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 (5.1 kb)"
25 //config: default y
26 //config: help
27 //config: By default, convert all tabs to spaces.
28 //config:
29 //config:config UNEXPAND
30 //config: bool "unexpand (5.3 kb)"
31 //config: default y
32 //config: help
33 //config: By default, convert only leading sequences of blanks to tabs.
34
35 //applet:IF_EXPAND(APPLET(expand, BB_DIR_USR_BIN, BB_SUID_DROP))
36 // APPLET_ODDNAME:name main location suid_type help
37 //applet:IF_UNEXPAND(APPLET_ODDNAME(unexpand, expand, BB_DIR_USR_BIN, BB_SUID_DROP, unexpand))
38
39 //kbuild:lib-$(CONFIG_EXPAND) += expand.o
40 //kbuild:lib-$(CONFIG_UNEXPAND) += expand.o
41
42 //usage:#define expand_trivial_usage
43 //usage: "[-i] [-t N] [FILE]..."
44 //usage:#define expand_full_usage "\n\n"
45 //usage: "Convert tabs to spaces, writing to stdout\n"
46 //usage: "\n -i Don't convert tabs after non blanks"
47 //usage: "\n -t Tabstops every N chars"
48
49 //usage:#define unexpand_trivial_usage
50 //usage: "[-fa][-t N] [FILE]..."
51 //usage:#define unexpand_full_usage "\n\n"
52 //usage: "Convert spaces to tabs, writing to stdout\n"
53 //usage: "\n -a Convert all blanks"
54 //usage: "\n -f Convert only leading blanks"
55 //usage: "\n -t N Tabstops every N chars"
56
57 #include "libbb.h"
58 #include "unicode.h"
59
60 enum {
61 OPT_INITIAL = 1 << 0,
62 OPT_TABS = 1 << 1,
63 OPT_ALL = 1 << 2,
64 };
65
66 //FIXME: does not work properly with input containing NULs
67 //coreutils 8.30 preserves NULs but treats them as chars of width zero:
68 //AB<nul><tab>C will expand <tab> to 6 spaces, not 5.
69
70 #if ENABLE_EXPAND
expand(FILE * file,unsigned tab_size,unsigned opt)71 static void expand(FILE *file, unsigned tab_size, unsigned opt)
72 {
73
74 for (;;) {
75 char *line;
76 char *ptr;
77 char *ptr_strbeg;
78 //commented-out code handles NULs, +90 bytes of code, not tested much
79 // size_t linelen;
80 // unsigned len = 0;
81
82 // linelen = 1024 * 1024;
83 // line = xmalloc_fgets_str_len(file, "\n", &linelen);
84 line = xmalloc_fgets(file); //
85 if (!line)
86 break;
87 ptr = ptr_strbeg = line;
88 for (;;) {
89 unsigned char c = *ptr;
90 if (c == '\0') {
91 // size_t rem = line + linelen - ptr;
92 // if (rem > 0) {
93 //# if ENABLE_UNICODE_SUPPORT
94 // len += unicode_strwidth(ptr_strbeg);
95 //# else
96 // len += ptr - ptr_strbeg;
97 //# endif
98 // printf("%s%c", ptr_strbeg, '\0');
99 // memmove(ptr, ptr + 1, rem + 1);
100 // ptr_strbeg = ptr;
101 // linelen--;
102 // continue;
103 // }
104 break;
105 }
106 if ((opt & OPT_INITIAL) && !isblank(c)) {
107 /* not space or tab */
108 break;
109 }
110 if (c == '\t') {
111 unsigned len = 0; //
112 *ptr = '\0';
113 # if ENABLE_UNICODE_SUPPORT
114 len += unicode_strwidth(ptr_strbeg);
115 # else
116 len += ptr - ptr_strbeg;
117 # endif
118 len = tab_size - (len % tab_size);
119 /*while (ptr[1] == '\t') { ptr++; len += tab_size; } - can handle many tabs at once */
120 printf("%s%*s", ptr_strbeg, len, "");
121 // len = 0;
122 ptr_strbeg = ptr + 1;
123 }
124 ptr++;
125 }
126 fputs_stdout(ptr_strbeg);
127 free(line);
128 }
129 }
130 #endif
131
132 #if ENABLE_UNEXPAND
unexpand(FILE * file,unsigned tab_size,unsigned opt)133 static void unexpand(FILE *file, unsigned tab_size, unsigned opt)
134 {
135 char *line;
136
137 while ((line = xmalloc_fgets(file)) != NULL) {
138 char *ptr = line;
139 unsigned column = 0;
140
141 while (*ptr) {
142 unsigned n;
143 unsigned len = 0;
144
145 while (*ptr == ' ') {
146 ptr++;
147 len++;
148 }
149 column += len;
150 if (*ptr == '\t') {
151 column += tab_size - (column % tab_size);
152 ptr++;
153 continue;
154 }
155
156 n = column / tab_size;
157 if (n) {
158 len = column = column % tab_size;
159 while (n--)
160 putchar('\t');
161 }
162
163 if (!(opt & OPT_ALL) && ptr != line) {
164 printf("%*s%s", len, "", ptr);
165 break;
166 }
167 n = strcspn(ptr, "\t ");
168 printf("%*s%.*s", len, "", n, ptr);
169 # if ENABLE_UNICODE_SUPPORT
170 {
171 char c = ptr[n];
172 ptr[n] = '\0';
173 len = unicode_strwidth(ptr);
174 ptr[n] = c;
175 }
176 # else
177 len = n;
178 # endif
179 ptr += n;
180 column = (column + len) % tab_size;
181 }
182 free(line);
183 }
184 }
185 #endif
186
187 int expand_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
expand_main(int argc UNUSED_PARAM,char ** argv)188 int expand_main(int argc UNUSED_PARAM, char **argv)
189 {
190 /* Default 8 spaces for 1 tab */
191 const char *opt_t = "8";
192 FILE *file;
193 unsigned tab_size;
194 unsigned opt;
195 int exit_status = EXIT_SUCCESS;
196
197 init_unicode();
198
199 if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e')) {
200 opt = getopt32long(argv, "it:",
201 "initial\0" No_argument "i"
202 "tabs\0" Required_argument "t"
203 , &opt_t
204 );
205 } else {
206 opt = getopt32long(argv, "^"
207 "ft:a"
208 "\0"
209 "ta" /* -t NUM sets -a */,
210 "first-only\0" No_argument "f"
211 "tabs\0" Required_argument "t"
212 "all\0" No_argument "a"
213 , &opt_t
214 );
215 /* -t implies -a, but an explicit -f overrides */
216 if (opt & OPT_INITIAL) opt &= ~OPT_ALL;
217 }
218 tab_size = xatou_range(opt_t, 1, UINT_MAX);
219
220 argv += optind;
221
222 if (!*argv) {
223 *--argv = (char*)bb_msg_standard_input;
224 }
225 do {
226 file = fopen_or_warn_stdin(*argv);
227 if (!file) {
228 exit_status = EXIT_FAILURE;
229 continue;
230 }
231
232 if (ENABLE_EXPAND && (!ENABLE_UNEXPAND || applet_name[0] == 'e'))
233 IF_EXPAND(expand(file, tab_size, opt));
234 else
235 IF_UNEXPAND(unexpand(file, tab_size, opt));
236
237 /* Check and close the file */
238 if (fclose_if_not_stdin(file)) {
239 bb_simple_perror_msg(*argv);
240 exit_status = EXIT_FAILURE;
241 }
242 /* If stdin also clear EOF */
243 if (file == stdin)
244 clearerr(file);
245 } while (*++argv);
246
247 /* Now close stdin also */
248 /* (if we didn't read from it, it's a no-op) */
249 if (fclose(stdin))
250 bb_simple_perror_msg_and_die(bb_msg_standard_input);
251
252 fflush_stdout_and_exit(exit_status);
253 }
254