coreutils/wc.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * wc implementation for busybox
   4  *
   5  * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9 /* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
  10  *
  11  * Rewritten to fix a number of problems and do some size optimizations.
  12  * Problems in the previous busybox implementation (besides bloat) included:
  13  *  1) broken 'wc -c' optimization (read note below)
  14  *  2) broken handling of '-' args
  15  *  3) no checking of ferror on EOF returns
  16  *  4) isprint() wasn't considered when word counting.
  17  *
  18  * NOTES:
  19  *
  20  * The previous busybox wc attempted an optimization using stat for the
  21  * case of counting chars only.  I omitted that because it was broken.
  22  * It didn't take into account the possibility of input coming from a
  23  * pipe, or input from a file with file pointer not at the beginning.
  24  *
  25  * To implement such a speed optimization correctly, not only do you
  26  * need the size, but also the file position.  Note also that the
  27  * file position may be past the end of file.  Consider the example
  28  * (adapted from example in gnu wc.c)
  29  *
  30  *      echo hello > /tmp/testfile &&
  31  *      (dd ibs=1k skip=1 count=0 &> /dev/null; wc -c) < /tmp/testfile
  32  *
  33  * for which 'wc -c' should output '0'.
  34  */
  35 //config:config WC
  36 //config:       bool "wc (4.7 kb)"
  37 //config:       default y
  38 //config:       help
  39 //config:       wc is used to print the number of bytes, words, and lines,
  40 //config:       in specified files.
  41 //config:
  42 //config:config FEATURE_WC_LARGE
  43 //config:       bool "Support very large counts"
  44 //config:       default y
  45 //config:       depends on WC
  46 //config:       help
  47 //config:       Use "unsigned long long" for counter variables.
  48
  49 //applet:IF_WC(APPLET(wc, BB_DIR_USR_BIN, BB_SUID_DROP))
  50
  51 //kbuild:lib-$(CONFIG_WC) += wc.o
  52
  53 /* BB_AUDIT SUSv3 compliant. */
  54 /* http://www.opengroup.org/onlinepubs/007904975/utilities/wc.html */
  55
  56 #include "libbb.h"
  57 #include "unicode.h"
  58
  59 #if !ENABLE_LOCALE_SUPPORT
  60 # undef isprint
  61 # undef isspace
  62 # define isprint(c) ((unsigned)((c) - 0x20) <= (0x7e - 0x20))
  63 # define isspace(c) ((c) == ' ')
  64 #endif
  65
  66 #if ENABLE_FEATURE_WC_LARGE
  67 # define COUNT_T unsigned long long
  68 # define COUNT_FMT "llu"
  69 #else
  70 # define COUNT_T unsigned
  71 # define COUNT_FMT "u"
  72 #endif
  73
  74 /* We support -m even when UNICODE_SUPPORT is off,
  75  * we just don't advertise it in help text,
  76  * since it is the same as -c in this case.
  77  */
  78
  79 //usage:#define wc_trivial_usage
  80 //usage:       "[-c"IF_UNICODE_SUPPORT("m")"lwL] [FILE]..."
  81 //usage:
  82 //usage:#define wc_full_usage "\n\n"
  83 //usage:       "Count lines, words, and bytes for FILEs (or stdin)\n"
  84 //usage:     "\n        -c      Count bytes"
  85 //usage:        IF_UNICODE_SUPPORT(
  86 //usage:     "\n        -m      Count characters"
  87 //usage:        )
  88 //usage:     "\n        -l      Count newlines"
  89 //usage:     "\n        -w      Count words"
  90 //usage:     "\n        -L      Print longest line length"
  91 //usage:
  92 //usage:#define wc_example_usage
  93 //usage:       "$ wc /etc/passwd\n"
  94 //usage:       "     31      46    1365 /etc/passwd\n"
  95
  96 /* Order is important if we want to be compatible with
  97  * column order in "wc -cmlwL" output:
  98  */
  99 enum {
 100         WC_LINES    = 0, /* -l */
 101         WC_WORDS    = 1, /* -w */
 102         WC_UNICHARS = 2, /* -m */
 103         WC_BYTES    = 3, /* -c */
 104         WC_LENGTH   = 4, /* -L */
 105         NUM_WCS     = 5,
 106 };
 107
 108 int wc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 109 int wc_main(int argc UNUSED_PARAM, char **argv)
 110 {
 111         const char *arg;
 112         const char *start_fmt = " %9"COUNT_FMT + 1;
 113         const char *fname_fmt = " %s\n";
 114         COUNT_T *pcounts;
 115         COUNT_T counts[NUM_WCS];
 116         COUNT_T totals[NUM_WCS];
 117         int num_files;
 118         smallint status = EXIT_SUCCESS;
 119         unsigned print_type;
 120
 121         init_unicode();
 122
 123         print_type = getopt32(argv, "lwmcL");
 124
 125         if (print_type == 0) {
 126                 print_type = (1 << WC_LINES) | (1 << WC_WORDS) | (1 << WC_BYTES);
 127         }
 128
 129         argv += optind;
 130         if (!argv[0]) {
 131                 *--argv = (char *) bb_msg_standard_input;
 132                 fname_fmt = "\n";
 133         }
 134         if (!argv[1]) { /* zero or one filename? */
 135                 if (!((print_type-1) & print_type)) /* exactly one option? */
 136                         start_fmt = "%"COUNT_FMT;
 137         }
 138
 139         memset(totals, 0, sizeof(totals));
 140
 141         pcounts = counts;
 142
 143         num_files = 0;
 144         while ((arg = *argv++) != NULL) {
 145                 FILE *fp;
 146                 const char *s;
 147                 unsigned u;
 148                 unsigned linepos;
 149                 smallint in_word;
 150
 151                 ++num_files;
 152                 fp = fopen_or_warn_stdin(arg);
 153                 if (!fp) {
 154                         status = EXIT_FAILURE;
 155                         continue;
 156                 }
 157
 158                 memset(counts, 0, sizeof(counts));
 159                 linepos = 0;
 160                 in_word = 0;
 161
 162                 while (1) {
 163                         int c;
 164                         /* Our -w doesn't match GNU wc exactly... oh well */
 165
 166                         c = getc(fp);
 167                         if (c == EOF) {
 168                                 if (ferror(fp)) {
 169                                         bb_simple_perror_msg(arg);
 170                                         status = EXIT_FAILURE;
 171                                 }
 172                                 goto DO_EOF;  /* Treat an EOF as '\r'. */
 173                         }
 174
 175                         /* Cater for -c and -m */
 176                         ++counts[WC_BYTES];
 177                         if (unicode_status != UNICODE_ON /* every byte is a new char */
 178                          || (c & 0xc0) != 0x80 /* it isn't a 2nd+ byte of a Unicode char */
 179                         ) {
 180                                 ++counts[WC_UNICHARS];
 181                         }
 182
 183                         if (isprint_asciionly(c)) { /* FIXME: not unicode-aware */
 184                                 ++linepos;
 185                                 if (!isspace(c)) {
 186                                         in_word = 1;
 187                                         continue;
 188                                 }
 189                         } else if ((unsigned)(c - 9) <= 4) {
 190                                 /* \t  9
 191                                  * \n 10
 192                                  * \v 11
 193                                  * \f 12
 194                                  * \r 13
 195                                  */
 196                                 if (c == '\t') {
 197                                         linepos = (linepos | 7) + 1;
 198                                 } else {  /* '\n', '\r', '\f', or '\v' */
 199  DO_EOF:
 200                                         if (linepos > counts[WC_LENGTH]) {
 201                                                 counts[WC_LENGTH] = linepos;
 202                                         }
 203                                         if (c == '\n') {
 204                                                 ++counts[WC_LINES];
 205                                         }
 206                                         if (c != '\v') {
 207                                                 linepos = 0;
 208                                         }
 209                                 }
 210                         } else {
 211                                 continue;
 212                         }
 213
 214                         counts[WC_WORDS] += in_word;
 215                         in_word = 0;
 216                         if (c == EOF) {
 217                                 break;
 218                         }
 219                 }
 220
 221                 fclose_if_not_stdin(fp);
 222
 223                 if (totals[WC_LENGTH] < counts[WC_LENGTH]) {
 224                         totals[WC_LENGTH] = counts[WC_LENGTH];
 225                 }
 226                 totals[WC_LENGTH] -= counts[WC_LENGTH];
 227
 228  OUTPUT:
 229                 /* coreutils wc tries hard to print pretty columns
 230                  * (saves results for all files, finds max col len etc...)
 231                  * we won't try that hard, it will bloat us too much */
 232                 s = start_fmt;
 233                 u = 0;
 234                 do {
 235                         if (print_type & (1 << u)) {
 236                                 printf(s, pcounts[u]);
 237                                 s = " %9"COUNT_FMT; /* Ok... restore the leading space. */
 238                         }
 239                         totals[u] += pcounts[u];
 240                 } while (++u < NUM_WCS);
 241                 printf(fname_fmt, arg);
 242         }
 243
 244         /* If more than one file was processed, we want the totals.  To save some
 245          * space, we set the pcounts ptr to the totals array.  This has the side
 246          * effect of trashing the totals array after outputting it, but that's
 247          * irrelavent since we no longer need it. */
 248         if (num_files > 1) {
 249                 num_files = 0;  /* Make sure we don't get here again. */
 250                 arg = "total";
 251                 pcounts = totals;
 252                 --argv;
 253                 goto OUTPUT;
 254         }
 255
 256         fflush_stdout_and_exit(status);
 257 }