrm_entry_t *entry; assert(line != NULL); if (*database == NULL) *database = xcb_xrm_database_from_string(""); /* Ignore comments and directives. The specification guarantees that no * whitespace is allowed before these characters. */ if (line[0] == '!' || line[0] == '#') return; if (xcb_xrm_entry_parse(line, &entry, false) == 0) { __xcb_xrm_database_put(*database, entry, true); } } /** * Destroys the given database. * * @param database The database to destroy. * * @ingroup xcb_xrm_database_t */ void xcb_xrm_database_free(xcb_xrm_database_t *database) { if (database == NULL) return; while (!TAILQ_EMPTY(database)) { xcb_xrm_entry_t *entry = TAILQ_FIRST(database); TAILQ_REMOVE(database, entry, entries); xcb_xrm_entry_free(entry); } FREE(database); } static void __xcb_xrm_database_put(xcb_xrm_database_t *database, xcb_xrm_entry_t *entry, bool override) { xcb_xrm_entry_t *current; if (database == NULL || entry == NULL) return; /* Let's see whether this is a duplicate entry. */ current = TAILQ_FIRST(database); while (current != NULL) { xcb_xrm_entry_t *previous = TAILQ_PREV(current, xcb_xrm_database_t, entries); if (__xcb_xrm_entry_compare(entry, current) == 0) { if (!override) { xcb_xrm_entry_free(entry); return; } TAILQ_REMOVE(database, current, entries); xcb_xrm_entry_free(current); current = previous; if (current == NULL) current = TAILQ_FIRST(database); } if (current == NULL) break; current = TAILQ_NEXT(current, entries); } TAILQ_INSERT_TAIL(database, entry, entries); }