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    Contents of /trunk/mkinitrd-magellan/busybox/coreutils/fold.c

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    Revision 984 - (show annotations) (download)
    Sun May 30 11:32:42 2010 UTC (13 years, 11 months ago) by niro
    File MIME type: text/plain
    File size: 4374 byte(s) 
    -updated to busybox-1.16.1 and enabled blkid/uuid support in default config
    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 #include "libbb.h"
    13 #include "unicode.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(unsigned column, char c)
    24 {
    25 if (option_mask32 & FLAG_COUNT_BYTES)
    26 return ++column;
    27
    28 if (c == '\t')
    29 return column + 8 - column % 8;
    30
    31 if (c == '\b') {
    32 if ((int)--column < 0)
    33 column = 0;
    34 }
    35 else if (c == '\r')
    36 column = 0;
    37 else { /* just a printable char */
    38 if (unicode_status != UNICODE_ON /* every byte is a new char */
    39 || (c & 0xc0) != 0x80 /* it isn't a 2nd+ byte of a Unicode char */
    40 ) {
    41 column++;
    42 }
    43 }
    44 return column;
    45 }
    46
    47 /* Note that this function can write NULs, unlike fputs etc. */
    48 static void write2stdout(const void *buf, unsigned size)
    49 {
    50 fwrite(buf, 1, size, stdout);
    51 }
    52
    53 int fold_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
    54 int fold_main(int argc UNUSED_PARAM, char **argv)
    55 {
    56 char *line_out = NULL;
    57 const char *w_opt = "80";
    58 unsigned width;
    59 smallint exitcode = EXIT_SUCCESS;
    60
    61 init_unicode();
    62
    63 if (ENABLE_INCLUDE_SUSv2) {
    64 /* Turn any numeric options into -w options. */
    65 int i;
    66 for (i = 1; argv[i]; i++) {
    67 const char *a = argv[i];
    68 if (*a == '-') {
    69 a++;
    70 if (*a == '-' && !a[1]) /* "--" */
    71 break;
    72 if (isdigit(*a))
    73 argv[i] = xasprintf("-w%s", a);
    74 }
    75 }
    76 }
    77
    78 getopt32(argv, "bsw:", &w_opt);
    79 width = xatou_range(w_opt, 1, 10000);
    80
    81 argv += optind;
    82 if (!*argv)
    83 *--argv = (char*)"-";
    84
    85 do {
    86 FILE *istream = fopen_or_warn_stdin(*argv);
    87 int c;
    88 unsigned column = 0; /* Screen column where next char will go */
    89 unsigned offset_out = 0; /* Index in 'line_out' for next char */
    90
    91 if (istream == NULL) {
    92 exitcode = EXIT_FAILURE;
    93 continue;
    94 }
    95
    96 while ((c = getc(istream)) != EOF) {
    97 /* We grow line_out in chunks of 0x1000 bytes */
    98 if ((offset_out & 0xfff) == 0) {
    99 line_out = xrealloc(line_out, offset_out + 0x1000);
    100 }
    101 rescan:
    102 line_out[offset_out] = c;
    103 if (c == '\n') {
    104 write2stdout(line_out, offset_out + 1);
    105 column = offset_out = 0;
    106 continue;
    107 }
    108 column = adjust_column(column, c);
    109 if (column <= width || offset_out == 0) {
    110 /* offset_out == 0 case happens
    111 * with small width (say, 1) and tabs.
    112 * The very first tab already goes to column 8,
    113 * but we must not wrap it */
    114 offset_out++;
    115 continue;
    116 }
    117
    118 /* This character would make the line too long.
    119 * Print the line plus a newline, and make this character
    120 * start the next line */
    121 if (option_mask32 & FLAG_BREAK_SPACES) {
    122 unsigned i;
    123 unsigned logical_end;
    124
    125 /* Look for the last blank. */
    126 for (logical_end = offset_out - 1; (int)logical_end >= 0; logical_end--) {
    127 if (!isblank(line_out[logical_end]))
    128 continue;
    129
    130 /* Found a space or tab.
    131 * Output up to and including it, and start a new line */
    132 logical_end++;
    133 /*line_out[logical_end] = '\n'; - NO! this nukes one buffered character */
    134 write2stdout(line_out, logical_end);
    135 putchar('\n');
    136 /* Move the remainder to the beginning of the next line.
    137 * The areas being copied here might overlap. */
    138 memmove(line_out, line_out + logical_end, offset_out - logical_end);
    139 offset_out -= logical_end;
    140 for (column = i = 0; i < offset_out; i++) {
    141 column = adjust_column(column, line_out[i]);
    142 }
    143 goto rescan;
    144 }
    145 /* No blank found, wrap will split the overlong word */
    146 }
    147 /* Output what we accumulated up to now, and start a new line */
    148 line_out[offset_out] = '\n';
    149 write2stdout(line_out, offset_out + 1);
    150 column = offset_out = 0;
    151 goto rescan;
    152 } /* while (not EOF) */
    153
    154 if (offset_out) {
    155 write2stdout(line_out, offset_out);
    156 }
    157
    158 if (fclose_if_not_stdin(istream)) {
    159 bb_simple_perror_msg(*argv);
    160 exitcode = EXIT_FAILURE;
    161 }
    162 } while (*++argv);
    163
    164 fflush_stdout_and_exit(exitcode);
    165 }