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 /*** enums ***************************************************************************************/
  61
  62 /* Pathname canonicalization */
  63 /* *INDENT-OFF* */
  64 typedef enum
  65 {
  66     CANON_PATH_NOCHANGE = 0,
  67     CANON_PATH_JOINSLASHES = 1L << 0,   /**< Multiple '/'s are collapsed to a single '/' */
  68     CANON_PATH_REMSLASHDOTS = 1L << 1,  /**< Leading './'s, '/'s and trailing '/.'s are removed */
  69     CANON_PATH_REMDOUBLEDOTS = 1L << 3, /**< Non-leading '../'s and trailing '..'s are handled by removing
  70                                              portions of the path */
  71     CANON_PATH_GUARDUNC = 1L << 4,      /**< Detect and preserve UNC paths: //server/... */
  72     CANON_PATH_ALL = CANON_PATH_JOINSLASHES | CANON_PATH_REMSLASHDOTS
  73                    | CANON_PATH_REMDOUBLEDOTS | CANON_PATH_GUARDUNC  /**< All flags */
  74 } canon_path_flags_t;
  75 /* *INDENT-ON* */
  76
  77 enum compression_type
  78 {
  79     COMPRESSION_NONE,
  80     COMPRESSION_ZIP,
  81     COMPRESSION_GZIP,
  82     COMPRESSION_BZIP,
  83     COMPRESSION_BZIP2,
  84     COMPRESSION_LZIP,
  85     COMPRESSION_LZ4,
  86     COMPRESSION_LZMA,
  87     COMPRESSION_LZO,
  88     COMPRESSION_XZ,
  89     COMPRESSION_ZSTD,
  90 };
  91
  92 /* stdout or stderr stream of child process */
  93 typedef struct
  94 {
  95     /* file descriptor */
  96     int fd;
  97     /* data read from fd */
  98     char buf[MC_PIPE_BUFSIZE];
  99     /* current position in @buf (used by mc_pstream_get_string()) */
 100     size_t pos;
 101     /* positive: length of data in buf;
 102      * MC_PIPE_STREAM_EOF: EOF of fd;
 103      * MC_PIPE_STREAM_UNREAD: there was not read from fd;
 104      * MC_PIPE_ERROR_READ: reading error from fd.
 105      */
 106     ssize_t len;
 107     /* whether buf is null-terminated or not */
 108     gboolean null_term;
 109     /* error code in case of len == MC_PIPE_ERROR_READ */
 110     int error;
 111 } mc_pipe_stream_t;
 112
 113 /* Pipe descriptor for child process */
 114 typedef struct
 115 {
 116     /* PID of child process */
 117     GPid child_pid;
 118     /* stdout of child process */
 119     mc_pipe_stream_t out;
 120     /* stderr of child process */
 121     mc_pipe_stream_t err;
 122 } mc_pipe_t;
 123
 124 /*** structures declarations (and typedefs of structures)*****************************************/
 125
 126 /*** global variables defined in .c file *********************************************************/
 127
 128 extern struct sigaction startup_handler;
 129
 130 /*** declarations of public functions ************************************************************/
 131
 132 int is_printable (int c);
 133
 134 /* Quote the filename for the purpose of inserting it into the command
 135  * line.  If quote_percent is 1, replace "%" with "%%" - the percent is
 136  * processed by the mc command line. */
 137 char *name_quote (const char *c, gboolean quote_percent);
 138
 139 /* returns a duplicate of c. */
 140 char *fake_name_quote (const char *c, gboolean quote_percent);
 141
 142 /* path_trunc() is the same as str_trunc() but
 143  * it deletes possible password from path for security
 144  * reasons. */
 145 const char *path_trunc (const char *path, size_t trunc_len);
 146
 147 /* return a static string representing size, appending "K" or "M" for
 148  * big sizes.
 149  * NOTE: uses the same static buffer as size_trunc_sep. */
 150 const char *size_trunc (uintmax_t size, gboolean use_si);
 151
 152 /* return a static string representing size, appending "K" or "M" for
 153  * big sizes. Separates every three digits by ",".
 154  * NOTE: uses the same static buffer as size_trunc. */
 155 const char *size_trunc_sep (uintmax_t size, gboolean use_si);
 156
 157 /* Print file SIZE to BUFFER, but don't exceed LEN characters,
 158  * not including trailing 0. BUFFER should be at least LEN+1 long.
 159  *
 160  * Units: size units (0=bytes, 1=Kbytes, 2=Mbytes, etc.) */
 161 void size_trunc_len (char *buffer, unsigned int len, uintmax_t size, int units, gboolean use_si);
 162 const char *string_perm (mode_t mode_bits);
 163
 164 const char *extension (const char *);
 165 const char *unix_error_string (int error_num);
 166 const char *skip_separators (const char *s);
 167 const char *skip_numbers (const char *s);
 168 char *strip_ctrl_codes (char *s);
 169
 170 /* Replaces "\\E" and "\\e" with "\033". Replaces "^" + [a-z] with
 171  * ((char) 1 + (c - 'a')). The same goes for "^" + [A-Z].
 172  * Returns a newly allocated string. */
 173 char *convert_controls (const char *s);
 174
 175 /* overwrites passwd with '\0's and frees it. */
 176 void wipe_password (char *passwd);
 177
 178 char *diff_two_paths (const vfs_path_t * vpath1, const vfs_path_t * vpath2);
 179
 180 /* Returns the basename of fname. The result is a pointer into fname. */
 181 const char *x_basename (const char *fname);
 182
 183 char *load_mc_home_file (const char *from, const char *filename, char **allocated_filename,
 184                          size_t * length);
 185
 186 /* uid/gid managing */
 187 void init_groups (void);
 188 void destroy_groups (void);
 189 int get_user_permissions (struct stat *buf);
 190
 191 void init_uid_gid_cache (void);
 192 const char *get_group (gid_t gid);
 193 const char *get_owner (uid_t uid);
 194
 195 /* Returns a copy of *s until a \n is found and is below top */
 196 const char *extract_line (const char *s, const char *top);
 197
 198 /* Process spawning */
 199 int my_system (int flags, const char *shell, const char *command);
 200 int my_systeml (int flags, const char *shell, ...);
 201 int my_systemv (const char *command, char *const argv[]);
 202 int my_systemv_flags (int flags, const char *command, char *const argv[]);
 203
 204 mc_pipe_t *mc_popen (const char *command, gboolean read_out, gboolean read_err, GError ** error);
 205 void mc_pread (mc_pipe_t * p, GError ** error);
 206 void mc_pclose (mc_pipe_t * p, GError ** error);
 207
 208 GString *mc_pstream_get_string (mc_pipe_stream_t * ps);
 209
 210 void my_exit (int status);
 211 void save_stop_handler (void);
 212
 213 /* Tilde expansion */
 214 char *tilde_expand (const char *directory);
 215
 216 void canonicalize_pathname_custom (char *path, canon_path_flags_t flags);
 217
 218 char *mc_realpath (const char *path, char *resolved_path);
 219
 220 /* Looks for "magic" bytes at the start of the VFS file to guess the
 221  * compression type. Side effect: modifies the file position. */
 222 enum compression_type get_compression_type (int fd, const char *name);
 223 const char *decompress_extension (int type);
 224
 225 GList *list_append_unique (GList * list, char *text);
 226
 227 /* Position saving and restoring */
 228 /* Load position for the given filename */
 229 void load_file_position (const vfs_path_t * filename_vpath, long *line, long *column,
 230                          off_t * offset, GArray ** bookmarks);
 231 /* Save position for the given filename */
 232 void save_file_position (const vfs_path_t * filename_vpath, long line, long column, off_t offset,
 233                          GArray * bookmarks);
 234
 235
 236 /* if ch is in [A-Za-z], returns the corresponding control character,
 237  * else returns the argument. */
 238 extern int ascii_alpha_to_cntrl (int ch);
 239
 240 #undef Q_
 241 const char *Q_ (const char *s);
 242
 243 gboolean mc_util_make_backup_if_possible (const char *file_name, const char *backup_suffix);
 244 gboolean mc_util_restore_from_backup_if_possible (const char *file_name, const char *backup_suffix);
 245 gboolean mc_util_unlink_backup_if_possible (const char *file_name, const char *backup_suffix);
 246
 247 char *guess_message_value (void);
 248
 249 char *mc_build_filename (const char *first_element, ...);
 250 char *mc_build_filenamev (const char *first_element, va_list args);
 251
 252 const char *mc_get_profile_root (void);
 253
 254 /* *INDENT-OFF* */
 255 void mc_propagate_error (GError ** dest, int code, const char *format, ...) G_GNUC_PRINTF (3, 4);
 256 void mc_replace_error (GError ** dest, int code, const char *format, ...) G_GNUC_PRINTF (3, 4);
 257 /* *INDENT-ON* */
 258
 259 gboolean mc_time_elapsed (gint64 * timestamp, gint64 delay);
 260
 261 /* --------------------------------------------------------------------------------------------- */
 262 /*** inline functions ****************************************************************************/
 263 /* --------------------------------------------------------------------------------------------- */
 264
 265 static inline gboolean
 266 exist_file (const char *name)
 267 {
 268     return (access (name, R_OK) == 0);
 269 }
 270
 271 /* --------------------------------------------------------------------------------------------- */
 272
 273 static inline gboolean
 274 is_exe (mode_t mode)
 275 {
 276     return ((mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0);
 277 }
 278
 279 /* --------------------------------------------------------------------------------------------- */
 280 /**
 281  * Canonicalize path with CANON_PATH_ALL.
 282  *
 283  * @param path path to file
 284  * @param flags canonicalization flags
 285  *
 286  * All modifications of @path are made in place.
 287  * Well formed UNC paths are modified only in the local part.
 288  */
 289
 290 static inline void
 291 canonicalize_pathname (char *path)
 292 {
 293     canonicalize_pathname_custom (path, CANON_PATH_ALL);
 294 }
 295
 296 /* --------------------------------------------------------------------------------------------- */
 297
 298 #endif /* MC_UTIL_H */