[3320] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /* fold -- wrap each input line to fit in specified width.
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| 3 |
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| 4 | Written by David MacKenzie, djm@gnu.ai.mit.edu.
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| 5 | Copyright (C) 91, 1995-2002 Free Software Foundation, Inc.
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| 6 |
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| 7 | Modified for busybox based on coreutils v 5.0
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| 8 | Copyright (C) 2003 Glenn McGrath
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| 9 |
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| 10 | Licensed under GPLv2 or later, see file LICENSE in this source tree.
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| 11 | */
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| 12 | #include "libbb.h"
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| 13 | #include "unicode.h"
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| 14 |
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| 15 | /* This is a NOEXEC applet. Be very careful! */
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| 16 |
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| 17 | /* Must match getopt32 call */
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| 18 | #define FLAG_COUNT_BYTES 1
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| 19 | #define FLAG_BREAK_SPACES 2
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| 20 | #define FLAG_WIDTH 4
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| 21 |
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| 22 | /* Assuming the current column is COLUMN, return the column that
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| 23 | printing C will move the cursor to.
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| 24 | The first column is 0. */
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| 25 | static int adjust_column(unsigned column, char c)
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| 26 | {
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| 27 | if (option_mask32 & FLAG_COUNT_BYTES)
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| 28 | return ++column;
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| 29 |
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| 30 | if (c == '\t')
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| 31 | return column + 8 - column % 8;
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| 32 |
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| 33 | if (c == '\b') {
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| 34 | if ((int)--column < 0)
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| 35 | column = 0;
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| 36 | }
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| 37 | else if (c == '\r')
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| 38 | column = 0;
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| 39 | else { /* just a printable char */
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| 40 | if (unicode_status != UNICODE_ON /* every byte is a new char */
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| 41 | || (c & 0xc0) != 0x80 /* it isn't a 2nd+ byte of a Unicode char */
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| 42 | ) {
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| 43 | column++;
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| 44 | }
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| 45 | }
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| 46 | return column;
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| 47 | }
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| 48 |
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| 49 | /* Note that this function can write NULs, unlike fputs etc. */
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| 50 | static void write2stdout(const void *buf, unsigned size)
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| 51 | {
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| 52 | fwrite(buf, 1, size, stdout);
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| 53 | }
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| 54 |
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| 55 | int fold_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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| 56 | int fold_main(int argc UNUSED_PARAM, char **argv)
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| 57 | {
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| 58 | char *line_out = NULL;
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| 59 | const char *w_opt = "80";
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| 60 | unsigned width;
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| 61 | smallint exitcode = EXIT_SUCCESS;
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| 62 |
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| 63 | init_unicode();
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| 64 |
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| 65 | if (ENABLE_INCLUDE_SUSv2) {
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| 66 | /* Turn any numeric options into -w options. */
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| 67 | int i;
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| 68 | for (i = 1; argv[i]; i++) {
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| 69 | const char *a = argv[i];
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| 70 | if (*a == '-') {
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| 71 | a++;
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| 72 | if (*a == '-' && !a[1]) /* "--" */
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| 73 | break;
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| 74 | if (isdigit(*a))
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| 75 | argv[i] = xasprintf("-w%s", a);
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| 76 | }
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| 77 | }
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| 78 | }
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| 79 |
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| 80 | getopt32(argv, "bsw:", &w_opt);
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| 81 | width = xatou_range(w_opt, 1, 10000);
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| 82 |
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| 83 | argv += optind;
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| 84 | if (!*argv)
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| 85 | *--argv = (char*)"-";
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| 86 |
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| 87 | do {
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| 88 | FILE *istream = fopen_or_warn_stdin(*argv);
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| 89 | int c;
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| 90 | unsigned column = 0; /* Screen column where next char will go */
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| 91 | unsigned offset_out = 0; /* Index in 'line_out' for next char */
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| 92 |
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| 93 | if (istream == NULL) {
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| 94 | exitcode = EXIT_FAILURE;
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| 95 | continue;
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| 96 | }
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| 97 |
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| 98 | while ((c = getc(istream)) != EOF) {
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| 99 | /* We grow line_out in chunks of 0x1000 bytes */
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| 100 | if ((offset_out & 0xfff) == 0) {
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| 101 | line_out = xrealloc(line_out, offset_out + 0x1000);
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| 102 | }
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| 103 | rescan:
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| 104 | line_out[offset_out] = c;
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| 105 | if (c == '\n') {
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| 106 | write2stdout(line_out, offset_out + 1);
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| 107 | column = offset_out = 0;
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| 108 | continue;
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| 109 | }
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| 110 | column = adjust_column(column, c);
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| 111 | if (column <= width || offset_out == 0) {
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| 112 | /* offset_out == 0 case happens
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| 113 | * with small width (say, 1) and tabs.
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| 114 | * The very first tab already goes to column 8,
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| 115 | * but we must not wrap it */
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| 116 | offset_out++;
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| 117 | continue;
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| 118 | }
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| 119 |
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| 120 | /* This character would make the line too long.
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| 121 | * Print the line plus a newline, and make this character
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| 122 | * start the next line */
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| 123 | if (option_mask32 & FLAG_BREAK_SPACES) {
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| 124 | unsigned i;
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| 125 | unsigned logical_end;
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| 126 |
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| 127 | /* Look for the last blank. */
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| 128 | for (logical_end = offset_out - 1; (int)logical_end >= 0; logical_end--) {
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| 129 | if (!isblank(line_out[logical_end]))
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| 130 | continue;
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| 131 |
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| 132 | /* Found a space or tab.
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| 133 | * Output up to and including it, and start a new line */
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| 134 | logical_end++;
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| 135 | /*line_out[logical_end] = '\n'; - NO! this nukes one buffered character */
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| 136 | write2stdout(line_out, logical_end);
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| 137 | putchar('\n');
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| 138 | /* Move the remainder to the beginning of the next line.
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| 139 | * The areas being copied here might overlap. */
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| 140 | memmove(line_out, line_out + logical_end, offset_out - logical_end);
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| 141 | offset_out -= logical_end;
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| 142 | for (column = i = 0; i < offset_out; i++) {
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| 143 | column = adjust_column(column, line_out[i]);
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| 144 | }
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| 145 | goto rescan;
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| 146 | }
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| 147 | /* No blank found, wrap will split the overlong word */
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| 148 | }
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| 149 | /* Output what we accumulated up to now, and start a new line */
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| 150 | line_out[offset_out] = '\n';
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| 151 | write2stdout(line_out, offset_out + 1);
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| 152 | column = offset_out = 0;
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| 153 | goto rescan;
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| 154 | } /* while (not EOF) */
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| 155 |
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| 156 | if (offset_out) {
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| 157 | write2stdout(line_out, offset_out);
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| 158 | }
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| 159 |
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| 160 | if (fclose_if_not_stdin(istream)) {
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| 161 | bb_simple_perror_msg(*argv);
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| 162 | exitcode = EXIT_FAILURE;
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| 163 | }
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| 164 | } while (*++argv);
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| 165 |
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| 166 | fflush_stdout_and_exit(exitcode);
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| 167 | }
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