~vcs-imports/busybox/trunk

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
/* vi: set sw=4 ts=4: */
/*
 * fold -- wrap each input line to fit in specified width.
 *
 * Written by David MacKenzie, djm@gnu.ai.mit.edu.
 * Copyright (C) 91, 1995-2002 Free Software Foundation, Inc.
 *
 * Modified for busybox based on coreutils v 5.0
 * Copyright (C) 2003 Glenn McGrath
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
//config:config FOLD
//config:	bool "fold (4.8 kb)"
//config:	default y
//config:	help
//config:	Wrap text to fit a specific width.

//applet:IF_FOLD(APPLET_NOEXEC(fold, fold, BB_DIR_USR_BIN, BB_SUID_DROP, fold))

//kbuild:lib-$(CONFIG_FOLD) += fold.o

//usage:#define fold_trivial_usage
//usage:       "[-bs] [-w WIDTH] [FILE]..."
//usage:#define fold_full_usage "\n\n"
//usage:       "Wrap input lines in FILEs (or stdin), writing to stdout\n"
//usage:     "\n	-b	Count bytes rather than columns"
//usage:     "\n	-s	Break at spaces"
//usage:     "\n	-w	Use WIDTH columns instead of 80"

#include "libbb.h"
#include "unicode.h"

/* This is a NOEXEC applet. Be very careful! */

/* Must match getopt32 call */
#define FLAG_COUNT_BYTES        1
#define FLAG_BREAK_SPACES       2
#define FLAG_WIDTH              4

/* Assuming the current column is COLUMN, return the column that
   printing C will move the cursor to.
   The first column is 0. */
static int adjust_column(unsigned column, char c)
{
	if (option_mask32 & FLAG_COUNT_BYTES)
		return ++column;

	if (c == '\t')
		return column + 8 - column % 8;

	if (c == '\b') {
		if ((int)--column < 0)
			column = 0;
	}
	else if (c == '\r')
		column = 0;
	else { /* just a printable char */
		if (unicode_status != UNICODE_ON /* every byte is a new char */
		 || (c & 0xc0) != 0x80 /* it isn't a 2nd+ byte of a Unicode char */
		) {
			column++;
		}
	}
	return column;
}

/* Note that this function can write NULs, unlike fputs etc. */
static void write2stdout(const void *buf, unsigned size)
{
	fwrite(buf, 1, size, stdout);
}

int fold_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int fold_main(int argc UNUSED_PARAM, char **argv)
{
	char *line_out = NULL;
	const char *w_opt = "80";
	unsigned width;
	exitcode_t exitcode = EXIT_SUCCESS;

	init_unicode();

	if (ENABLE_INCLUDE_SUSv2) {
		/* Turn any numeric options into -w options.  */
		int i;
		for (i = 1; argv[i]; i++) {
			const char *a = argv[i];
			if (*a == '-') {
				a++;
				if (*a == '-' && !a[1]) /* "--" */
					break;
				if (isdigit(*a))
					argv[i] = xasprintf("-w%s", a);
			}
		}
	}

	getopt32(argv, "bsw:", &w_opt);
	width = xatou_range(w_opt, 1, 10000);

	argv += optind;
	if (!*argv)
		*--argv = (char*)"-";

	do {
		FILE *istream = fopen_or_warn_stdin(*argv);
		int c;
		unsigned column = 0;     /* Screen column where next char will go */
		unsigned offset_out = 0; /* Index in 'line_out' for next char */

		if (istream == NULL) {
			exitcode = EXIT_FAILURE;
			continue;
		}

		while ((c = getc(istream)) != EOF) {
			/* We grow line_out in chunks of 0x1000 bytes */
			if ((offset_out & 0xfff) == 0) {
				line_out = xrealloc(line_out, offset_out + 0x1000);
			}
 rescan:
			line_out[offset_out] = c;
			if (c == '\n') {
				write2stdout(line_out, offset_out + 1);
				column = offset_out = 0;
				continue;
			}
			column = adjust_column(column, c);
			if (column <= width || offset_out == 0) {
				/* offset_out == 0 case happens
				 * with small width (say, 1) and tabs.
				 * The very first tab already goes to column 8,
				 * but we must not wrap it */
				offset_out++;
				continue;
			}

			/* This character would make the line too long.
			 * Print the line plus a newline, and make this character
			 * start the next line */
			if (option_mask32 & FLAG_BREAK_SPACES) {
				unsigned i;
				unsigned logical_end;

				/* Look for the last blank. */
				for (logical_end = offset_out - 1; (int)logical_end >= 0; logical_end--) {
					if (!isblank(line_out[logical_end]))
						continue;

					/* Found a space or tab.
					 * Output up to and including it, and start a new line */
					logical_end++;
					/*line_out[logical_end] = '\n'; - NO! this nukes one buffered character */
					write2stdout(line_out, logical_end);
					putchar('\n');
					/* Move the remainder to the beginning of the next line.
					 * The areas being copied here might overlap. */
					memmove(line_out, line_out + logical_end, offset_out - logical_end);
					offset_out -= logical_end;
					for (column = i = 0; i < offset_out; i++) {
						column = adjust_column(column, line_out[i]);
					}
					goto rescan;
				}
				/* No blank found, wrap will split the overlong word */
			}
			/* Output what we accumulated up to now, and start a new line */
			line_out[offset_out] = '\n';
			write2stdout(line_out, offset_out + 1);
			column = offset_out = 0;
			goto rescan;
		} /* while (not EOF) */

		if (offset_out) {
			write2stdout(line_out, offset_out);
		}

		if (fclose_if_not_stdin(istream)) {
			bb_simple_perror_msg(*argv);
			exitcode = EXIT_FAILURE;
		}
	} while (*++argv);

	fflush_stdout_and_exit(exitcode);
}