/* * utils.c: utilities * * Copyright (c) 2014, Přemysl Janouch * All rights reserved. * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * 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. * */ #define _POSIX_C_SOURCE 199309L #define _XOPEN_SOURCE 600 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "siphash.h" #if defined __GNUC__ #define ATTRIBUTE_PRINTF(x, y) __attribute__ ((format (printf, x, y))) #else // ! __GNUC__ #define ATTRIBUTE_PRINTF(x, y) #endif // ! __GNUC__ #if defined __GNUC__ && __GNUC__ >= 4 #define ATTRIBUTE_SENTINEL __attribute__ ((sentinel)) #else // ! __GNUC__ || __GNUC__ < 4 #define ATTRIBUTE_SENTINEL #endif // ! __GNUC__ || __GNUC__ < 4 #define N_ELEMENTS(a) (sizeof (a) / sizeof ((a)[0])) #define BLOCK_START do { #define BLOCK_END } while (0) // --- Logging ----------------------------------------------------------------- static void log_message_stdio (void *user_data, const char *quote, const char *fmt, va_list ap) { (void) user_data; FILE *stream = stderr; fputs (quote, stream); vfprintf (stream, fmt, ap); fputs ("\n", stream); } static void (*g_log_message_real) (void *, const char *, const char *, va_list) = log_message_stdio; static void log_message (void *user_data, const char *quote, const char *fmt, ...) ATTRIBUTE_PRINTF (3, 4); static void log_message (void *user_data, const char *quote, const char *fmt, ...) { va_list ap; va_start (ap, fmt); g_log_message_real (user_data, quote, fmt, ap); va_end (ap); } // `fatal' is reserved for unexpected failures that would harm further operation #ifndef print_fatal_data #define print_fatal_data NULL #endif #ifndef print_error_data #define print_error_data NULL #endif #ifndef print_warning_data #define print_warning_data NULL #endif #ifndef print_status_data #define print_status_data NULL #endif #define print_fatal(...) \ log_message (print_fatal_data, "fatal: ", __VA_ARGS__) #define print_error(...) \ log_message (print_error_data, "error: ", __VA_ARGS__) #define print_warning(...) \ log_message (print_warning_data, "warning: ", __VA_ARGS__) #define print_status(...) \ log_message (print_status_data, "-- ", __VA_ARGS__) #define exit_fatal(...) \ BLOCK_START \ print_fatal (__VA_ARGS__); \ exit (EXIT_FAILURE); \ BLOCK_END // --- Debugging and assertions ------------------------------------------------ // We should check everything that may possibly fail with at least a soft // assertion, so that any causes for problems don't slip us by silently. // // `g_soft_asserts_are_deadly' may be useful while running inside a debugger. static bool g_debug_mode; ///< Debug messages are printed static bool g_soft_asserts_are_deadly; ///< soft_assert() aborts as well #define print_debug(...) \ BLOCK_START \ if (g_debug_mode) \ log_message ("debug: ", __VA_ARGS__); \ BLOCK_END static void assertion_failure_handler (bool is_fatal, const char *file, int line, const char *function, const char *condition) { if (is_fatal) { print_fatal ("assertion failed [%s:%d in function %s]: %s", file, line, function, condition); abort (); } else print_debug ("assertion failed [%s:%d in function %s]: %s", file, line, function, condition); } #define soft_assert(condition) \ ((condition) ? true : \ (assertion_failure_handler (g_soft_asserts_are_deadly, \ __FILE__, __LINE__, __func__, #condition), false)) #define hard_assert(condition) \ ((condition) ? (void) 0 : \ assertion_failure_handler (true, \ __FILE__, __LINE__, __func__, #condition)) // --- Safe memory management -------------------------------------------------- // When a memory allocation fails and we need the memory, we're usually pretty // much fucked. Use the non-prefixed versions when there's a legitimate // worry that an unrealistic amount of memory may be requested for allocation. // XXX: it's not a good idea to use print_message() as it may want to allocate // further memory for printf() and the output streams. That may fail. static void * xmalloc (size_t n) { void *p = malloc (n); if (!p) exit_fatal ("malloc: %s", strerror (errno)); return p; } static void * xcalloc (size_t n, size_t m) { void *p = calloc (n, m); if (!p && n && m) exit_fatal ("calloc: %s", strerror (errno)); return p; } static void * xrealloc (void *o, size_t n) { void *p = realloc (o, n); if (!p && n) exit_fatal ("realloc: %s", strerror (errno)); return p; } static void * xreallocarray (void *o, size_t n, size_t m) { if (m && n > SIZE_MAX / m) { errno = ENOMEM; exit_fatal ("reallocarray: %s", strerror (errno)); } return xrealloc (o, n * m); } static char * xstrdup (const char *s) { return strcpy (xmalloc (strlen (s) + 1), s); } static char * xstrndup (const char *s, size_t n) { size_t size = strlen (s); if (n > size) n = size; char *copy = xmalloc (n + 1); memcpy (copy, s, n); copy[n] = '\0'; return copy; } // --- Double-linked list helpers ---------------------------------------------- #define LIST_HEADER(type) \ struct type *next; \ struct type *prev; #define LIST_PREPEND(head, link) \ BLOCK_START \ (link)->prev = NULL; \ (link)->next = (head); \ if ((link)->next) \ (link)->next->prev = (link); \ (head) = (link); \ BLOCK_END #define LIST_UNLINK(head, link) \ BLOCK_START \ if ((link)->prev) \ (link)->prev->next = (link)->next; \ else \ (head) = (link)->next; \ if ((link)->next) \ (link)->next->prev = (link)->prev; \ BLOCK_END #define LIST_APPEND_WITH_TAIL(head, tail, link) \ BLOCK_START \ (link)->prev = (tail); \ (link)->next = NULL; \ if ((link)->prev) \ (link)->prev->next = (link); \ else \ (head) = (link); \ (tail) = (link); \ BLOCK_END #define LIST_UNLINK_WITH_TAIL(head, tail, link) \ BLOCK_START \ if ((tail) == (link)) \ (tail) = (link)->prev; \ LIST_UNLINK ((head), (link)); \ BLOCK_END // --- Dynamically allocated string array -------------------------------------- struct str_vector { char **vector; size_t len; size_t alloc; }; static void str_vector_init (struct str_vector *self) { self->alloc = 4; self->len = 0; self->vector = xcalloc (sizeof *self->vector, self->alloc); } static void str_vector_free (struct str_vector *self) { unsigned i; for (i = 0; i < self->len; i++) free (self->vector[i]); free (self->vector); self->vector = NULL; } static void str_vector_add_owned (struct str_vector *self, char *s) { self->vector[self->len] = s; if (++self->len >= self->alloc) self->vector = xreallocarray (self->vector, sizeof *self->vector, (self->alloc <<= 1)); self->vector[self->len] = NULL; } static void str_vector_add (struct str_vector *self, const char *s) { str_vector_add_owned (self, xstrdup (s)); } // --- Dynamically allocated strings ------------------------------------------- // Basically a string builder to abstract away manual memory management. struct str { char *str; ///< String data, null terminated size_t alloc; ///< How many bytes are allocated size_t len; ///< How long the string actually is }; static void str_init (struct str *self) { self->alloc = 16; self->len = 0; self->str = strcpy (xmalloc (self->alloc), ""); } static void str_free (struct str *self) { free (self->str); self->str = NULL; self->alloc = 0; self->len = 0; } static void str_reset (struct str *self) { str_free (self); str_init (self); } static char * str_steal (struct str *self) { char *str = self->str; self->str = NULL; str_free (self); return str; } static void str_ensure_space (struct str *self, size_t n) { // We allocate at least one more byte for the terminating null character size_t new_alloc = self->alloc; while (new_alloc <= self->len + n) new_alloc <<= 1; if (new_alloc != self->alloc) self->str = xrealloc (self->str, (self->alloc = new_alloc)); } static void str_append_data (struct str *self, const void *data, size_t n) { str_ensure_space (self, n); memcpy (self->str + self->len, data, n); self->len += n; self->str[self->len] = '\0'; } static void str_append_c (struct str *self, char c) { str_append_data (self, &c, 1); } static void str_append (struct str *self, const char *s) { str_append_data (self, s, strlen (s)); } static void str_append_str (struct str *self, const struct str *another) { str_append_data (self, another->str, another->len); } static int str_append_vprintf (struct str *self, const char *fmt, va_list va) { va_list ap; int size; va_copy (ap, va); size = vsnprintf (NULL, 0, fmt, ap); va_end (ap); if (size < 0) return -1; va_copy (ap, va); str_ensure_space (self, size); size = vsnprintf (self->str + self->len, self->alloc - self->len, fmt, ap); va_end (ap); if (size > 0) self->len += size; return size; } static int str_append_printf (struct str *self, const char *fmt, ...) ATTRIBUTE_PRINTF (2, 3); static int str_append_printf (struct str *self, const char *fmt, ...) { va_list ap; va_start (ap, fmt); int size = str_append_vprintf (self, fmt, ap); va_end (ap); return size; } // --- Errors ------------------------------------------------------------------ // Error reporting utilities. Inspired by GError, only much simpler. struct error { char *message; ///< Textual description of the event }; static void error_set (struct error **e, const char *message, ...) ATTRIBUTE_PRINTF (2, 3); static void error_set (struct error **e, const char *message, ...) { if (!e) return; va_list ap; va_start (ap, message); int size = vsnprintf (NULL, 0, message, ap); va_end (ap); hard_assert (size >= 0); struct error *tmp = xmalloc (sizeof *tmp); tmp->message = xmalloc (size + 1); va_start (ap, message); size = vsnprintf (tmp->message, size + 1, message, ap); va_end (ap); hard_assert (size >= 0); soft_assert (*e == NULL); *e = tmp; } static void error_free (struct error *e) { free (e->message); free (e); } // --- String hash map --------------------------------------------------------- // The most basic map (or associative array). struct str_map_link { LIST_HEADER (str_map_link) void *data; ///< Payload size_t key_length; ///< Length of the key without '\0' char key[]; ///< The key for this link }; struct str_map { struct str_map_link **map; ///< The hash table data itself size_t alloc; ///< Number of allocated entries size_t len; ///< Number of entries in the table void (*free) (void *); ///< Callback to destruct the payload /// Callback that transforms all key values for storage and comparison; /// has to behave exactly like strxfrm(). size_t (*key_xfrm) (char *dest, const char *src, size_t n); }; // As long as you don't remove the current entry, you can modify the map. // Use `link' directly to access the data. struct str_map_iter { struct str_map *map; ///< The map we're iterating size_t next_index; ///< Next table index to search struct str_map_link *link; ///< Current link }; #define STR_MAP_MIN_ALLOC 16 typedef void (*str_map_free_fn) (void *); static void str_map_init (struct str_map *self) { self->alloc = STR_MAP_MIN_ALLOC; self->len = 0; self->free = NULL; self->key_xfrm = NULL; self->map = xcalloc (self->alloc, sizeof *self->map); } static void str_map_free (struct str_map *self) { struct str_map_link **iter, **end = self->map + self->alloc; struct str_map_link *link, *tmp; for (iter = self->map; iter < end; iter++) for (link = *iter; link; link = tmp) { tmp = link->next; if (self->free) self->free (link->data); free (link); } free (self->map); self->map = NULL; } static void str_map_iter_init (struct str_map_iter *self, struct str_map *map) { self->map = map; self->next_index = 0; self->link = NULL; } static void * str_map_iter_next (struct str_map_iter *self) { struct str_map *map = self->map; if (self->link) self->link = self->link->next; while (!self->link) { if (self->next_index >= map->alloc) return NULL; self->link = map->map[self->next_index++]; } return self->link->data; } static uint64_t str_map_hash (const char *s, size_t len) { static unsigned char key[16] = "SipHash 2-4 key!"; return siphash (key, (const void *) s, len); } static uint64_t str_map_pos (struct str_map *self, const char *s) { size_t mask = self->alloc - 1; return str_map_hash (s, strlen (s)) & mask; } static uint64_t str_map_link_hash (struct str_map_link *self) { return str_map_hash (self->key, self->key_length); } static void str_map_resize (struct str_map *self, size_t new_size) { struct str_map_link **old_map = self->map; size_t i, old_size = self->alloc; // Only powers of two, so that we don't need to compute the modulo hard_assert ((new_size & (new_size - 1)) == 0); size_t mask = new_size - 1; self->alloc = new_size; self->map = xcalloc (self->alloc, sizeof *self->map); for (i = 0; i < old_size; i++) { struct str_map_link *iter = old_map[i], *next_iter; while (iter) { next_iter = iter->next; uint64_t pos = str_map_link_hash (iter) & mask; LIST_PREPEND (self->map[pos], iter); iter = next_iter; } } free (old_map); } static void str_map_set_real (struct str_map *self, const char *key, void *value) { uint64_t pos = str_map_pos (self, key); struct str_map_link *iter = self->map[pos]; for (; iter; iter = iter->next) { if (strcmp (key, iter->key)) continue; // Storing the same data doesn't destroy it if (self->free && value != iter->data) self->free (iter->data); if (value) { iter->data = value; return; } LIST_UNLINK (self->map[pos], iter); free (iter); self->len--; // The array should be at least 1/4 full if (self->alloc >= (STR_MAP_MIN_ALLOC << 2) && self->len < (self->alloc >> 2)) str_map_resize (self, self->alloc >> 2); return; } if (!value) return; if (self->len >= self->alloc) { str_map_resize (self, self->alloc << 1); pos = str_map_pos (self, key); } // Link in a new element for the given pair size_t key_length = strlen (key); struct str_map_link *link = xmalloc (sizeof *link + key_length + 1); link->data = value; link->key_length = key_length; memcpy (link->key, key, key_length + 1); LIST_PREPEND (self->map[pos], link); self->len++; } static void str_map_set (struct str_map *self, const char *key, void *value) { if (!self->key_xfrm) { str_map_set_real (self, key, value); return; } char tmp[self->key_xfrm (NULL, key, 0) + 1]; self->key_xfrm (tmp, key, sizeof tmp); str_map_set_real (self, tmp, value); } static void * str_map_find_real (struct str_map *self, const char *key) { struct str_map_link *iter = self->map[str_map_pos (self, key)]; for (; iter; iter = iter->next) if (!strcmp (key, (const char *) iter + sizeof *iter)) return iter->data; return NULL; } static void * str_map_find (struct str_map *self, const char *key) { if (!self->key_xfrm) return str_map_find_real (self, key); char tmp[self->key_xfrm (NULL, key, 0) + 1]; self->key_xfrm (tmp, key, sizeof tmp); return str_map_find_real (self, tmp); } // --- Utilities --------------------------------------------------------------- static void split_str_ignore_empty (const char *s, char delimiter, struct str_vector *out) { const char *begin = s, *end; while ((end = strchr (begin, delimiter))) { if (begin != end) str_vector_add_owned (out, xstrndup (begin, end - begin)); begin = ++end; } if (*begin) str_vector_add (out, begin); } static char *xstrdup_printf (const char *format, ...) ATTRIBUTE_PRINTF (1, 2); static char * xstrdup_printf (const char *format, ...) { va_list ap; va_start (ap, format); int size = vsnprintf (NULL, 0, format, ap); va_end (ap); if (size < 0) return NULL; char buf[size + 1]; va_start (ap, format); size = vsnprintf (buf, sizeof buf, format, ap); va_end (ap); if (size < 0) return NULL; return xstrdup (buf); } static char * iconv_xstrdup (iconv_t conv, char *in, size_t in_len, size_t *out_len) { char *buf, *buf_ptr; size_t out_left, buf_alloc; buf = buf_ptr = xmalloc (out_left = buf_alloc = 64); char *in_ptr = in; if (in_len == (size_t) -1) in_len = strlen (in) + 1; while (iconv (conv, (char **) &in_ptr, &in_len, (char **) &buf_ptr, &out_left) == (size_t) -1) { if (errno != E2BIG) { free (buf); return NULL; } out_left += buf_alloc; char *new_buf = xrealloc (buf, buf_alloc <<= 1); buf_ptr += new_buf - buf; buf = new_buf; } if (out_len) *out_len = buf_alloc - out_left; return buf; } static bool str_append_env_path (struct str *output, const char *var, bool only_absolute) { const char *value = getenv (var); if (!value || (only_absolute && *value != '/')) return false; str_append (output, value); return true; } static void get_xdg_home_dir (struct str *output, const char *var, const char *def) { str_reset (output); if (!str_append_env_path (output, var, true)) { str_append_env_path (output, "HOME", false); str_append_c (output, '/'); str_append (output, def); } } static void get_xdg_config_dirs (struct str_vector *out) { struct str config_home; str_init (&config_home); get_xdg_home_dir (&config_home, "XDG_CONFIG_HOME", ".config"); str_vector_add (out, config_home.str); str_free (&config_home); const char *xdg_config_dirs; if ((xdg_config_dirs = getenv ("XDG_CONFIG_DIRS"))) split_str_ignore_empty (xdg_config_dirs, ':', out); } static char * resolve_config_filename (const char *filename) { // Absolute path is absolute if (*filename == '/') return xstrdup (filename); struct str_vector paths; str_vector_init (&paths); get_xdg_config_dirs (&paths); struct str file; str_init (&file); char *result = NULL; for (unsigned i = 0; i < paths.len; i++) { // As per spec, relative paths are ignored if (*paths.vector[i] != '/') continue; str_reset (&file); str_append_printf (&file, "%s/" PROGRAM_NAME "/%s", paths.vector[i], filename); struct stat st; if (!stat (file.str, &st)) { result = str_steal (&file); break; } } str_vector_free (&paths); str_free (&file); return result; } static bool ensure_directory_existence (const char *path, struct error **e) { struct stat st; if (stat (path, &st)) { if (mkdir (path, S_IRWXU | S_IRWXG | S_IRWXO)) { error_set (e, "cannot create directory `%s': %s", path, strerror (errno)); return false; } } else if (!S_ISDIR (st.st_mode)) { error_set (e, "cannot create directory `%s': %s", path, "file exists but is not a directory"); return false; } return true; } static bool mkdir_with_parents (char *path, struct error **e) { char *p = path; // XXX: This is prone to the TOCTTOU problem. The solution would be to // rewrite the function using the {mkdir,fstat}at() functions from // POSIX.1-2008, ideally returning a file descriptor to the open // directory, with the current code as a fallback. Or to use chdir(). while ((p = strchr (p + 1, '/'))) { *p = '\0'; bool success = ensure_directory_existence (path, e); *p = '/'; if (!success) return false; } return ensure_directory_existence (path, e); } static bool read_line (FILE *fp, struct str *s) { int c; bool at_end = true; str_reset (s); while ((c = fgetc (fp)) != EOF) { at_end = false; if (c == '\r') continue; if (c == '\n') break; str_append_c (s, c); } return !at_end; } // --- Configuration ----------------------------------------------------------- // The keys are stripped of surrounding whitespace, the values are not. struct config_item { const char *key; const char *default_value; const char *description; }; static bool read_config_file (struct str_map *config, struct error **e) { char *filename = resolve_config_filename (PROGRAM_NAME ".conf"); if (!filename) return true; FILE *fp = fopen (filename, "r"); if (!fp) { error_set (e, "could not open `%s' for reading: %s", filename, strerror (errno)); free (filename); return false; } struct str line; str_init (&line); bool errors = false; for (unsigned line_no = 1; read_line (fp, &line); line_no++) { char *start = line.str; if (*start == '#') continue; while (isspace (*start)) start++; char *end = strchr (start, '='); if (end) { char *value = end + 1; do *end = '\0'; while (isspace (*--end)); str_map_set (config, start, xstrdup (value)); } else if (*start) { error_set (e, "line %u in config: %s", line_no, "malformed input"); errors = true; break; } } str_free (&line); fclose (fp); free (filename); return !errors; } static char * write_default_config (const char *filename, const char *prolog, const struct config_item *table, struct error **e) { struct str path, base; str_init (&path); str_init (&base); if (filename) { char *tmp = xstrdup (filename); str_append (&path, dirname (tmp)); strcpy (tmp, filename); str_append (&base, basename (tmp)); free (tmp); } else { get_xdg_home_dir (&path, "XDG_CONFIG_HOME", ".config"); str_append (&path, "/" PROGRAM_NAME); str_append (&base, PROGRAM_NAME ".conf"); } if (!mkdir_with_parents (path.str, e)) goto error; str_append_c (&path, '/'); str_append_str (&path, &base); FILE *fp = fopen (path.str, "w"); if (!fp) { error_set (e, "could not open `%s' for writing: %s", path.str, strerror (errno)); goto error; } if (prolog) fputs (prolog, fp); errno = 0; for (; table->key != NULL; table++) { fprintf (fp, "# %s\n", table->description); if (table->default_value) fprintf (fp, "%s=%s\n", table->key, table->default_value); else fprintf (fp, "#%s=\n", table->key); } fclose (fp); if (errno) { error_set (e, "writing to `%s' failed: %s", path.str, strerror (errno)); goto error; } str_free (&base); return str_steal (&path); error: str_free (&base); str_free (&path); return NULL; } static void call_write_default_config (const char *hint, const struct config_item *table) { static const char *prolog = "# " PROGRAM_NAME " " PROGRAM_VERSION " configuration file\n" "#\n" "# Relative paths are searched for in ${XDG_CONFIG_HOME:-~/.config}\n" "# /" PROGRAM_NAME " as well as in $XDG_CONFIG_DIRS/" PROGRAM_NAME "\n" "\n"; struct error *e = NULL; char *filename = write_default_config (hint, prolog, table, &e); if (!filename) { print_error ("%s", e->message); error_free (e); exit (EXIT_FAILURE); } print_status ("configuration written to `%s'", filename); free (filename); } // --- Option handler ---------------------------------------------------------- // Simple wrapper for the getopt_long API to make it easier to use and maintain. #define OPT_USAGE_ALIGNMENT_COLUMN 30 ///< Alignment for option descriptions enum { OPT_OPTIONAL_ARG = (1 << 0), ///< The argument is optional OPT_LONG_ONLY = (1 << 1) ///< Ignore the short name in opt_string }; // All options need to have both a short name, and a long name. The short name // is what is returned from opt_handler_get(). It is possible to define a value // completely out of the character range combined with the OPT_LONG_ONLY flag. // // When `arg_hint' is defined, the option is assumed to have an argument. struct opt { int short_name; ///< The single-letter name const char *long_name; ///< The long name const char *arg_hint; ///< Option argument hint int flags; ///< Option flags const char *description; ///< Option description }; struct opt_handler { int argc; ///< The number of program arguments char **argv; ///< Program arguments const char *arg_hint; ///< Program arguments hint const char *description; ///< Description of the program const struct opt *opts; ///< The list of options size_t opts_len; ///< The length of the option array struct option *options; ///< The list of options for getopt char *opt_string; ///< The `optstring' for getopt }; static void opt_handler_free (struct opt_handler *self) { free (self->options); free (self->opt_string); } static void opt_handler_init (struct opt_handler *self, int argc, char **argv, const struct opt *opts, const char *arg_hint, const char *description) { memset (self, 0, sizeof *self); self->argc = argc; self->argv = argv; self->arg_hint = arg_hint; self->description = description; size_t len = 0; for (const struct opt *iter = opts; iter->long_name; iter++) len++; self->opts = opts; self->opts_len = len; self->options = xcalloc (len + 1, sizeof *self->options); struct str opt_string; str_init (&opt_string); for (size_t i = 0; i < len; i++) { const struct opt *opt = opts + i; struct option *mapped = self->options + i; mapped->name = opt->long_name; if (!opt->arg_hint) mapped->has_arg = no_argument; else if (opt->flags & OPT_OPTIONAL_ARG) mapped->has_arg = optional_argument; else mapped->has_arg = required_argument; mapped->val = opt->short_name; if (opt->flags & OPT_LONG_ONLY) continue; str_append_c (&opt_string, opt->short_name); if (opt->arg_hint) { str_append_c (&opt_string, ':'); if (opt->flags & OPT_OPTIONAL_ARG) str_append_c (&opt_string, ':'); } } self->opt_string = str_steal (&opt_string); } static void opt_handler_usage (struct opt_handler *self, FILE *stream) { struct str usage; str_init (&usage); str_append_printf (&usage, "Usage: %s [OPTION]... %s\n", self->argv[0], self->arg_hint ? self->arg_hint : ""); str_append_printf (&usage, "%s\n\n", self->description); for (size_t i = 0; i < self->opts_len; i++) { struct str row; str_init (&row); const struct opt *opt = self->opts + i; if (!(opt->flags & OPT_LONG_ONLY)) str_append_printf (&row, " -%c, ", opt->short_name); else str_append (&row, " "); str_append_printf (&row, "--%s", opt->long_name); if (opt->arg_hint) str_append_printf (&row, (opt->flags & OPT_OPTIONAL_ARG) ? " [%s]" : " %s", opt->arg_hint); // TODO: keep the indent if there are multiple lines if (row.len + 2 <= OPT_USAGE_ALIGNMENT_COLUMN) { str_append (&row, " "); str_append_printf (&usage, "%-*s%s\n", OPT_USAGE_ALIGNMENT_COLUMN, row.str, opt->description); } else str_append_printf (&usage, "%s\n%-*s%s\n", row.str, OPT_USAGE_ALIGNMENT_COLUMN, "", opt->description); str_free (&row); } fputs (usage.str, stream); str_free (&usage); } static int opt_handler_get (struct opt_handler *self) { return getopt_long (self->argc, self->argv, self->opt_string, self->options, NULL); }