aboutsummaryrefslogtreecommitdiff
path: root/coreutils/expand.c
blob: c5e1de6f576e28f026628367ea2de9f4f52c10d1 (plain)
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
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
/* expand - convert tabs to spaces
 * unexpand - convert spaces to tabs
 *
 * Copyright (C) 89, 91, 1995-2006 Free Software Foundation, Inc.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 *
 * David MacKenzie <djm@gnu.ai.mit.edu>
 *
 * Options for expand:
 * -t num  --tabs NUM      Convert tabs to num spaces (default 8 spaces).
 * -i      --initial       Only convert initial tabs on each line to spaces.
 *
 * Options for unexpand:
 * -a      --all           Convert all blanks, instead of just initial blanks.
 * -f      --first-only    Convert only leading sequences of blanks (default).
 * -t num  --tabs NUM      Have tabs num characters apart instead of 8.
 *
 *  Busybox version (C) 2007 by Tito Ragusa <farmatito@tiscali.it>
 *
 *  Caveat: this versions of expand and unexpand don't accept tab lists.
 */
//config:config EXPAND
//config:	bool "expand (5.1 kb)"
//config:	default y
//config:	help
//config:	By default, convert all tabs to spaces.
//config:
//config:config UNEXPAND
//config:	bool "unexpand (5.3 kb)"
//config:	default y
//config:	help
//config:	By default, convert only leading sequences of blanks to tabs.

//applet:IF_EXPAND(APPLET(expand, BB_DIR_USR_BIN, BB_SUID_DROP))
//                   APPLET_ODDNAME:name      main    location        suid_type     help
//applet:IF_UNEXPAND(APPLET_ODDNAME(unexpand, expand, BB_DIR_USR_BIN, BB_SUID_DROP, unexpand))

//kbuild:lib-$(CONFIG_EXPAND) += expand.o
//kbuild:lib-$(CONFIG_UNEXPAND) += expand.o

//usage:#define expand_trivial_usage
//usage:       "[-i] [-t N] [FILE]..."
//usage:#define expand_full_usage "\n\n"
//usage:       "Convert tabs to spaces, writing to stdout\n"
//usage:     "\n	-i	Don't convert tabs after non blanks"
//usage:     "\n	-t	Tabstops every N chars"

//usage:#define unexpand_trivial_usage
//usage:       "[-fa][-t N] [FILE]..."
//usage:#define unexpand_full_usage "\n\n"
//usage:       "Convert spaces to tabs, writing to stdout\n"
//usage:     "\n	-a	Convert all blanks"
//usage:     "\n	-f	Convert only leading blanks"
//usage:     "\n	-t N	Tabstops every N chars"

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

enum {
	OPT_INITIAL     = 1 << 0,
	OPT_TABS        = 1 << 1,
	OPT_ALL         = 1 << 2,
};

//FIXME: does not work properly with input containing NULs
//coreutils 8.30 preserves NULs but treats them as chars of width zero:
//AB<nul><tab>C will expand <tab> to 6 spaces, not 5.

#if ENABLE_EXPAND
static void expand(FILE *file, unsigned tab_size, unsigned opt)
{

	for (;;) {
		char *line;
		char *ptr;
		char *ptr_strbeg;
//commented-out code handles NULs, +90 bytes of code, not tested much
//		size_t linelen;
//		unsigned len = 0;

//		linelen = 1024 * 1024;
//		line = xmalloc_fgets_str_len(file, "\n", &linelen);
		line = xmalloc_fgets(file); //
		if (!line)
			break;
		ptr = ptr_strbeg = line;
		for (;;) {
			unsigned char c = *ptr;
			if (c == '\0') {
//				size_t rem = line + linelen - ptr;
//				if (rem > 0) {
//# if ENABLE_UNICODE_SUPPORT
//					len += unicode_strwidth(ptr_strbeg);
//# else
//					len += ptr - ptr_strbeg;
//# endif
//					printf("%s%c", ptr_strbeg, '\0');
//					memmove(ptr, ptr + 1, rem + 1);
//					ptr_strbeg = ptr;
//					linelen--;
//					continue;
//				}
				break;
			}
			if ((opt & OPT_INITIAL) && !isblank(c)) {
				/* not space or tab */
				break;
			}
			if (c == '\t') {
				unsigned len = 0; //
				*ptr = '\0';
# if ENABLE_UNICODE_SUPPORT
				len += unicode_strwidth(ptr_strbeg);
# else
				len += ptr - ptr_strbeg;
# endif
				len = tab_size - (len % tab_size);
				/*while (ptr[1] == '\t') { ptr++; len += tab_size; } - can handle many tabs at once */
				printf("%s%*s", ptr_strbeg, len, "");
//				len = 0;
				ptr_strbeg = ptr + 1;
			}
			ptr++;
		}
		fputs_stdout(ptr_strbeg);
		free(line);
	}
}
#endif

#if ENABLE_UNEXPAND
static void unexpand(FILE *file, unsigned tab_size, unsigned opt)
{
	char *line;

	while ((line = xmalloc_fgets(file)) != NULL) {
		char *ptr = line;
		unsigned column = 0;

		while (*ptr) {
			unsigned n;
			unsigned len = 0;

			while (*ptr == ' ') {
				ptr++;
				len++;
			}
			column += len;
			if (*ptr == '\t') {
				column += tab_size - (column % tab_size);
				ptr++;
				continue;
			}

			n = column / tab_size;
			if (n) {
				len = column = column % tab_size;
				while (n--)
					putchar('\t');
			}

			if (!(opt & OPT_ALL) && ptr != line) {
				printf("%*s%s", len, "", ptr);
				break;
			}
			n = strcspn(ptr, "\t ");
			printf("%*s%.*s", len, "", n, ptr);
# if ENABLE_UNICODE_SUPPORT
			{
				char c = ptr[n];
				ptr[n] = '\0';
				len = unicode_strwidth(ptr);
				ptr[n] = c;
			}
# else
			len = n;
# endif
			ptr += n;
			column = (column + len) % tab_size;
		}
		free(line);
	}
}
#endif

int expand_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int expand_main(int argc UNUSED_PARAM, char **argv)
{
	/* Default 8 spaces for 1 tab */
	const char *opt_t = "8";
	FILE *file;
	unsigned tab_size;
	unsigned opt;
	int exit_status = EXIT_SUCCESS;

	init_unicode();

	if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e')) {
		opt = getopt32long(argv, "it:",
				"initial\0"          No_argument       "i"
				"tabs\0"             Required_argument "t"
				, &opt_t
		);
	} else {
		opt = getopt32long(argv, "^"
				"ft:a"
				"\0"
				"ta" /* -t NUM sets -a */,
				"first-only\0"       No_argument       "f"
				"tabs\0"             Required_argument "t"
				"all\0"              No_argument       "a"
				, &opt_t
		);
		/* -t implies -a, but an explicit -f overrides */
		if (opt & OPT_INITIAL) opt &= ~OPT_ALL;
	}
	tab_size = xatou_range(opt_t, 1, UINT_MAX);

	argv += optind;

	if (!*argv) {
		*--argv = (char*)bb_msg_standard_input;
	}
	do {
		file = fopen_or_warn_stdin(*argv);
		if (!file) {
			exit_status = EXIT_FAILURE;
			continue;
		}

		if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e'))
			IF_EXPAND(expand(file, tab_size, opt));
		else
			IF_UNEXPAND(unexpand(file, tab_size, opt));

		/* Check and close the file */
		if (fclose_if_not_stdin(file)) {
			bb_simple_perror_msg(*argv);
			exit_status = EXIT_FAILURE;
		}
		/* If stdin also clear EOF */
		if (file == stdin)
			clearerr(file);
	} while (*++argv);

	/* Now close stdin also */
	/* (if we didn't read from it, it's a no-op) */
	if (fclose(stdin))
		bb_simple_perror_msg_and_die(bb_msg_standard_input);

	fflush_stdout_and_exit(exit_status);
}