git.maemo.org Git - busybox4maemo/blob - coreutils/fold.c

   1 /* vi: set sw=4 ts=4: */
   2 /* fold -- wrap each input line to fit in specified width.
   3
   4    Written by David MacKenzie, djm@gnu.ai.mit.edu.
   5    Copyright (C) 91, 1995-2002 Free Software Foundation, Inc.
   6
   7    Modified for busybox based on coreutils v 5.0
   8    Copyright (C) 2003 Glenn McGrath
   9
  10    Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  11 */
  12
  13 #include "libbb.h"
  14
  15 /* Must match getopt32 call */
  16 #define FLAG_COUNT_BYTES        1
  17 #define FLAG_BREAK_SPACES       2
  18 #define FLAG_WIDTH              4
  19
  20 /* Assuming the current column is COLUMN, return the column that
  21    printing C will move the cursor to.
  22    The first column is 0. */
  23 static int adjust_column(int column, char c)
  24 {
  25         if (!(option_mask32 & FLAG_COUNT_BYTES)) {
  26                 if (c == '\b') {
  27                         if (column > 0)
  28                                 column--;
  29                 } else if (c == '\r')
  30                         column = 0;
  31                 else if (c == '\t')
  32                         column = column + 8 - column % 8;
  33                 else                    /* if (isprint (c)) */
  34                         column++;
  35         } else
  36                 column++;
  37         return column;
  38 }
  39
  40 int fold_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  41 int fold_main(int argc, char **argv)
  42 {
  43         char *line_out = NULL;
  44         int allocated_out = 0;
  45         char *w_opt;
  46         int width = 80;
  47         int i;
  48         int errs = 0;
  49
  50         if (ENABLE_INCLUDE_SUSv2) {
  51                 /* Turn any numeric options into -w options.  */
  52                 for (i = 1; i < argc; i++) {
  53                         char const *a = argv[i];
  54
  55                         if (*a++ == '-') {
  56                                 if (*a == '-' && !a[1]) /* "--" */
  57                                         break;
  58                                 if (isdigit(*a))
  59                                         argv[i] = xasprintf("-w%s", a);
  60                         }
  61                 }
  62         }
  63
  64         getopt32(argv, "bsw:", &w_opt);
  65         if (option_mask32 & FLAG_WIDTH)
  66                 width = xatoul_range(w_opt, 1, 10000);
  67
  68         argv += optind;
  69         if (!*argv)
  70                 *--argv = (char*)"-";
  71
  72         do {
  73                 FILE *istream = fopen_or_warn_stdin(*argv);
  74                 int c;
  75                 int column = 0;         /* Screen column where next char will go. */
  76                 int offset_out = 0;     /* Index in 'line_out' for next char. */
  77
  78                 if (istream == NULL) {
  79                         errs |= EXIT_FAILURE;
  80                         continue;
  81                 }
  82
  83                 while ((c = getc(istream)) != EOF) {
  84                         if (offset_out + 1 >= allocated_out) {
  85                                 allocated_out += 1024;
  86                                 line_out = xrealloc(line_out, allocated_out);
  87                         }
  88
  89                         if (c == '\n') {
  90                                 line_out[offset_out++] = c;
  91                                 fwrite(line_out, sizeof(char), (size_t) offset_out, stdout);
  92                                 column = offset_out = 0;
  93                                 continue;
  94                         }
  95  rescan:
  96                         column = adjust_column(column, c);
  97
  98                         if (column > width) {
  99                                 /* This character would make the line too long.
 100                                    Print the line plus a newline, and make this character
 101                                    start the next line. */
 102                                 if (option_mask32 & FLAG_BREAK_SPACES) {
 103                                         /* Look for the last blank. */
 104                                         int logical_end;
 105
 106                                         for (logical_end = offset_out - 1; logical_end >= 0; logical_end--) {
 107                                                 if (isblank(line_out[logical_end])) {
 108                                                         break;
 109                                                 }
 110                                         }
 111                                         if (logical_end >= 0) {
 112                                                 /* Found a blank.  Don't output the part after it. */
 113                                                 logical_end++;
 114                                                 fwrite(line_out, sizeof(char), (size_t) logical_end, stdout);
 115                                                 bb_putchar('\n');
 116                                                 /* Move the remainder to the beginning of the next line.
 117                                                    The areas being copied here might overlap. */
 118                                                 memmove(line_out, line_out + logical_end, offset_out - logical_end);
 119                                                 offset_out -= logical_end;
 120                                                 for (column = i = 0; i < offset_out; i++) {
 121                                                         column = adjust_column(column, line_out[i]);
 122                                                 }
 123                                                 goto rescan;
 124                                         }
 125                                 } else {
 126                                         if (offset_out == 0) {
 127                                                 line_out[offset_out++] = c;
 128                                                 continue;
 129                                         }
 130                                 }
 131                                 line_out[offset_out++] = '\n';
 132                                 fwrite(line_out, sizeof(char), (size_t) offset_out, stdout);
 133                                 column = offset_out = 0;
 134                                 goto rescan;
 135                         }
 136
 137                         line_out[offset_out++] = c;
 138                 }
 139
 140                 if (offset_out) {
 141                         fwrite(line_out, sizeof(char), (size_t) offset_out, stdout);
 142                 }
 143
 144                 if (fclose_if_not_stdin(istream)) {
 145                         bb_simple_perror_msg(*argv);    /* Avoid multibyte problems. */
 146                         errs |= EXIT_FAILURE;
 147                 }
 148         } while (*++argv);
 149
 150         fflush_stdout_and_exit(errs);
 151 }