Contents of /tags/mkinitrd-6_3_3/busybox/coreutils/fold.c
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Wed Dec 15 21:43:57 2010 UTC (13 years, 9 months ago) by niro
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Wed Dec 15 21:43:57 2010 UTC (13 years, 9 months ago) by niro
File MIME type: text/plain
File size: 4374 byte(s)
tagged 'mkinitrd-6_3_3'
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 | } |