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1/* expand - convert tabs to spaces
2 * unexpand - convert spaces to tabs
3 *
4 * Copyright (C) 89, 91, 1995-2006 Free Software Foundation, Inc.
5 *
6 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
7 *
8 * David MacKenzie <djm@gnu.ai.mit.edu>
9 *
10 * Options for expand:
11 * -t num --tabs=NUM Convert tabs to num spaces (default 8 spaces).
12 * -i --initial Only convert initial tabs on each line to spaces.
13 *
14 * Options for unexpand:
15 * -a --all Convert all blanks, instead of just initial blanks.
16 * -f --first-only Convert only leading sequences of blanks (default).
17 * -t num --tabs=NUM Have tabs num characters apart instead of 8.
18 *
19 * Busybox version (C) 2007 by Tito Ragusa <farmatito@tiscali.it>
20 *
21 * Caveat: this versions of expand and unexpand don't accept tab lists.
22 */
23//config:config EXPAND
24//config: bool "expand"
25//config: default y
26//config: help
27//config: By default, convert all tabs to spaces.
28//config:
29//config:config FEATURE_EXPAND_LONG_OPTIONS
30//config: bool "Enable long options"
31//config: default y
32//config: depends on EXPAND && LONG_OPTS
33//config: help
34//config: Support long options for the expand applet.
35//config:
36//config:config UNEXPAND
37//config: bool "unexpand"
38//config: default y
39//config: help
40//config: By default, convert only leading sequences of blanks to tabs.
41//config:
42//config:config FEATURE_UNEXPAND_LONG_OPTIONS
43//config: bool "Enable long options"
44//config: default y
45//config: depends on UNEXPAND && LONG_OPTS
46//config: help
47//config: Support long options for the unexpand applet.
48
49//applet:IF_EXPAND(APPLET(expand, BB_DIR_USR_BIN, BB_SUID_DROP))
50//applet:IF_UNEXPAND(APPLET_ODDNAME(unexpand, expand, BB_DIR_USR_BIN, BB_SUID_DROP, unexpand))
51
52//kbuild:lib-$(CONFIG_EXPAND) += expand.o
53//kbuild:lib-$(CONFIG_UNEXPAND) += expand.o
54
55//usage:#define expand_trivial_usage
56//usage: "[-i] [-t N] [FILE]..."
57//usage:#define expand_full_usage "\n\n"
58//usage: "Convert tabs to spaces, writing to stdout\n"
59//usage: IF_FEATURE_EXPAND_LONG_OPTIONS(
60//usage: "\n -i,--initial Don't convert tabs after non blanks"
61//usage: "\n -t,--tabs=N Tabstops every N chars"
62//usage: )
63//usage: IF_NOT_FEATURE_EXPAND_LONG_OPTIONS(
64//usage: "\n -i Don't convert tabs after non blanks"
65//usage: "\n -t Tabstops every N chars"
66//usage: )
67
68//usage:#define unexpand_trivial_usage
69//usage: "[-fa][-t N] [FILE]..."
70//usage:#define unexpand_full_usage "\n\n"
71//usage: "Convert spaces to tabs, writing to stdout\n"
72//usage: IF_FEATURE_UNEXPAND_LONG_OPTIONS(
73//usage: "\n -a,--all Convert all blanks"
74//usage: "\n -f,--first-only Convert only leading blanks"
75//usage: "\n -t,--tabs=N Tabstops every N chars"
76//usage: )
77//usage: IF_NOT_FEATURE_UNEXPAND_LONG_OPTIONS(
78//usage: "\n -a Convert all blanks"
79//usage: "\n -f Convert only leading blanks"
80//usage: "\n -t N Tabstops every N chars"
81//usage: )
82
83#include "libbb.h"
84#include "unicode.h"
85
86enum {
87 OPT_INITIAL = 1 << 0,
88 OPT_TABS = 1 << 1,
89 OPT_ALL = 1 << 2,
90};
91
92#if ENABLE_EXPAND
93static void expand(FILE *file, unsigned tab_size, unsigned opt)
94{
95 char *line;
96
97 while ((line = xmalloc_fgets(file)) != NULL) {
98 unsigned char c;
99 char *ptr;
100 char *ptr_strbeg;
101
102 ptr = ptr_strbeg = line;
103 while ((c = *ptr) != '\0') {
104 if ((opt & OPT_INITIAL) && !isblank(c)) {
105 /* not space or tab */
106 break;
107 }
108 if (c == '\t') {
109 unsigned len;
110 *ptr = '\0';
111# if ENABLE_UNICODE_SUPPORT
112 len = unicode_strwidth(ptr_strbeg);
113# else
114 len = ptr - ptr_strbeg;
115# endif
116 len = tab_size - (len % tab_size);
117 /*while (ptr[1] == '\t') { ptr++; len += tab_size; } - can handle many tabs at once */
118 printf("%s%*s", ptr_strbeg, len, "");
119 ptr_strbeg = ptr + 1;
120 }
121 ptr++;
122 }
123 fputs(ptr_strbeg, stdout);
124 free(line);
125 }
126}
127#endif
128
129#if ENABLE_UNEXPAND
130static void unexpand(FILE *file, unsigned tab_size, unsigned opt)
131{
132 char *line;
133
134 while ((line = xmalloc_fgets(file)) != NULL) {
135 char *ptr = line;
136 unsigned column = 0;
137
138 while (*ptr) {
139 unsigned n;
140 unsigned len = 0;
141
142 while (*ptr == ' ') {
143 ptr++;
144 len++;
145 }
146 column += len;
147 if (*ptr == '\t') {
148 column += tab_size - (column % tab_size);
149 ptr++;
150 continue;
151 }
152
153 n = column / tab_size;
154 if (n) {
155 len = column = column % tab_size;
156 while (n--)
157 putchar('\t');
158 }
159
160 if ((opt & OPT_INITIAL) && ptr != line) {
161 printf("%*s%s", len, "", ptr);
162 break;
163 }
164 n = strcspn(ptr, "\t ");
165 printf("%*s%.*s", len, "", n, ptr);
166# if ENABLE_UNICODE_SUPPORT
167 {
168 char c = ptr[n];
169 ptr[n] = '\0';
170 len = unicode_strwidth(ptr);
171 ptr[n] = c;
172 }
173# else
174 len = n;
175# endif
176 ptr += n;
177 column = (column + len) % tab_size;
178 }
179 free(line);
180 }
181}
182#endif
183
184int expand_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
185int expand_main(int argc UNUSED_PARAM, char **argv)
186{
187 /* Default 8 spaces for 1 tab */
188 const char *opt_t = "8";
189 FILE *file;
190 unsigned tab_size;
191 unsigned opt;
192 int exit_status = EXIT_SUCCESS;
193
194#if ENABLE_FEATURE_EXPAND_LONG_OPTIONS
195 static const char expand_longopts[] ALIGN1 =
196 /* name, has_arg, val */
197 "initial\0" No_argument "i"
198 "tabs\0" Required_argument "t"
199 ;
200#endif
201#if ENABLE_FEATURE_UNEXPAND_LONG_OPTIONS
202 static const char unexpand_longopts[] ALIGN1 =
203 /* name, has_arg, val */
204 "first-only\0" No_argument "i"
205 "tabs\0" Required_argument "t"
206 "all\0" No_argument "a"
207 ;
208#endif
209 init_unicode();
210
211 if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e')) {
212 IF_FEATURE_EXPAND_LONG_OPTIONS(applet_long_options = expand_longopts);
213 opt = getopt32(argv, "it:", &opt_t);
214 } else {
215 IF_FEATURE_UNEXPAND_LONG_OPTIONS(applet_long_options = unexpand_longopts);
216 /* -t NUM sets also -a */
217 opt_complementary = "ta";
218 opt = getopt32(argv, "ft:a", &opt_t);
219 /* -f --first-only is the default */
220 if (!(opt & OPT_ALL)) opt |= OPT_INITIAL;
221 }
222 tab_size = xatou_range(opt_t, 1, UINT_MAX);
223
224 argv += optind;
225
226 if (!*argv) {
227 *--argv = (char*)bb_msg_standard_input;
228 }
229 do {
230 file = fopen_or_warn_stdin(*argv);
231 if (!file) {
232 exit_status = EXIT_FAILURE;
233 continue;
234 }
235
236 if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e'))
237 IF_EXPAND(expand(file, tab_size, opt));
238 else
239 IF_UNEXPAND(unexpand(file, tab_size, opt));
240
241 /* Check and close the file */
242 if (fclose_if_not_stdin(file)) {
243 bb_simple_perror_msg(*argv);
244 exit_status = EXIT_FAILURE;
245 }
246 /* If stdin also clear EOF */
247 if (file == stdin)
248 clearerr(file);
249 } while (*++argv);
250
251 /* Now close stdin also */
252 /* (if we didn't read from it, it's a no-op) */
253 if (fclose(stdin))
254 bb_perror_msg_and_die("%s", bb_msg_standard_input);
255
256 fflush_stdout_and_exit(exit_status);
257}
258
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