lib/util.h

   1 /** \file lib/util.h
   2  *  \brief Header: various utilities
   3  */
   4
   5 #ifndef MC_UTIL_H
   6 #define MC_UTIL_H
   7
   8 #include <sys/types.h>
   9 #include <sys/stat.h>
  10 #include <inttypes.h>           /* uintmax_t */
  11 #include <unistd.h>
  12
  13 #include "lib/global.h"         /* include <glib.h> */
  14
  15 #include "lib/vfs/vfs.h"
  16
  17 /*** typedefs(not structures) and defined constants **********************************************/
  18
  19 #ifndef MAXSYMLINKS
  20 #define MAXSYMLINKS 32
  21 #endif
  22
  23 #define MAX_SAVED_BOOKMARKS 10
  24
  25 #define MC_PTR_FREE(ptr) do { g_free (ptr); (ptr) = NULL; } while (0)
  26
  27 #define mc_return_if_error(mcerror) do { if (mcerror != NULL && *mcerror != NULL) return; } while (0)
  28 #define mc_return_val_if_error(mcerror, mcvalue) do { if (mcerror != NULL && *mcerror != NULL) return mcvalue; } while (0)
  29
  30 #define whitespace(c) ((c) == ' ' || (c) == '\t')
  31 #define whiteness(c) (whitespace (c) || (c) == '\n')
  32
  33 #define MC_PIPE_BUFSIZE BUF_8K
  34 #define MC_PIPE_STREAM_EOF 0
  35 #define MC_PIPE_STREAM_UNREAD -1
  36 #define MC_PIPE_ERROR_CREATE_PIPE -2
  37 #define MC_PIPE_ERROR_PARSE_COMMAND -3
  38 #define MC_PIPE_ERROR_CREATE_PIPE_STREAM -4
  39 #define MC_PIPE_ERROR_READ -5
  40
  41 /* gnulib efa15594e17fc20827dba66414fb391e99905394
  42
  43  *_GL_CMP (n1, n2) performs a three-valued comparison on n1 vs. n2.
  44  *  It returns
  45  *    1  if n1 > n2
  46  *    0  if n1 == n2
  47  *    -1 if n1 < n2
  48  *  The native code   (n1 > n2 ? 1 : n1 < n2 ? -1 : 0)  produces a conditional
  49  *  jump with nearly all GCC versions up to GCC 10.
  50  *  This variant      (n1 < n2 ? -1 : n1 > n2)  produces a conditional with many
  51  *  GCC versions up to GCC 9.
  52  *  The better code  (n1 > n2) - (n1 < n2)  from Hacker's Delight para 2-9
  53  *  avoids conditional jumps in all GCC versions >= 3.4.
  54  */
  55 #define _GL_CMP(n1, n2) (((n1) > (n2)) - ((n1) < (n2)))
  56
  57 /* Difference or zero */
  58 #define DOZ(a, b) ((a) > (b) ? (a) - (b) : 0)
  59
  60 /* flags for shell_execute */
  61 #define EXECUTE_INTERNAL (1 << 0)
  62 #define EXECUTE_AS_SHELL (1 << 2)
  63 #define EXECUTE_HIDE     (1 << 3)
  64
  65 /*** enums ***************************************************************************************/
  66
  67 /* Pathname canonicalization */
  68 /* *INDENT-OFF* */
  69 typedef enum
  70 {
  71     CANON_PATH_NOCHANGE = 0,
  72     CANON_PATH_JOINSLASHES = 1L << 0,   /**< Multiple '/'s are collapsed to a single '/' */
  73     CANON_PATH_REMSLASHDOTS = 1L << 1,  /**< Leading './'s, '/'s and trailing '/.'s are removed */
  74     CANON_PATH_REMDOUBLEDOTS = 1L << 3, /**< Non-leading '../'s and trailing '..'s are handled by removing
  75                                              portions of the path */
  76     CANON_PATH_GUARDUNC = 1L << 4,      /**< Detect and preserve UNC paths: //server/... */
  77     CANON_PATH_ALL = CANON_PATH_JOINSLASHES | CANON_PATH_REMSLASHDOTS
  78                    | CANON_PATH_REMDOUBLEDOTS | CANON_PATH_GUARDUNC  /**< All flags */
  79 } canon_path_flags_t;
  80 /* *INDENT-ON* */
  81
  82 enum compression_type
  83 {
  84     COMPRESSION_NONE,
  85     COMPRESSION_ZIP,
  86     COMPRESSION_GZIP,
  87     COMPRESSION_BZIP,
  88     COMPRESSION_BZIP2,
  89     COMPRESSION_LZIP,
  90     COMPRESSION_LZ4,
  91     COMPRESSION_LZMA,
  92     COMPRESSION_LZO,
  93     COMPRESSION_XZ,
  94     COMPRESSION_ZSTD,
  95 };
  96
  97 /* stdout or stderr stream of child process */
  98 typedef struct
  99 {
 100     /* file descriptor */
 101     int fd;
 102     /* data read from fd */
 103     char buf[MC_PIPE_BUFSIZE];
 104     /* current position in @buf (used by mc_pstream_get_string()) */
 105     size_t pos;
 106     /* positive: length of data in buf;
 107      * MC_PIPE_STREAM_EOF: EOF of fd;
 108      * MC_PIPE_STREAM_UNREAD: there was not read from fd;
 109      * MC_PIPE_ERROR_READ: reading error from fd.
 110      */
 111     ssize_t len;
 112     /* whether buf is null-terminated or not */
 113     gboolean null_term;
 114     /* error code in case of len == MC_PIPE_ERROR_READ */
 115     int error;
 116 } mc_pipe_stream_t;
 117
 118 /* Pipe descriptor for child process */
 119 typedef struct
 120 {
 121     /* PID of child process */
 122     GPid child_pid;
 123     /* stdout of child process */
 124     mc_pipe_stream_t out;
 125     /* stderr of child process */
 126     mc_pipe_stream_t err;
 127 } mc_pipe_t;
 128
 129 /* sighandler_t is GNU extension */
 130 #ifndef HAVE_SIGHANDLER_T
 131 typedef void (*sighandler_t) (int);
 132 #endif
 133
 134 /*** structures declarations (and typedefs of structures)*****************************************/
 135
 136 /*** global variables defined in .c file *********************************************************/
 137
 138 extern struct sigaction startup_handler;
 139
 140 /*** declarations of public functions ************************************************************/
 141
 142 int is_printable (int c);
 143
 144 /* Quote the filename for the purpose of inserting it into the command
 145  * line.  If quote_percent is 1, replace "%" with "%%" - the percent is
 146  * processed by the mc command line. */
 147 char *name_quote (const char *c, gboolean quote_percent);
 148
 149 /* returns a duplicate of c. */
 150 char *fake_name_quote (const char *c, gboolean quote_percent);
 151
 152 /* path_trunc() is the same as str_trunc() but
 153  * it deletes possible password from path for security
 154  * reasons. */
 155 const char *path_trunc (const char *path, size_t trunc_len);
 156
 157 /* return a static string representing size, appending "K" or "M" for
 158  * big sizes.
 159  * NOTE: uses the same static buffer as size_trunc_sep. */
 160 const char *size_trunc (uintmax_t size, gboolean use_si);
 161
 162 /* return a static string representing size, appending "K" or "M" for
 163  * big sizes. Separates every three digits by ",".
 164  * NOTE: uses the same static buffer as size_trunc. */
 165 const char *size_trunc_sep (uintmax_t size, gboolean use_si);
 166
 167 /* Print file SIZE to BUFFER, but don't exceed LEN characters,
 168  * not including trailing 0. BUFFER should be at least LEN+1 long.
 169  *
 170  * Units: size units (0=bytes, 1=Kbytes, 2=Mbytes, etc.) */
 171 void size_trunc_len (char *buffer, unsigned int len, uintmax_t size, int units, gboolean use_si);
 172 const char *string_perm (mode_t mode_bits);
 173
 174 const char *extension (const char *);
 175 const char *unix_error_string (int error_num);
 176 const char *skip_separators (const char *s);
 177 const char *skip_numbers (const char *s);
 178 char *strip_ctrl_codes (char *s);
 179
 180 /* Replaces "\\E" and "\\e" with "\033". Replaces "^" + [a-z] with
 181  * ((char) 1 + (c - 'a')). The same goes for "^" + [A-Z].
 182  * Returns a newly allocated string. */
 183 char *convert_controls (const char *s);
 184
 185 /* overwrites passwd with '\0's and frees it. */
 186 void wipe_password (char *passwd);
 187
 188 char *diff_two_paths (const vfs_path_t * vpath1, const vfs_path_t * vpath2);
 189
 190 /* Returns the basename of fname. The result is a pointer into fname. */
 191 const char *x_basename (const char *fname);
 192
 193 char *load_mc_home_file (const char *from, const char *filename, char **allocated_filename,
 194                          size_t *length);
 195
 196 /* uid/gid managing */
 197 void init_groups (void);
 198 void destroy_groups (void);
 199 int get_user_permissions (struct stat *buf);
 200
 201 void init_uid_gid_cache (void);
 202 const char *get_group (gid_t gid);
 203 const char *get_owner (uid_t uid);
 204
 205 /* Returns a copy of *s until a \n is found and is below top */
 206 const char *extract_line (const char *s, const char *top, size_t *len);
 207
 208 /* System call wrappers */
 209 MC_MOCKABLE sighandler_t my_signal (int signum, sighandler_t handler);
 210 MC_MOCKABLE int my_sigaction (int signum, const struct sigaction *act, struct sigaction *oldact);
 211 MC_MOCKABLE pid_t my_fork (void);
 212 MC_MOCKABLE int my_execvp (const char *file, char *const argv[]);
 213 MC_MOCKABLE char *my_get_current_dir (void);
 214
 215 /* Process spawning */
 216 int my_system (int flags, const char *shell, const char *command);
 217 int my_systeml (int flags, const char *shell, ...);
 218 int my_systemv (const char *command, char *const argv[]);
 219 int my_systemv_flags (int flags, const char *command, char *const argv[]);
 220
 221 mc_pipe_t *mc_popen (const char *command, gboolean read_out, gboolean read_err, GError ** error);
 222 void mc_pread (mc_pipe_t * p, GError ** error);
 223 void mc_pclose (mc_pipe_t * p, GError ** error);
 224
 225 GString *mc_pstream_get_string (mc_pipe_stream_t * ps);
 226
 227 MC_MOCKABLE void my_exit (int status);
 228 void save_stop_handler (void);
 229
 230 /* Tilde expansion */
 231 char *tilde_expand (const char *directory);
 232
 233 void canonicalize_pathname_custom (char *path, canon_path_flags_t flags);
 234
 235 char *mc_realpath (const char *path, char *resolved_path);
 236
 237 /* Looks for "magic" bytes at the start of the VFS file to guess the
 238  * compression type. Side effect: modifies the file position. */
 239 enum compression_type get_compression_type (int fd, const char *name);
 240 const char *decompress_extension (int type);
 241
 242 GList *list_append_unique (GList * list, char *text);
 243
 244 /* Position saving and restoring */
 245 /* Load position for the given filename */
 246 void load_file_position (const vfs_path_t * filename_vpath, long *line, long *column,
 247                          off_t * offset, GArray ** bookmarks);
 248 /* Save position for the given filename */
 249 void save_file_position (const vfs_path_t * filename_vpath, long line, long column, off_t offset,
 250                          GArray * bookmarks);
 251
 252
 253 /* if ch is in [A-Za-z], returns the corresponding control character,
 254  * else returns the argument. */
 255 extern int ascii_alpha_to_cntrl (int ch);
 256
 257 #undef Q_
 258 const char *Q_ (const char *s);
 259
 260 gboolean mc_util_make_backup_if_possible (const char *file_name, const char *backup_suffix);
 261 gboolean mc_util_restore_from_backup_if_possible (const char *file_name, const char *backup_suffix);
 262 gboolean mc_util_unlink_backup_if_possible (const char *file_name, const char *backup_suffix);
 263
 264 MC_MOCKABLE char *guess_message_value (void);
 265
 266 char *mc_build_filename (const char *first_element, ...);
 267 char *mc_build_filenamev (const char *first_element, va_list args);
 268
 269 const char *mc_get_profile_root (void);
 270
 271 /* *INDENT-OFF* */
 272 void mc_propagate_error (GError ** dest, int code, const char *format, ...) G_GNUC_PRINTF (3, 4);
 273 void mc_replace_error (GError ** dest, int code, const char *format, ...) G_GNUC_PRINTF (3, 4);
 274 /* *INDENT-ON* */
 275
 276 gboolean mc_time_elapsed (gint64 * timestamp, gint64 delay);
 277
 278 /* --------------------------------------------------------------------------------------------- */
 279 /*** inline functions ****************************************************************************/
 280 /* --------------------------------------------------------------------------------------------- */
 281
 282 static inline gboolean
 283 exist_file (const char *name)
 284 {
 285     return (access (name, R_OK) == 0);
 286 }
 287
 288 /* --------------------------------------------------------------------------------------------- */
 289
 290 static inline gboolean
 291 is_exe (mode_t mode)
 292 {
 293     return ((mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0);
 294 }
 295
 296 /* --------------------------------------------------------------------------------------------- */
 297 /**
 298  * Canonicalize path with CANON_PATH_ALL.
 299  *
 300  * @param path path to file
 301  * @param flags canonicalization flags
 302  *
 303  * All modifications of @path are made in place.
 304  * Well formed UNC paths are modified only in the local part.
 305  */
 306
 307 static inline void
 308 canonicalize_pathname (char *path)
 309 {
 310     canonicalize_pathname_custom (path, CANON_PATH_ALL);
 311 }
 312
 313 /* --------------------------------------------------------------------------------------------- */
 314
 315 #endif /* MC_UTIL_H */