colorize.c

   1 /*
   2  * colorize - Read text from standard input stream or file and print
   3  *            it colorized through use of ANSI escape sequences
   4  *
   5  * Copyright (c) 2011-2017 Steven Schubiger
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 #define _DEFAULT_SOURCE
  23 #define _BSD_SOURCE
  24 #define _XOPEN_SOURCE 700
  25 #define _FILE_OFFSET_BITS 64
  26 #include <assert.h>
  27 #include <ctype.h>
  28 #include <errno.h>
  29 #include <getopt.h>
  30 #include <stdarg.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <sys/time.h>
  35 #include <sys/types.h>
  36 #include <sys/stat.h>
  37 #include <time.h>
  38 #include <unistd.h>
  39
  40 #ifndef DEBUG
  41 # define DEBUG 0
  42 #endif
  43
  44 #define str(arg) #arg
  45 #define to_str(arg) str(arg)
  46
  47 #define streq(s1, s2) (strcmp (s1, s2) == 0)
  48 #define strneq(s1, s2, n) (strncmp (s1, s2, n) == 0)
  49
  50 #if !DEBUG
  51 # define xmalloc(size)          malloc_wrap(size)
  52 # define xcalloc(nmemb, size)   calloc_wrap(nmemb, size)
  53 # define xrealloc(ptr, size)    realloc_wrap(ptr, size)
  54 # define xstrdup(str)           strdup_wrap(str,            NULL, 0)
  55 # define str_concat(str1, str2) str_concat_wrap(str1, str2, NULL, 0)
  56 #else
  57 # define xmalloc(size)          malloc_wrap_debug(size,        __FILE__, __LINE__)
  58 # define xcalloc(nmemb, size)   calloc_wrap_debug(nmemb, size, __FILE__, __LINE__)
  59 # define xrealloc(ptr, size)    realloc_wrap_debug(ptr, size,  __FILE__, __LINE__)
  60 # define xstrdup(str)           strdup_wrap(str,               __FILE__, __LINE__)
  61 # define str_concat(str1, str2) str_concat_wrap(str1, str2,    __FILE__, __LINE__)
  62 #endif
  63
  64 #define free_null(ptr) free_wrap((void **)&ptr)
  65
  66 #if defined(BUF_SIZE) && (BUF_SIZE <= 0 || BUF_SIZE > 65536)
  67 # undef BUF_SIZE
  68 #endif
  69 #ifndef BUF_SIZE
  70 # define BUF_SIZE 4096
  71 #endif
  72
  73 #define LF 0x01
  74 #define CR 0x02
  75
  76 #define SKIP_LINE_ENDINGS(flags) (((flags) & CR) && ((flags) & LF) ? 2 : 1)
  77
  78 #define VALID_FILE_TYPE(mode) (S_ISREG (mode) || S_ISLNK (mode) || S_ISFIFO (mode))
  79
  80 #define STACK_VAR(ptr) do {                                   \
  81     stack_var (&vars_list, &stacked_vars, stacked_vars, ptr); \
  82 } while (false)
  83
  84 #define RELEASE_VAR(ptr) do {                             \
  85     release_var (vars_list, stacked_vars, (void **)&ptr); \
  86 } while (false)
  87
  88 #if !DEBUG
  89 # define MEM_ALLOC_FAIL() do {                                         \
  90     fprintf (stderr, "%s: memory allocation failure\n", program_name); \
  91     exit (EXIT_FAILURE);                                               \
  92 } while (false)
  93 #else
  94 # define MEM_ALLOC_FAIL_DEBUG(file, line) do {                                              \
  95     fprintf (stderr, "Memory allocation failure in source file %s, line %u\n", file, line); \
  96     exit (EXIT_FAILURE);                                                                    \
  97 } while (false)
  98 #endif
  99
 100 #define ABORT_TRACE()                                                              \
 101     fprintf (stderr, "Aborting in source file %s, line %u\n", __FILE__, __LINE__); \
 102     abort ();                                                                      \
 103
 104 #define CHECK_COLORS_RANDOM(color1, color2)        \
 105      streq (color_names[color1]->name, "random")   \
 106  && (streq (color_names[color2]->name, "none")     \
 107   || streq (color_names[color2]->name, "default")) \
 108
 109 #define ALLOC_COMPLETE_PART_LINE 8
 110
 111 #if defined(COLOR_SEP_CHAR_COLON)
 112 # define COLOR_SEP_CHAR ':'
 113 #elif defined(COLOR_SEP_CHAR_SLASH)
 114 # define COLOR_SEP_CHAR '/'
 115 #else
 116 # define COLOR_SEP_CHAR '/'
 117 #endif
 118
 119 #define DEBUG_FILE "debug.txt"
 120
 121 #define MAX_ATTRIBUTE_CHARS (5 * 2)
 122
 123 #define VERSION "0.60"
 124
 125 typedef enum { false, true } bool;
 126
 127 struct color_name {
 128     char *name;
 129     char *orig;
 130 };
 131
 132 struct color {
 133     const char *name;
 134     const char *code;
 135 };
 136
 137 static const struct color fg_colors[] = {
 138     { "none",     NULL },
 139     { "black",   "30m" },
 140     { "red",     "31m" },
 141     { "green",   "32m" },
 142     { "yellow",  "33m" },
 143     { "blue",    "34m" },
 144     { "magenta", "35m" },
 145     { "cyan",    "36m" },
 146     { "white",   "37m" },
 147     { "default", "39m" },
 148 };
 149 static const struct color bg_colors[] = {
 150     { "none",     NULL },
 151     { "black",   "40m" },
 152     { "red",     "41m" },
 153     { "green",   "42m" },
 154     { "yellow",  "43m" },
 155     { "blue",    "44m" },
 156     { "magenta", "45m" },
 157     { "cyan",    "46m" },
 158     { "white",   "47m" },
 159     { "default", "49m" },
 160 };
 161
 162 struct bytes_size {
 163     unsigned int size;
 164     char unit;
 165 };
 166
 167 enum fmts {
 168     FMT_GENERIC,
 169     FMT_STRING,
 170     FMT_QUOTE,
 171     FMT_COLOR,
 172     FMT_RANDOM,
 173     FMT_ERROR,
 174     FMT_FILE,
 175     FMT_TYPE
 176 };
 177 static const char *formats[] = {
 178     "%s",                     /* generic */
 179     "%s '%s'",                /* string  */
 180     "%s `%s' %s",             /* quote   */
 181     "%s color '%s' %s",       /* color   */
 182     "%s color '%s' %s '%s'",  /* random  */
 183     "less than %lu bytes %s", /* error   */
 184     "%s: %s",                 /* file    */
 185     "%s: %s: %s",             /* type    */
 186 };
 187
 188 enum { GENERIC, FOREGROUND = 0, BACKGROUND };
 189
 190 static const struct {
 191     struct color const *entries;
 192     unsigned int count;
 193     const char *desc;
 194 } tables[] = {
 195     { fg_colors, sizeof (fg_colors) / sizeof (struct color), "foreground" },
 196     { bg_colors, sizeof (bg_colors) / sizeof (struct color), "background" },
 197 };
 198
 199 enum {
 200     OPT_ATTR = 1,
 201     OPT_CLEAN,
 202     OPT_CLEAN_ALL,
 203     OPT_EXCLUDE_RANDOM,
 204     OPT_HELP,
 205     OPT_VERSION
 206 };
 207 static int opt_type;
 208 static const struct option long_opts[] = {
 209     { "attr",           required_argument, &opt_type, OPT_ATTR           },
 210     { "clean",          no_argument,       &opt_type, OPT_CLEAN          },
 211     { "clean-all",      no_argument,       &opt_type, OPT_CLEAN_ALL      },
 212     { "exclude-random", required_argument, &opt_type, OPT_EXCLUDE_RANDOM },
 213     { "help",           no_argument,       &opt_type, OPT_HELP           },
 214     { "version",        no_argument,       &opt_type, OPT_VERSION        },
 215     {  NULL,            0,                 NULL,      0                  },
 216 };
 217
 218 static FILE *stream;
 219 #if DEBUG
 220 static FILE *log;
 221 #endif
 222
 223 static unsigned int stacked_vars;
 224 static void **vars_list;
 225
 226 static bool clean;
 227 static bool clean_all;
 228
 229 static char attr[MAX_ATTRIBUTE_CHARS + 1];
 230 static char *exclude;
 231
 232 static const char *program_name;
 233
 234 static void process_opts (int, char **);
 235 static void process_opt_attr (const char *);
 236 static void write_attr (unsigned int);
 237 static void print_hint (void);
 238 static void print_help (void);
 239 static void print_version (void);
 240 static void cleanup (void);
 241 static void free_color_names (struct color_name **);
 242 static void process_args (unsigned int, char **, char *, const struct color **, const char **, FILE **);
 243 static void process_file_arg (const char *, const char **, FILE **);
 244 static void skip_path_colors (const char *, const char *, const struct stat *);
 245 static void gather_color_names (const char *, char *, struct color_name **);
 246 static void read_print_stream (const char *, const struct color **, const char *, FILE *);
 247 static void merge_print_line (const char *, const char *, FILE *);
 248 static void complete_part_line (const char *, char **, FILE *);
 249 static bool get_next_char (char *, const char **, FILE *, bool *);
 250 static void save_char (char, char **, size_t *, size_t *);
 251 static void find_color_entries (struct color_name **, const struct color **);
 252 static void find_color_entry (const struct color_name *, unsigned int, const struct color **);
 253 static void print_line (const char *, const struct color **, const char * const, unsigned int);
 254 static void print_clean (const char *);
 255 static bool is_esc (const char *);
 256 static const char *get_end_of_esc (const char *);
 257 static const char *get_end_of_text (const char *);
 258 static void print_text (const char *, size_t);
 259 static bool gather_esc_offsets (const char *, const char **, const char **);
 260 static bool validate_esc_clean_all (const char **);
 261 static bool validate_esc_clean (int, unsigned int, unsigned int *, const char **, bool *);
 262 static bool is_reset (int, unsigned int, const char **);
 263 static bool is_attr (int, unsigned int, unsigned int, const char **);
 264 static bool is_fg_color (int, const char **);
 265 static bool is_bg_color (int, unsigned int, const char **);
 266 #if !DEBUG
 267 static void *malloc_wrap (size_t);
 268 static void *calloc_wrap (size_t, size_t);
 269 static void *realloc_wrap (void *, size_t);
 270 #else
 271 static void *malloc_wrap_debug (size_t, const char *, unsigned int);
 272 static void *calloc_wrap_debug (size_t, size_t, const char *, unsigned int);
 273 static void *realloc_wrap_debug (void *, size_t, const char *, unsigned int);
 274 #endif
 275 static void free_wrap (void **);
 276 static char *strdup_wrap (const char *, const char *, unsigned int);
 277 static char *str_concat_wrap (const char *, const char *, const char *, unsigned int);
 278 static bool get_bytes_size (unsigned long, struct bytes_size *);
 279 static char *get_file_type (mode_t);
 280 static bool has_color_name (const char *, const char *);
 281 static FILE *open_file (const char *, const char *);
 282 static void vfprintf_diag (const char *, ...);
 283 static void vfprintf_fail (const char *, ...);
 284 static void stack_var (void ***, unsigned int *, unsigned int, void *);
 285 static void release_var (void **, unsigned int, void **);
 286
 287 extern int optind;
 288
 289 int
 290 main (int argc, char **argv)
 291 {
 292     unsigned int arg_cnt;
 293
 294     const struct color *colors[2] = {
 295         NULL, /* foreground */
 296         NULL, /* background */
 297     };
 298
 299     const char *file = NULL;
 300
 301     program_name = argv[0];
 302     atexit (cleanup);
 303
 304     setvbuf (stdout, NULL, _IOLBF, 0);
 305
 306 #if DEBUG
 307     log = open_file (DEBUG_FILE, "w");
 308 #endif
 309
 310     attr[0] = '\0';
 311
 312     process_opts (argc, argv);
 313
 314     arg_cnt = argc - optind;
 315
 316     if (clean || clean_all)
 317       {
 318         if (clean && clean_all)
 319           vfprintf_fail (formats[FMT_GENERIC], "--clean and --clean-all switch are mutually exclusive");
 320         if (arg_cnt > 1)
 321           {
 322             const char *format = "%s %s";
 323             const char *message = "switch cannot be used with more than one file";
 324             if (clean)
 325               vfprintf_fail (format, "--clean", message);
 326             else if (clean_all)
 327               vfprintf_fail (format, "--clean-all", message);
 328           }
 329       }
 330     else
 331       {
 332         if (arg_cnt == 0 || arg_cnt > 2)
 333           {
 334             vfprintf_diag ("%u arguments provided, expected 1-2 arguments or clean option", arg_cnt);
 335             print_hint ();
 336             exit (EXIT_FAILURE);
 337           }
 338       }
 339
 340     if (clean || clean_all)
 341       process_file_arg (argv[optind], &file, &stream);
 342     else
 343       process_args (arg_cnt, &argv[optind], &attr[0], colors, &file, &stream);
 344     read_print_stream (&attr[0], colors, file, stream);
 345
 346     RELEASE_VAR (exclude);
 347
 348     exit (EXIT_SUCCESS);
 349 }
 350
 351 #define PRINT_HELP_EXIT() \
 352     print_help ();        \
 353     exit (EXIT_SUCCESS);  \
 354
 355 #define PRINT_VERSION_EXIT() \
 356     print_version ();        \
 357     exit (EXIT_SUCCESS);     \
 358
 359 extern char *optarg;
 360
 361 static void
 362 process_opts (int argc, char **argv)
 363 {
 364     int opt;
 365     while ((opt = getopt_long (argc, argv, "hV", long_opts, NULL)) != -1)
 366       {
 367         switch (opt)
 368           {
 369             case 0: /* long opts */
 370               switch (opt_type)
 371                 {
 372                   case OPT_ATTR:
 373                     process_opt_attr (optarg);
 374                     break;
 375                   case OPT_CLEAN:
 376                     clean = true;
 377                     break;
 378                   case OPT_CLEAN_ALL:
 379                     clean_all = true;
 380                     break;
 381                   case OPT_EXCLUDE_RANDOM: {
 382                     bool valid = false;
 383                     unsigned int i;
 384                     exclude = xstrdup (optarg);
 385                     STACK_VAR (exclude);
 386                     for (i = 1; i < tables[GENERIC].count - 1; i++) /* skip color none and default */
 387                       {
 388                         const struct color *entry = &tables[GENERIC].entries[i];
 389                         if (streq (exclude, entry->name))
 390                           {
 391                             valid = true;
 392                             break;
 393                           }
 394                       }
 395                     if (!valid)
 396                       vfprintf_fail (formats[FMT_GENERIC], "--exclude-random switch must be provided a plain color");
 397                     break;
 398                   }
 399                   case OPT_HELP:
 400                     PRINT_HELP_EXIT ();
 401                   case OPT_VERSION:
 402                     PRINT_VERSION_EXIT ();
 403                   default: /* never reached */
 404                     ABORT_TRACE ();
 405                 }
 406               break;
 407             case 'h':
 408               PRINT_HELP_EXIT ();
 409             case 'V':
 410               PRINT_VERSION_EXIT ();
 411             case '?':
 412               print_hint ();
 413               exit (EXIT_FAILURE);
 414             default: /* never reached */
 415               ABORT_TRACE ();
 416           }
 417       }
 418 }
 419
 420 static void
 421 process_opt_attr (const char *p)
 422 {
 423     while (*p)
 424       {
 425         const char *s;
 426         if (!isalnum (*p))
 427           vfprintf_fail (formats[FMT_GENERIC], "--attr switch must be provided a string");
 428         s = p;
 429         while (isalnum (*p))
 430           p++;
 431         if (*p != '\0' && *p != ',')
 432           vfprintf_fail (formats[FMT_GENERIC], "--attr switch must have strings separated by ,");
 433         else
 434           {
 435             /* If attributes are added to this "list", also increase MAX_ATTRIBUTE_CHARS!  */
 436             if (p - s == 4 && strneq (s, "bold", 4))
 437               write_attr (1);
 438             else if (p - s == 10 && strneq (s, "underscore", 10))
 439               write_attr (4);
 440             else if (p - s == 5 && strneq (s, "blink", 5))
 441               write_attr (5);
 442             else if (p - s == 7 && strneq (s, "reverse", 7))
 443               write_attr (7);
 444             else if (p - s == 9 && strneq (s, "concealed", 9))
 445               write_attr (8);
 446             else
 447               vfprintf_fail (formats[FMT_GENERIC], "--attr switch must be provided valid attribute names");
 448           }
 449         if (*p)
 450           p++;
 451       }
 452 }
 453
 454 static void
 455 write_attr (unsigned int val)
 456 {
 457     snprintf (attr + strlen (attr), 3, "%u;", val);
 458 }
 459
 460 static void
 461 print_hint (void)
 462 {
 463     fprintf (stderr, "Type `%s --help' for help screen.\n", program_name);
 464 }
 465
 466 static void
 467 print_help (void)
 468 {
 469     struct short_opt {
 470         const char *name;
 471         const char *short_opt;
 472     };
 473     const struct short_opt short_opts[] = {
 474         { "help",    "h" },
 475         { "version", "V" },
 476     };
 477     const struct option *opt = long_opts;
 478     unsigned int i;
 479
 480     printf ("Usage: %s (foreground) OR (foreground)%c(background) OR --clean[-all] [-|file]\n\n", program_name, COLOR_SEP_CHAR);
 481     printf ("\tColors (foreground) (background)\n");
 482     for (i = 0; i < tables[FOREGROUND].count; i++)
 483       {
 484         const struct color *entry = &tables[FOREGROUND].entries[i];
 485         const char *name = entry->name;
 486         const char *code = entry->code;
 487         if (code)
 488           printf ("\t\t{\033[%s#\033[0m} [%c%c]%s%*s%s\n",
 489                    code, toupper (*name), *name, name + 1, 10 - (int)strlen (name), " ", name);
 490         else
 491           printf ("\t\t{-} %s%*s%s\n", name, 13 - (int)strlen (name), " ", name);
 492       }
 493     printf ("\t\t{*} [Rr]%s%*s%s [--exclude-random=<foreground color>]\n", "andom", 10 - (int)strlen ("random"), " ", "random");
 494
 495     printf ("\n\tFirst character of color name in upper case denotes increased intensity,\n");
 496     printf ("\twhereas for lower case colors will be of normal intensity.\n");
 497
 498     printf ("\n\tOptions\n");
 499     for (; opt->name; opt++)
 500       {
 501         const char *short_opt = NULL;
 502         unsigned int i;
 503         for (i = 0; i < sizeof (short_opts) / sizeof (struct short_opt); i++)
 504           {
 505             if (streq (opt->name, short_opts[i].name))
 506               {
 507                 short_opt = short_opts[i].short_opt;
 508                 break;
 509               }
 510           }
 511         if (short_opt)
 512           printf ("\t\t-%s, --%s\n", short_opt, opt->name);
 513         else
 514           printf ("\t\t    --%s\n", opt->name);
 515       }
 516     printf ("\n");
 517 }
 518
 519 static void
 520 print_version (void)
 521 {
 522 #ifdef HAVE_VERSION
 523 # include "version.h"
 524 #else
 525     const char *version = NULL;
 526 #endif
 527     const char *version_prefix, *version_string;
 528     const char *c_flags, *ld_flags, *cpp_flags;
 529     struct bytes_size bytes_size;
 530     bool debug;
 531 #ifdef CFLAGS
 532     c_flags = to_str (CFLAGS);
 533 #else
 534     c_flags = "unknown";
 535 #endif
 536 #ifdef LDFLAGS
 537     ld_flags = to_str (LDFLAGS);
 538 #else
 539     ld_flags = "unknown";
 540 #endif
 541 #ifdef CPPFLAGS
 542     cpp_flags = to_str (CPPFLAGS);
 543 #else
 544     cpp_flags = "unknown";
 545 #endif
 546 #if DEBUG
 547     debug = true;
 548 #else
 549     debug = false;
 550 #endif
 551     version_prefix = version ? "" : "v";
 552     version_string = version ? version : VERSION;
 553     printf ("colorize %s%s (compiled at %s, %s)\n", version_prefix, version_string, __DATE__, __TIME__);
 554
 555     printf ("Compiler flags: %s\n", c_flags);
 556     printf ("Linker flags: %s\n", ld_flags);
 557     printf ("Preprocessor flags: %s\n", cpp_flags);
 558     if (get_bytes_size (BUF_SIZE, &bytes_size))
 559       {
 560         if (BUF_SIZE % 1024 == 0)
 561           printf ("Buffer size: %u%c\n", bytes_size.size, bytes_size.unit);
 562         else
 563           printf ("Buffer size: %u%c, %u byte%s\n", bytes_size.size, bytes_size.unit,
 564                    BUF_SIZE % 1024, BUF_SIZE % 1024 > 1 ? "s" : "");
 565       }
 566     else
 567       printf ("Buffer size: %lu byte%s\n", (unsigned long)BUF_SIZE, BUF_SIZE > 1 ? "s" : "");
 568     printf ("Color separator: '%c'\n", COLOR_SEP_CHAR);
 569     printf ("Debugging: %s\n", debug ? "yes" : "no");
 570 }
 571
 572 static void
 573 cleanup (void)
 574 {
 575     if (stream && fileno (stream) != STDIN_FILENO)
 576       fclose (stream);
 577 #if DEBUG
 578     if (log)
 579       fclose (log);
 580 #endif
 581
 582     if (vars_list)
 583       {
 584         unsigned int i;
 585         for (i = 0; i < stacked_vars; i++)
 586           free (vars_list[i]);
 587         free_null (vars_list);
 588       }
 589 }
 590
 591 static void
 592 free_color_names (struct color_name **color_names)
 593 {
 594     unsigned int i;
 595     for (i = 0; color_names[i]; i++)
 596       {
 597         RELEASE_VAR (color_names[i]->name);
 598         RELEASE_VAR (color_names[i]->orig);
 599         RELEASE_VAR (color_names[i]);
 600       }
 601 }
 602
 603 static void
 604 process_args (unsigned int arg_cnt, char **arg_strings, char *attr, const struct color **colors, const char **file, FILE **stream)
 605 {
 606     int ret;
 607     char *p;
 608     struct stat sb;
 609     struct color_name *color_names[3] = { NULL, NULL, NULL };
 610
 611     const char *color_string = arg_cnt >= 1 ? arg_strings[0] : NULL;
 612     const char *file_string  = arg_cnt == 2 ? arg_strings[1] : NULL;
 613
 614     assert (color_string);
 615
 616     if (streq (color_string, "-"))
 617       {
 618         if (file_string)
 619           vfprintf_fail (formats[FMT_GENERIC], "hyphen cannot be used as color string");
 620         else
 621           vfprintf_fail (formats[FMT_GENERIC], "hyphen must be preceded by color string");
 622       }
 623
 624     ret = lstat (color_string, &sb);
 625
 626     /* Ensure that we don't fail if there's a file with one or more
 627        color names in its path.  */
 628     if (ret == 0) /* success */
 629       skip_path_colors (color_string, file_string, &sb);
 630
 631     if ((p = strchr (color_string, COLOR_SEP_CHAR)))
 632       {
 633         if (p == color_string)
 634           vfprintf_fail (formats[FMT_STRING], "foreground color missing in string", color_string);
 635         else if (p == color_string + strlen (color_string) - 1)
 636           vfprintf_fail (formats[FMT_STRING], "background color missing in string", color_string);
 637         else if (strchr (++p, COLOR_SEP_CHAR))
 638           vfprintf_fail (formats[FMT_STRING], "one color pair allowed only for string", color_string);
 639       }
 640
 641     gather_color_names (color_string, attr, color_names);
 642
 643     assert (color_names[FOREGROUND]);
 644
 645     if (color_names[BACKGROUND])
 646       {
 647         unsigned int i;
 648         const unsigned int color_sets[2][2] = { { FOREGROUND, BACKGROUND }, { BACKGROUND, FOREGROUND } };
 649         for (i = 0; i < 2; i++)
 650           {
 651             const unsigned int color1 = color_sets[i][0];
 652             const unsigned int color2 = color_sets[i][1];
 653             if (CHECK_COLORS_RANDOM (color1, color2))
 654               vfprintf_fail (formats[FMT_RANDOM], tables[color1].desc, color_names[color1]->orig, "cannot be combined with", color_names[color2]->orig);
 655           }
 656       }
 657
 658     find_color_entries (color_names, colors);
 659     free_color_names (color_names);
 660
 661     if (!colors[FOREGROUND]->code && colors[BACKGROUND] && colors[BACKGROUND]->code)
 662       {
 663         struct color_name color_name;
 664         color_name.name = color_name.orig = "default";
 665
 666         find_color_entry (&color_name, FOREGROUND, colors);
 667       }
 668
 669     process_file_arg (file_string, file, stream);
 670 }
 671
 672 static void
 673 process_file_arg (const char *file_string, const char **file, FILE **stream)
 674 {
 675     if (file_string)
 676       {
 677         if (streq (file_string, "-"))
 678           *stream = stdin;
 679         else
 680           {
 681             const char *file = file_string;
 682             struct stat sb;
 683             int ret;
 684
 685             errno = 0;
 686             ret = stat (file, &sb);
 687
 688             if (ret == -1)
 689               vfprintf_fail (formats[FMT_FILE], file, strerror (errno));
 690
 691             if (!VALID_FILE_TYPE (sb.st_mode))
 692               vfprintf_fail (formats[FMT_TYPE], file, "unrecognized type", get_file_type (sb.st_mode));
 693
 694             *stream = open_file (file, "r");
 695           }
 696         *file = file_string;
 697       }
 698     else
 699       {
 700         *stream = stdin;
 701         *file = "stdin";
 702       }
 703
 704     assert (*stream);
 705     assert (*file);
 706 }
 707
 708 static void
 709 skip_path_colors (const char *color_string, const char *file_string, const struct stat *sb)
 710 {
 711     bool have_file;
 712     unsigned int c;
 713     const char *color = color_string;
 714     const mode_t mode = sb->st_mode;
 715
 716     for (c = 1; c <= 2 && *color; c++)
 717       {
 718         bool matched = false;
 719         unsigned int i;
 720         for (i = 0; i < tables[GENERIC].count; i++)
 721           {
 722             const struct color *entry = &tables[GENERIC].entries[i];
 723             if (has_color_name (color, entry->name))
 724               {
 725                 color += strlen (entry->name);
 726                 matched = true;
 727                 break;
 728               }
 729           }
 730         if (!matched && has_color_name (color, "random"))
 731           {
 732             color += strlen ("random");
 733             matched = true;
 734           }
 735         if (matched && *color == COLOR_SEP_CHAR && *(color + 1))
 736           color++;
 737         else
 738           break;
 739       }
 740
 741     have_file = (*color != '\0');
 742
 743     if (have_file)
 744       {
 745         const char *file_exists = color_string;
 746         if (file_string)
 747           vfprintf_fail (formats[FMT_QUOTE], get_file_type (mode), file_exists, "cannot be used as color string");
 748         else
 749           {
 750             if (VALID_FILE_TYPE (mode))
 751               vfprintf_fail (formats[FMT_QUOTE], get_file_type (mode), file_exists, "must be preceded by color string");
 752             else
 753               vfprintf_fail (formats[FMT_QUOTE], get_file_type (mode), file_exists, "is not a valid file type");
 754           }
 755       }
 756 }
 757
 758 static void
 759 gather_color_names (const char *color_string, char *attr, struct color_name **color_names)
 760 {
 761     unsigned int index;
 762     char *color, *p, *str;
 763
 764     str = xstrdup (color_string);
 765     STACK_VAR (str);
 766
 767     for (index = 0, color = str; *color; index++, color = p)
 768       {
 769         char *ch, *sep;
 770
 771         p = NULL;
 772         if ((sep = strchr (color, COLOR_SEP_CHAR)))
 773           {
 774             *sep = '\0';
 775             p = sep + 1;
 776           }
 777         else
 778           p = color + strlen (color);
 779         assert (p);
 780
 781         for (ch = color; *ch; ch++)
 782           if (!isalpha (*ch))
 783             vfprintf_fail (formats[FMT_COLOR], tables[index].desc, color, "cannot be made of non-alphabetic characters");
 784
 785         for (ch = color + 1; *ch; ch++)
 786           if (!islower (*ch))
 787             vfprintf_fail (formats[FMT_COLOR], tables[index].desc, color, "cannot be in mixed lower/upper case");
 788
 789         if (streq (color, "None"))
 790           vfprintf_fail (formats[FMT_COLOR], tables[index].desc, color, "cannot be bold");
 791
 792         if (isupper (*color))
 793           {
 794             switch (index)
 795               {
 796                 case FOREGROUND:
 797                   snprintf (attr + strlen (attr), 3, "1;");
 798                   break;
 799                 case BACKGROUND:
 800                   vfprintf_fail (formats[FMT_COLOR], tables[BACKGROUND].desc, color, "cannot be bold");
 801                 default: /* never reached */
 802                   ABORT_TRACE ();
 803               }
 804           }
 805
 806         color_names[index] = xcalloc (1, sizeof (struct color_name));
 807         STACK_VAR (color_names[index]);
 808
 809         color_names[index]->orig = xstrdup (color);
 810         STACK_VAR (color_names[index]->orig);
 811
 812         for (ch = color; *ch; ch++)
 813           *ch = tolower (*ch);
 814
 815         color_names[index]->name = xstrdup (color);
 816         STACK_VAR (color_names[index]->name);
 817       }
 818
 819     RELEASE_VAR (str);
 820 }
 821
 822 static void
 823 read_print_stream (const char *attr, const struct color **colors, const char *file, FILE *stream)
 824 {
 825     char buf[BUF_SIZE + 1];
 826     unsigned int flags = 0;
 827
 828     while (!feof (stream))
 829       {
 830         size_t bytes_read;
 831         char *eol;
 832         const char *line;
 833         bytes_read = fread (buf, 1, BUF_SIZE, stream);
 834         if (bytes_read != BUF_SIZE && ferror (stream))
 835           vfprintf_fail (formats[FMT_ERROR], BUF_SIZE, "read");
 836         buf[bytes_read] = '\0';
 837         line = buf;
 838         while ((eol = strpbrk (line, "\n\r")))
 839           {
 840             const char *p;
 841             flags &= ~(CR|LF);
 842             if (*eol == '\r')
 843               {
 844                 flags |= CR;
 845                 if (*(eol + 1) == '\n')
 846                   flags |= LF;
 847               }
 848             else if (*eol == '\n')
 849               flags |= LF;
 850             else
 851               vfprintf_fail (formats[FMT_FILE], file, "unrecognized line ending");
 852             p = eol + SKIP_LINE_ENDINGS (flags);
 853             *eol = '\0';
 854             print_line (attr, colors, line, flags);
 855             line = p;
 856           }
 857         if (feof (stream))
 858           {
 859             if (*line != '\0')
 860               print_line (attr, colors, line, 0);
 861           }
 862         else if (*line != '\0')
 863           {
 864             char *p;
 865             if ((clean || clean_all) && (p = strrchr (line, '\033')))
 866               merge_print_line (line, p, stream);
 867             else
 868               print_line (attr, colors, line, 0);
 869           }
 870       }
 871 }
 872
 873 static void
 874 merge_print_line (const char *line, const char *p, FILE *stream)
 875 {
 876     char *buf = NULL;
 877     char *merged_esc = NULL;
 878     const char *esc = "";
 879     const char char_restore = *p;
 880
 881     complete_part_line (p + 1, &buf, stream);
 882
 883     if (buf)
 884       {
 885         /* form escape sequence */
 886         esc = merged_esc = str_concat (p, buf);
 887         /* shorten partial line accordingly */
 888         *(char *)p = '\0';
 889         free (buf);
 890       }
 891
 892 #ifdef TEST_MERGE_PART_LINE
 893     printf ("%s%s", line, esc);
 894     fflush (stdout);
 895     _exit (EXIT_SUCCESS);
 896 #else
 897     print_clean (line);
 898     *(char *)p = char_restore;
 899     print_clean (esc);
 900     free (merged_esc);
 901 #endif
 902 }
 903
 904 static void
 905 complete_part_line (const char *p, char **buf, FILE *stream)
 906 {
 907     bool got_next_char = false, read_from_stream;
 908     char ch;
 909     size_t i = 0, size;
 910
 911     if (get_next_char (&ch, &p, stream, &read_from_stream))
 912       {
 913         if (ch == '[')
 914           {
 915             if (read_from_stream)
 916               save_char (ch, buf, &i, &size);
 917           }
 918         else
 919           {
 920             if (read_from_stream)
 921               ungetc ((int)ch, stream);
 922             return; /* cancel */
 923           }
 924       }
 925     else
 926       return; /* cancel */
 927
 928     while (get_next_char (&ch, &p, stream, &read_from_stream))
 929       {
 930         if (isdigit (ch) || ch == ';')
 931           {
 932             if (read_from_stream)
 933               save_char (ch, buf, &i, &size);
 934           }
 935         else /* read next character */
 936           {
 937             got_next_char = true;
 938             break;
 939           }
 940       }
 941
 942     if (got_next_char)
 943       {
 944         if (ch == 'm')
 945           {
 946             if (read_from_stream)
 947               save_char (ch, buf, &i, &size);
 948           }
 949         else
 950           {
 951             if (read_from_stream)
 952               ungetc ((int)ch, stream);
 953             return; /* cancel */
 954           }
 955       }
 956     else
 957       return; /* cancel */
 958 }
 959
 960 static bool
 961 get_next_char (char *ch, const char **p, FILE *stream, bool *read_from_stream)
 962 {
 963     if (**p == '\0')
 964       {
 965         int c;
 966         if ((c = fgetc (stream)) != EOF)
 967           {
 968             *ch = (char)c;
 969             *read_from_stream = true;
 970             return true;
 971           }
 972         else
 973           {
 974             *read_from_stream = false;
 975             return false;
 976           }
 977       }
 978     else
 979       {
 980         *ch = **p;
 981         (*p)++;
 982         *read_from_stream = false;
 983         return true;
 984       }
 985 }
 986
 987 static void
 988 save_char (char ch, char **buf, size_t *i, size_t *size)
 989 {
 990     if (!*buf)
 991       {
 992         *size = ALLOC_COMPLETE_PART_LINE;
 993         *buf = xmalloc (*size);
 994       }
 995     /* +1: effective occupied size of buffer */
 996     else if ((*i + 1) == *size)
 997       {
 998         *size *= 2;
 999         *buf = xrealloc (*buf, *size);
1000       }
1001     (*buf)[*i] = ch;
1002     (*buf)[*i + 1] = '\0';
1003     (*i)++;
1004 }
1005
1006 static void
1007 find_color_entries (struct color_name **color_names, const struct color **colors)
1008 {
1009     struct timeval tv;
1010     unsigned int index;
1011
1012     /* randomness */
1013     gettimeofday (&tv, NULL);
1014     srand (tv.tv_usec * tv.tv_sec);
1015
1016     for (index = 0; color_names[index]; index++)
1017       {
1018         const char *color_name = color_names[index]->name;
1019
1020         const unsigned int count                = tables[index].count;
1021         const struct color *const color_entries = tables[index].entries;
1022
1023         if (streq (color_name, "random"))
1024           {
1025             bool excludable;
1026             unsigned int i;
1027             do {
1028               excludable = false;
1029               i = rand() % (count - 2) + 1; /* omit color none and default */
1030               switch (index)
1031                 {
1032                   case FOREGROUND:
1033                     /* --exclude-random */
1034                     if (exclude && streq (exclude, color_entries[i].name))
1035                       excludable = true;
1036                     else if (color_names[BACKGROUND] && streq (color_names[BACKGROUND]->name, color_entries[i].name))
1037                       excludable = true;
1038                     break;
1039                   case BACKGROUND:
1040                     if (streq (colors[FOREGROUND]->name, color_entries[i].name))
1041                       excludable = true;
1042                     break;
1043                   default: /* never reached */
1044                     ABORT_TRACE ();
1045                  }
1046             } while (excludable);
1047             colors[index] = (struct color *)&color_entries[i];
1048           }
1049         else
1050           find_color_entry (color_names[index], index, colors);
1051       }
1052 }
1053
1054 static void
1055 find_color_entry (const struct color_name *color_name, unsigned int index, const struct color **colors)
1056 {
1057     bool found = false;
1058     unsigned int i;
1059
1060     const unsigned int count                = tables[index].count;
1061     const struct color *const color_entries = tables[index].entries;
1062
1063     for (i = 0; i < count; i++)
1064       if (streq (color_name->name, color_entries[i].name))
1065         {
1066           colors[index] = (struct color *)&color_entries[i];
1067           found = true;
1068           break;
1069         }
1070     if (!found)
1071       vfprintf_fail (formats[FMT_COLOR], tables[index].desc, color_name->orig, "not recognized");
1072 }
1073
1074 static void
1075 print_line (const char *attr, const struct color **colors, const char *const line, unsigned int flags)
1076 {
1077     /* --clean[-all] */
1078     if (clean || clean_all)
1079       print_clean (line);
1080     else
1081       {
1082         /* Foreground color code is guaranteed to be set when background color code is present.  */
1083         if (colors[BACKGROUND] && colors[BACKGROUND]->code)
1084           printf ("\033[%s", colors[BACKGROUND]->code);
1085         if (colors[FOREGROUND]->code)
1086           printf ("\033[%s%s%s\033[0m", attr, colors[FOREGROUND]->code, line);
1087         else
1088           printf (formats[FMT_GENERIC], line);
1089       }
1090     if (flags & CR)
1091       putchar ('\r');
1092     if (flags & LF)
1093       putchar ('\n');
1094 }
1095
1096 static void
1097 print_clean (const char *line)
1098 {
1099     const char *p = line;
1100
1101     if (is_esc (p))
1102       p = get_end_of_esc (p);
1103
1104     while (*p != '\0')
1105       {
1106         const char *text_start = p;
1107         const char *text_end = get_end_of_text (p);
1108         print_text (text_start, text_end - text_start);
1109         p = get_end_of_esc (text_end);
1110       }
1111 }
1112
1113 static bool
1114 is_esc (const char *p)
1115 {
1116     return gather_esc_offsets (p, NULL, NULL);
1117 }
1118
1119 static const char *
1120 get_end_of_esc (const char *p)
1121 {
1122     const char *esc;
1123     const char *end = NULL;
1124     while ((esc = strchr (p, '\033')))
1125       {
1126         if (gather_esc_offsets (esc, NULL, &end))
1127           break;
1128         p = esc + 1;
1129       }
1130     return end ? end + 1 : p + strlen (p);
1131 }
1132
1133 static const char *
1134 get_end_of_text (const char *p)
1135 {
1136     const char *esc;
1137     const char *start = NULL;
1138     while ((esc = strchr (p, '\033')))
1139       {
1140         if (gather_esc_offsets (esc, &start, NULL))
1141           break;
1142         p = esc + 1;
1143       }
1144     return start ? start : p + strlen (p);
1145 }
1146
1147 static void
1148 print_text (const char *p, size_t len)
1149 {
1150     size_t bytes_written;
1151     bytes_written = fwrite (p, 1, len, stdout);
1152     if (bytes_written != len)
1153       vfprintf_fail (formats[FMT_ERROR], (unsigned long)len, "written");
1154 }
1155
1156 static bool
1157 gather_esc_offsets (const char *p, const char **start, const char **end)
1158 {
1159     /* ESC[ */
1160     if (*p == 27 && *(p + 1) == '[')
1161       {
1162         bool valid = false;
1163         const char *const begin = p;
1164         p += 2;
1165         if (clean_all)
1166           valid = validate_esc_clean_all (&p);
1167         else if (clean)
1168           {
1169             bool check_values;
1170             unsigned int prev_iter, iter;
1171             const char *digit;
1172             prev_iter = iter = 0;
1173             do {
1174               check_values = false;
1175               iter++;
1176               if (!isdigit (*p))
1177                 break;
1178               digit = p;
1179               while (isdigit (*p))
1180                 p++;
1181               if (p - digit > 2)
1182                 break;
1183               else /* check range */
1184                 {
1185                   char val[3];
1186                   int value;
1187                   unsigned int i;
1188                   const unsigned int digits = p - digit;
1189                   for (i = 0; i < digits; i++)
1190                     val[i] = *digit++;
1191                   val[i] = '\0';
1192                   value = atoi (val);
1193                   valid = validate_esc_clean (value, iter, &prev_iter, &p, &check_values);
1194                 }
1195             } while (check_values);
1196           }
1197         if (valid)
1198           {
1199             if (start)
1200               *start = begin;
1201             if (end)
1202               *end = p;
1203             return true;
1204           }
1205       }
1206     return false;
1207 }
1208
1209 static bool
1210 validate_esc_clean_all (const char **p)
1211 {
1212     while (isdigit (**p) || **p == ';')
1213       (*p)++;
1214     return (**p == 'm');
1215 }
1216
1217 static bool
1218 validate_esc_clean (int value, unsigned int iter, unsigned int *prev_iter, const char **p, bool *check_values)
1219 {
1220     if (is_reset (value, iter, p))
1221       return true;
1222     else if (is_attr (value, iter, *prev_iter, p))
1223       {
1224         (*p)++;
1225         *check_values = true;
1226         *prev_iter = iter;
1227         return false; /* partial escape sequence, need another valid value */
1228       }
1229     else if (is_fg_color (value, p))
1230       return true;
1231     else if (is_bg_color (value, iter, p))
1232       return true;
1233     else
1234       return false;
1235 }
1236
1237 static bool
1238 is_reset (int value, unsigned int iter, const char **p)
1239 {
1240     return (value == 0 && iter == 1 && **p == 'm');
1241 }
1242
1243 static bool
1244 is_attr (int value, unsigned int iter, unsigned int prev_iter, const char **p)
1245 {
1246     return ((value > 0 && value < 10) && (iter - prev_iter == 1) && **p == ';');
1247 }
1248
1249 static bool
1250 is_fg_color (int value, const char **p)
1251 {
1252     return (((value >= 30 && value <= 37) || value == 39) && **p == 'm');
1253 }
1254
1255 static bool
1256 is_bg_color (int value, unsigned int iter, const char **p)
1257 {
1258     return (((value >= 40 && value <= 47) || value == 49) && iter == 1 && **p == 'm');
1259 }
1260
1261 #if !DEBUG
1262 static void *
1263 malloc_wrap (size_t size)
1264 {
1265     void *p = malloc (size);
1266     if (!p)
1267       MEM_ALLOC_FAIL ();
1268     return p;
1269 }
1270
1271 static void *
1272 calloc_wrap (size_t nmemb, size_t size)
1273 {
1274     void *p = calloc (nmemb, size);
1275     if (!p)
1276       MEM_ALLOC_FAIL ();
1277     return p;
1278 }
1279
1280 static void *
1281 realloc_wrap (void *ptr, size_t size)
1282 {
1283     void *p = realloc (ptr, size);
1284     if (!p)
1285       MEM_ALLOC_FAIL ();
1286     return p;
1287 }
1288 #else
1289 static void *
1290 malloc_wrap_debug (size_t size, const char *file, unsigned int line)
1291 {
1292     void *p = malloc (size);
1293     if (!p)
1294       MEM_ALLOC_FAIL_DEBUG (file, line);
1295     fprintf (log, "%s: malloc'ed %lu bytes [source file %s, line %u]\n", program_name, (unsigned long)size, file, line);
1296     return p;
1297 }
1298
1299 static void *
1300 calloc_wrap_debug (size_t nmemb, size_t size, const char *file, unsigned int line)
1301 {
1302     void *p = calloc (nmemb, size);
1303     if (!p)
1304       MEM_ALLOC_FAIL_DEBUG (file, line);
1305     fprintf (log, "%s: calloc'ed %lu bytes [source file %s, line %u]\n", program_name, (unsigned long)(nmemb * size), file, line);
1306     return p;
1307 }
1308
1309 static void *
1310 realloc_wrap_debug (void *ptr, size_t size, const char *file, unsigned int line)
1311 {
1312     void *p = realloc (ptr, size);
1313     if (!p)
1314       MEM_ALLOC_FAIL_DEBUG (file, line);
1315     fprintf (log, "%s: realloc'ed %lu bytes [source file %s, line %u]\n", program_name, (unsigned long)size, file, line);
1316     return p;
1317 }
1318 #endif /* !DEBUG */
1319
1320 static void
1321 free_wrap (void **ptr)
1322 {
1323     free (*ptr);
1324     *ptr = NULL;
1325 }
1326
1327 #if !DEBUG
1328 # define do_malloc(len, file, line) malloc_wrap(len)
1329 #else
1330 # define do_malloc(len, file, line) malloc_wrap_debug(len, file, line)
1331 #endif
1332
1333 static char *
1334 strdup_wrap (const char *str, const char *file, unsigned int line)
1335 {
1336     const size_t len = strlen (str) + 1;
1337     char *p = do_malloc (len, file, line);
1338     strncpy (p, str, len);
1339     return p;
1340 }
1341
1342 static char *
1343 str_concat_wrap (const char *str1, const char *str2, const char *file, unsigned int line)
1344 {
1345     const size_t len = strlen (str1) + strlen (str2) + 1;
1346     char *p, *str;
1347
1348     p = str = do_malloc (len, file, line);
1349     strncpy (p, str1, strlen (str1));
1350     p += strlen (str1);
1351     strncpy (p, str2, strlen (str2));
1352     p += strlen (str2);
1353     *p = '\0';
1354
1355     return str;
1356 }
1357
1358 static bool
1359 get_bytes_size (unsigned long bytes, struct bytes_size *bytes_size)
1360 {
1361     const char *unit, units[] = { '0', 'K', 'M', 'G', '\0' };
1362     unsigned long size = bytes;
1363     if (bytes < 1024)
1364       return false;
1365     unit = units;
1366     while (size >= 1024 && *(unit + 1))
1367       {
1368         size /= 1024;
1369         unit++;
1370       }
1371     bytes_size->size = (unsigned int)size;
1372     bytes_size->unit = *unit;
1373     return true;
1374 }
1375
1376 static char *
1377 get_file_type (mode_t mode)
1378 {
1379     if (S_ISREG (mode))
1380       return "file";
1381     else if (S_ISDIR (mode))
1382       return "directory";
1383     else if (S_ISCHR (mode))
1384       return "character device";
1385     else if (S_ISBLK (mode))
1386       return "block device";
1387     else if (S_ISFIFO (mode))
1388       return "named pipe";
1389     else if (S_ISLNK (mode))
1390       return "symbolic link";
1391     else if (S_ISSOCK (mode))
1392       return "socket";
1393     else
1394       return "file";
1395 }
1396
1397 static bool
1398 has_color_name (const char *str, const char *name)
1399 {
1400     char *p;
1401
1402     assert (strlen (str));
1403     assert (strlen (name));
1404
1405     if (!(*str == *name || *str == toupper (*name)))
1406       return false;
1407     else if (*(name + 1) != '\0'
1408      && !((p = strstr (str + 1, name + 1)) && p == str + 1))
1409       return false;
1410
1411     return true;
1412 }
1413
1414 static FILE *
1415 open_file (const char *file, const char *mode)
1416 {
1417     FILE *stream;
1418
1419     errno = 0;
1420     stream = fopen (file, mode);
1421     if (!stream)
1422       vfprintf_fail (formats[FMT_FILE], file, strerror (errno));
1423
1424     return stream;
1425 }
1426
1427 #define DO_VFPRINTF(fmt)                    \
1428     va_list ap;                             \
1429     fprintf (stderr, "%s: ", program_name); \
1430     va_start (ap, fmt);                     \
1431     vfprintf (stderr, fmt, ap);             \
1432     va_end (ap);                            \
1433     fprintf (stderr, "\n");                 \
1434
1435 static void
1436 vfprintf_diag (const char *fmt, ...)
1437 {
1438     DO_VFPRINTF (fmt);
1439 }
1440
1441 static void
1442 vfprintf_fail (const char *fmt, ...)
1443 {
1444     DO_VFPRINTF (fmt);
1445     exit (EXIT_FAILURE);
1446 }
1447
1448 static void
1449 stack_var (void ***list, unsigned int *stacked, unsigned int index, void *ptr)
1450 {
1451     /* nothing to stack */
1452     if (ptr == NULL)
1453       return;
1454     if (!*list)
1455       *list = xmalloc (sizeof (void *));
1456     else
1457       {
1458         unsigned int i;
1459         for (i = 0; i < *stacked; i++)
1460           if (!(*list)[i])
1461             {
1462               (*list)[i] = ptr;
1463               return; /* reused */
1464             }
1465         *list = xrealloc (*list, (*stacked + 1) * sizeof (void *));
1466       }
1467     (*list)[index] = ptr;
1468     (*stacked)++;
1469 }
1470
1471 static void
1472 release_var (void **list, unsigned int stacked, void **ptr)
1473 {
1474     unsigned int i;
1475     /* nothing to release */
1476     if (*ptr == NULL)
1477       return;
1478     for (i = 0; i < stacked; i++)
1479       if (list[i] == *ptr)
1480         {
1481           free (*ptr);
1482           *ptr = NULL;
1483           list[i] = NULL;
1484           return;
1485         }
1486 }