1 /* vi: set sw=4 ts=4: */
2 /* fold -- wrap each input line to fit in specified width.
4 Written by David MacKenzie, djm@gnu.ai.mit.edu.
5 Copyright (C) 91, 1995-2002 Free Software Foundation, Inc.
7 Modified for busybox based on coreutils v 5.0
8 Copyright (C) 2003 Glenn McGrath
10 Licensed under GPLv2 or later, see file LICENSE in this source tree.
15 /* Must match getopt32 call */
16 #define FLAG_COUNT_BYTES 1
17 #define FLAG_BREAK_SPACES 2
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)
25 if (option_mask32 & FLAG_COUNT_BYTES)
29 return column + 8 - column % 8;
32 if ((int)--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 */
47 /* Note that this function can write NULs, unlike fputs etc. */
48 static void write2stdout(const void *buf, unsigned size)
50 fwrite(buf, 1, size, stdout);
53 int fold_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
54 int fold_main(int argc UNUSED_PARAM, char **argv)
56 char *line_out = NULL;
57 const char *w_opt = "80";
59 smallint exitcode = EXIT_SUCCESS;
63 if (ENABLE_INCLUDE_SUSv2) {
64 /* Turn any numeric options into -w options. */
66 for (i = 1; argv[i]; i++) {
67 const char *a = argv[i];
70 if (*a == '-' && !a[1]) /* "--" */
73 argv[i] = xasprintf("-w%s", a);
78 getopt32(argv, "bsw:", &w_opt);
79 width = xatou_range(w_opt, 1, 10000);
86 FILE *istream = fopen_or_warn_stdin(*argv);
88 unsigned column = 0; /* Screen column where next char will go */
89 unsigned offset_out = 0; /* Index in 'line_out' for next char */
91 if (istream == NULL) {
92 exitcode = EXIT_FAILURE;
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);
102 line_out[offset_out] = c;
104 write2stdout(line_out, offset_out + 1);
105 column = offset_out = 0;
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 */
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) {
123 unsigned logical_end;
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]))
130 /* Found a space or tab.
131 * Output up to and including it, and start a new line */
133 /*line_out[logical_end] = '\n'; - NO! this nukes one buffered character */
134 write2stdout(line_out, logical_end);
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]);
145 /* No blank found, wrap will split the overlong word */
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;
152 } /* while (not EOF) */
155 write2stdout(line_out, offset_out);
158 if (fclose_if_not_stdin(istream)) {
159 bb_simple_perror_msg(*argv);
160 exitcode = EXIT_FAILURE;
164 fflush_stdout_and_exit(exitcode);