coreutils/ls.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * tiny-ls.c version 0.1.0: A minimalist 'ls'
   4  * Copyright (C) 1996 Brian Candler <B.Candler@pobox.com>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20
  21 /*
  22  * To achieve a small memory footprint, this version of 'ls' doesn't do any
  23  * file sorting, and only has the most essential command line switches
  24  * (i.e. the ones I couldn't live without :-) All features which involve
  25  * linking in substantial chunks of libc can be disabled.
  26  *
  27  * Although I don't really want to add new features to this program to
  28  * keep it small, I *am* interested to receive bug fixes and ways to make
  29  * it more portable.
  30  *
  31  * KNOWN BUGS:
  32  * 1. ls -l of a directory doesn't give "total <blocks>" header
  33  * 2. ls of a symlink to a directory doesn't list directory contents
  34  * 3. hidden files can make column width too large
  35  *
  36  * NON-OPTIMAL BEHAVIOUR:
  37  * 1. autowidth reads directories twice
  38  * 2. if you do a short directory listing without filetype characters
  39  *    appended, there's no need to stat each one
  40  * PORTABILITY:
  41  * 1. requires lstat (BSD) - how do you do it without?
  42  */
  43
  44 #define TERMINAL_WIDTH  80              /* use 79 if your terminal has linefold bug */
  45 #define COLUMN_WIDTH    14              /* default if AUTOWIDTH not defined */
  46 #define COLUMN_GAP      2                       /* includes the file type char, if present */
  47 #define HAS_REWINDDIR
  48
  49 /************************************************************************/
  50
  51 #include "internal.h"
  52 # include <sys/types.h>
  53 #include <sys/stat.h>
  54 #include <stdio.h>
  55 #include <unistd.h>
  56 #include <dirent.h>
  57 #include <errno.h>
  58 #include <stdio.h>
  59 #ifdef BB_FEATURE_LS_TIMESTAMPS
  60 #include <time.h>
  61 #endif
  62
  63 #define TYPEINDEX(mode) (((mode) >> 12) & 0x0f)
  64 #define TYPECHAR(mode)  ("0pcCd?bB-?l?s???" [TYPEINDEX(mode)])
  65 #ifdef BB_FEATURE_LS_FILETYPES
  66 #define APPCHAR(mode)   ("\0|\0\0/\0\0\0\0\0@\0=\0\0\0" [TYPEINDEX(mode)])
  67 #endif
  68
  69 #define FMT_AUTO        0
  70 #define FMT_LONG        1                       /* one record per line, extended info */
  71 #define FMT_SINGLE      2                       /* one record per line */
  72 #define FMT_ROWS        3                       /* print across rows */
  73 #define FMT_COLUMNS     3                       /* fill columns (same, since we don't sort) */
  74
  75 #define TIME_MOD        0
  76 #define TIME_CHANGE     1
  77 #define TIME_ACCESS     2
  78
  79 #define DISP_FTYPE      1                       /* show character for file type */
  80 #define DISP_EXEC       2                       /* show '*' if regular executable file */
  81 #define DISP_HIDDEN     4                       /* show files starting . (except . and ..) */
  82 #define DISP_DOT        8                       /* show . and .. */
  83 #define DISP_NUMERIC    16              /* numeric uid and gid */
  84 #define DISP_FULLTIME   32              /* show extended time display */
  85 #define DIR_NOLIST              64              /* show directory as itself, not contents */
  86 #define DISP_DIRNAME    128             /* show directory name (for internal use) */
  87 #define DISP_RECURSIVE  256             /* Do a recursive listing */
  88
  89 #ifndef MAJOR
  90 #define MAJOR(dev) (((dev)>>8)&0xff)
  91 #define MINOR(dev) ((dev)&0xff)
  92 #endif
  93
  94 static unsigned char display_fmt = FMT_AUTO;
  95 static unsigned short opts = 0;
  96 static unsigned short column = 0;
  97
  98 #ifdef BB_FEATURE_AUTOWIDTH
  99 static unsigned short terminal_width = 0;
 100 static unsigned short column_width = 0;
 101 static unsigned short toplevel_column_width = 0;
 102 #else
 103 #define terminal_width  TERMINAL_WIDTH
 104 #define column_width    COLUMN_WIDTH
 105 #endif
 106
 107 #ifdef BB_FEATURE_LS_TIMESTAMPS
 108 static unsigned char time_fmt = TIME_MOD;
 109 #endif
 110
 111 #define wr(data,len) fwrite(data, 1, len, stdout)
 112
 113 static void writenum(long val, short minwidth)
 114 {
 115         char scratch[128];
 116
 117         char *p = scratch + sizeof(scratch);
 118         short len = 0;
 119         short neg = (val < 0);
 120
 121         if (neg)
 122                 val = -val;
 123         do
 124                 *--p = (val % 10) + '0', len++, val /= 10;
 125         while (val);
 126         if (neg)
 127                 *--p = '-', len++;
 128         while (len < minwidth)
 129                 *--p = ' ', len++;
 130         wr(p, len);
 131         column += len;
 132 }
 133
 134 static void newline(void)
 135 {
 136         if (column > 0) {
 137                 wr("\n", 1);
 138                 column = 0;
 139         }
 140 }
 141
 142 static void tab(short col)
 143 {
 144         static const char spaces[] = "                ";
 145
 146 #define nspaces ((sizeof spaces)-1)     /* null terminator! */
 147
 148         short n = col - column;
 149
 150         if (n > 0) {
 151                 column = col;
 152                 while (n > nspaces) {
 153                         wr(spaces, nspaces);
 154                         n -= nspaces;
 155                 }
 156                 /* must be 1...(sizeof spaces) left */
 157                 wr(spaces, n);
 158         }
 159 #undef nspaces
 160 }
 161
 162 #ifdef BB_FEATURE_LS_FILETYPES
 163 static char append_char(mode_t mode)
 164 {
 165         if (!(opts & DISP_FTYPE))
 166                 return '\0';
 167         if ((opts & DISP_EXEC) && S_ISREG(mode)
 168                 && (mode & (S_IXUSR | S_IXGRP | S_IXOTH))) return '*';
 169         return APPCHAR(mode);
 170 }
 171 #endif
 172
 173 /**
 174  **
 175  ** Display a file or directory as a single item
 176  ** (in either long or short format)
 177  **
 178  **/
 179
 180 static void list_single(const char *name, struct stat *info,
 181                                                 const char *fullname)
 182 {
 183         char scratch[BUFSIZ + 1];
 184         short len = strlen(name);
 185
 186 #ifdef BB_FEATURE_LS_FILETYPES
 187         char append = append_char(info->st_mode);
 188 #endif
 189
 190         if (display_fmt == FMT_LONG) {
 191                 mode_t mode = info->st_mode;
 192
 193                 newline();
 194                 wr(modeString(mode), 10);
 195                 column = 10;
 196                 writenum((long) info->st_nlink, (short) 5);
 197                 fputs(" ", stdout);
 198 #ifdef BB_FEATURE_LS_USERNAME
 199                 if (!(opts & DISP_NUMERIC)) {
 200                         memset(scratch, 0, sizeof(scratch));
 201                         my_getpwuid(scratch, info->st_uid);
 202                         if (*scratch) {
 203                                 fputs(scratch, stdout);
 204                                 if (strlen(scratch) <= 8)
 205                                         wr("          ", 9 - strlen(scratch));
 206                         } else {
 207                                 writenum((long) info->st_uid, (short) 8);
 208                                 fputs(" ", stdout);
 209                         }
 210                 } else
 211 #endif
 212                 {
 213                         writenum((long) info->st_uid, (short) 8);
 214                         fputs(" ", stdout);
 215                 }
 216 #ifdef BB_FEATURE_LS_USERNAME
 217                 if (!(opts & DISP_NUMERIC)) {
 218                         memset(scratch, 0, sizeof(scratch));
 219                         my_getgrgid(scratch, info->st_gid);
 220                         if (*scratch) {
 221                                 fputs(scratch, stdout);
 222                                 if (strlen(scratch) <= 8)
 223                                         wr("         ", 8 - strlen(scratch));
 224                         } else
 225                                 writenum((long) info->st_gid, (short) 8);
 226                 } else
 227 #endif
 228                         writenum((long) info->st_gid, (short) 8);
 229                 //tab(26);
 230                 if (S_ISBLK(mode) || S_ISCHR(mode)) {
 231                         writenum((long) MAJOR(info->st_rdev), (short) 3);
 232                         fputs(", ", stdout);
 233                         writenum((long) MINOR(info->st_rdev), (short) 3);
 234                 } else
 235                         writenum((long) info->st_size, (short) 8);
 236                 fputs(" ", stdout);
 237                 //tab(32);
 238 #ifdef BB_FEATURE_LS_TIMESTAMPS
 239                 {
 240                         time_t cal;
 241                         char *string;
 242
 243                         switch (time_fmt) {
 244                         case TIME_CHANGE:
 245                                 cal = info->st_ctime;
 246                                 break;
 247                         case TIME_ACCESS:
 248                                 cal = info->st_atime;
 249                                 break;
 250                         default:
 251                                 cal = info->st_mtime;
 252                                 break;
 253                         }
 254                         string = ctime(&cal);
 255                         if (opts & DISP_FULLTIME)
 256                                 wr(string, 24);
 257                         else {
 258                                 time_t age = time(NULL) - cal;
 259
 260                                 wr(string + 4, 7);      /* mmm_dd_ */
 261                                 if (age < 3600L * 24 * 365 / 2 && age > -15 * 60)
 262                                         /* hh:mm if less than 6 months old */
 263                                         wr(string + 11, 5);
 264                                 else
 265                                         /* _yyyy otherwise */
 266                                         wr(string + 19, 5);
 267                         }
 268                         wr(" ", 1);
 269                 }
 270 #else
 271                 fputs("--- -- ----- ", stdout);
 272 #endif
 273                 wr(name, len);
 274                 if (S_ISLNK(mode)) {
 275                         wr(" -> ", 4);
 276                         len = readlink(fullname, scratch, sizeof scratch);
 277                         if (len > 0)
 278                                 fwrite(scratch, 1, len, stdout);
 279 #ifdef BB_FEATURE_LS_FILETYPES
 280                         /* show type of destination */
 281                         if (opts & DISP_FTYPE) {
 282                                 if (!stat(fullname, info)) {
 283                                         append = append_char(info->st_mode);
 284                                         if (append)
 285                                                 fputc(append, stdout);
 286                                 }
 287                         }
 288 #endif
 289                 }
 290 #ifdef BB_FEATURE_LS_FILETYPES
 291                 else if (append)
 292                         wr(&append, 1);
 293 #endif
 294         } else {
 295                 static short nexttab = 0;
 296
 297                 /* sort out column alignment */
 298                 if (column == 0);               /* nothing to do */
 299                 else if (display_fmt == FMT_SINGLE)
 300                         newline();
 301                 else {
 302                         if (nexttab + column_width > terminal_width
 303 #ifndef BB_FEATURE_AUTOWIDTH
 304                                 || nexttab + len >= terminal_width
 305 #endif
 306                                 )
 307                                 newline();
 308                         else
 309                                 tab(nexttab);
 310                 }
 311                 /* work out where next column starts */
 312 #ifdef BB_FEATURE_AUTOWIDTH
 313                 /* we know the calculated width is big enough */
 314                 nexttab = column + column_width + COLUMN_GAP;
 315 #else
 316                 /* might cover more than one fixed-width column */
 317                 nexttab = column;
 318                 do
 319                         nexttab += column_width + COLUMN_GAP;
 320                 while (nexttab < (column + len + COLUMN_GAP));
 321 #endif
 322                 /* now write the data */
 323                 wr(name, len);
 324                 column = column + len;
 325 #ifdef BB_FEATURE_LS_FILETYPES
 326                 if (append)
 327                         wr(&append, 1), column++;
 328 #endif
 329         }
 330 }
 331
 332 /**
 333  **
 334  ** List the given file or directory, expanding a directory
 335  ** to show its contents if required
 336  **
 337  **/
 338
 339 static int list_item(const char *name)
 340 {
 341         struct stat info;
 342         DIR *dir;
 343         struct dirent *entry;
 344         char fullname[BUFSIZ + 1], *fnend;
 345
 346         if (lstat(name, &info))
 347                 goto listerr;
 348
 349         if (!S_ISDIR(info.st_mode) || (opts & DIR_NOLIST)) {
 350 #ifdef BB_FEATURE_AUTOWIDTH
 351                 column_width = toplevel_column_width;
 352 #endif
 353                 list_single(name, &info, name);
 354                 return 0;
 355         }
 356
 357         /* Otherwise, it's a directory we want to list the contents of */
 358
 359         if (opts & DISP_DIRNAME) {      /* identify the directory */
 360                 if (column)
 361                         wr("\n\n", 2), column = 0;
 362                 wr(name, strlen(name));
 363                 wr(":\n", 2);
 364         }
 365
 366         dir = opendir(name);
 367         if (!dir)
 368                 goto listerr;
 369 #ifdef BB_FEATURE_AUTOWIDTH
 370         column_width = 0;
 371         while ((entry = readdir(dir)) != NULL) {
 372                 short w = strlen(entry->d_name);
 373
 374                 if (column_width < w)
 375                         column_width = w;
 376         }
 377 #ifdef HAS_REWINDDIR
 378         rewinddir(dir);
 379 #else
 380         closedir(dir);
 381         dir = opendir(name);
 382         if (!dir)
 383                 goto listerr;
 384 #endif
 385 #endif
 386
 387         /* List the contents */
 388
 389         strcpy(fullname, name);         /* *** ignore '.' by itself */
 390         fnend = fullname + strlen(fullname);
 391         if (fnend[-1] != '/')
 392                 *fnend++ = '/';
 393
 394         while ((entry = readdir(dir)) != NULL) {
 395                 const char *en = entry->d_name;
 396
 397                 if (en[0] == '.') {
 398                         if (!en[1] || (en[1] == '.' && !en[2])) {       /* . or .. */
 399                                 if (!(opts & DISP_DOT))
 400                                         continue;
 401                         } else if (!(opts & DISP_HIDDEN))
 402                                 continue;
 403                 }
 404                 /* FIXME: avoid stat if not required */
 405                 strcpy(fnend, entry->d_name);
 406                 if (lstat(fullname, &info))
 407                         goto direrr;            /* (shouldn't fail) */
 408                 list_single(entry->d_name, &info, fullname);
 409         }
 410         closedir(dir);
 411
 412         if (opts & DISP_DIRNAME) {      /* separate the directory */
 413                 if (column) {
 414                         wr("\n", 1);
 415                 }
 416                 wr("\n", 1);
 417                 column = 0;
 418         }
 419
 420         return 0;
 421
 422   direrr:
 423         closedir(dir);
 424   listerr:
 425         newline();
 426         perror(name);
 427         return 1;
 428 }
 429
 430 #ifdef BB_FEATURE_LS_RECURSIVE
 431 static int dirAction(const char *fileName, struct stat *statbuf, void* junk)
 432 {
 433         int i;
 434         fprintf(stdout, "\n%s:\n", fileName);
 435         i = list_item(fileName);
 436         newline();
 437         return (i);
 438 }
 439 #endif
 440
 441 extern int ls_main(int argc, char **argv)
 442 {
 443         int argi = 1, i;
 444
 445         /* process options */
 446         while (argi < argc && argv[argi][0] == '-') {
 447                 const char *p = &argv[argi][1];
 448
 449                 if (!*p)
 450                         goto print_usage_message;       /* "-" by itself not allowed */
 451                 if (*p == '-') {
 452                         if (!p[1]) {            /* "--" forces end of options */
 453                                 argi++;
 454                                 break;
 455                         }
 456                         /* it's a long option name - we don't support them */
 457                         goto print_usage_message;
 458                 }
 459
 460                 while (*p)
 461                         switch (*p++) {
 462                         case 'l':
 463                                 display_fmt = FMT_LONG;
 464                                 break;
 465                         case '1':
 466                                 display_fmt = FMT_SINGLE;
 467                                 break;
 468                         case 'x':
 469                                 display_fmt = FMT_ROWS;
 470                                 break;
 471                         case 'C':
 472                                 display_fmt = FMT_COLUMNS;
 473                                 break;
 474 #ifdef BB_FEATURE_LS_FILETYPES
 475                         case 'p':
 476                                 opts |= DISP_FTYPE;
 477                                 break;
 478                         case 'F':
 479                                 opts |= DISP_FTYPE | DISP_EXEC;
 480                                 break;
 481 #endif
 482                         case 'A':
 483                                 opts |= DISP_HIDDEN;
 484                                 break;
 485                         case 'a':
 486                                 opts |= DISP_HIDDEN | DISP_DOT;
 487                                 break;
 488                         case 'n':
 489                                 opts |= DISP_NUMERIC;
 490                                 break;
 491                         case 'd':
 492                                 opts |= DIR_NOLIST;
 493                                 break;
 494 #ifdef BB_FEATURE_LS_TIMESTAMPS
 495                         case 'u':
 496                                 time_fmt = TIME_ACCESS;
 497                                 break;
 498                         case 'c':
 499                                 time_fmt = TIME_CHANGE;
 500                                 break;
 501                         case 'e':
 502                                 opts |= DISP_FULLTIME;
 503                                 break;
 504 #endif
 505 #ifdef BB_FEATURE_LS_RECURSIVE
 506                         case 'R':
 507                                 opts |= DISP_RECURSIVE;
 508                                 break;
 509 #endif
 510                         case 'g': /* ignore -- for ftp servers */
 511                                 break;
 512                         default:
 513                                 goto print_usage_message;
 514                         }
 515
 516                 argi++;
 517         }
 518
 519         /* choose a display format */
 520         if (display_fmt == FMT_AUTO)
 521                 display_fmt = isatty(fileno(stdout)) ? FMT_COLUMNS : FMT_SINGLE;
 522         if (argi < argc - 1)
 523                 opts |= DISP_DIRNAME;   /* 2 or more items? label directories */
 524 #ifdef BB_FEATURE_AUTOWIDTH
 525         /* could add a -w option and/or TIOCGWINSZ call */
 526         if (terminal_width < 1)
 527                 terminal_width = TERMINAL_WIDTH;
 528
 529         for (i = argi; i < argc; i++) {
 530                 int len = strlen(argv[i]);
 531
 532                 if (toplevel_column_width < len)
 533                         toplevel_column_width = len;
 534         }
 535 #endif
 536
 537         /* process files specified, or current directory if none */
 538 #ifdef BB_FEATURE_LS_RECURSIVE
 539         if (opts & DISP_RECURSIVE) {
 540                 i = 0;
 541                 if (argi == argc) {
 542                         i = recursiveAction(".", TRUE, FALSE, FALSE, NULL, dirAction, NULL);
 543                 }
 544                 while (argi < argc) {
 545                         i |= recursiveAction(argv[argi++], TRUE, FALSE, FALSE, NULL, dirAction, NULL);
 546                 }
 547         } else
 548 #endif
 549         {
 550                 i = 0;
 551                 if (argi == argc)
 552                         i = list_item(".");
 553                 while (argi < argc)
 554                         i |= list_item(argv[argi++]);
 555                 newline();
 556         }
 557         exit(i);
 558
 559   print_usage_message:
 560         usage(ls_usage);
 561         exit(FALSE);
 562 }