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
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
|
/* unexpand - convert blanks to tabs
Copyright (C) 1989-2017 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* By default, convert only maximal strings of initial blanks and tabs
into tabs.
Preserves backspace characters in the output; they decrement the
column count for tab calculations.
The default action is equivalent to -8.
Options:
--tabs=tab1[,tab2[,...]]
-t tab1[,tab2[,...]]
-tab1[,tab2[,...]] If only one tab stop is given, set the tabs tab1
columns apart instead of the default 8. Otherwise,
set the tabs at columns tab1, tab2, etc. (numbered from
0); preserve any blanks beyond the tab stops given.
--all
-a Use tabs wherever they would replace 2 or more blanks,
not just at the beginnings of lines.
David MacKenzie <djm@gnu.ai.mit.edu> */
#include <config.h>
#include <stdio.h>
#include <getopt.h>
#include <sys/types.h>
#include "system.h"
#include "die.h"
#include "xstrndup.h"
#include "expand-common.h"
/* The official name of this program (e.g., no 'g' prefix). */
#define PROGRAM_NAME "unexpand"
#define AUTHORS proper_name ("David MacKenzie")
/* For long options that have no equivalent short option, use a
non-character as a pseudo short option, starting with CHAR_MAX + 1. */
enum
{
CONVERT_FIRST_ONLY_OPTION = CHAR_MAX + 1
};
static struct option const longopts[] =
{
{"tabs", required_argument, NULL, 't'},
{"all", no_argument, NULL, 'a'},
{"first-only", no_argument, NULL, CONVERT_FIRST_ONLY_OPTION},
{GETOPT_HELP_OPTION_DECL},
{GETOPT_VERSION_OPTION_DECL},
{NULL, 0, NULL, 0}
};
void
usage (int status)
{
if (status != EXIT_SUCCESS)
emit_try_help ();
else
{
printf (_("\
Usage: %s [OPTION]... [FILE]...\n\
"),
program_name);
fputs (_("\
Convert blanks in each FILE to tabs, writing to standard output.\n\
"), stdout);
emit_stdin_note ();
emit_mandatory_arg_note ();
fputs (_("\
-a, --all convert all blanks, instead of just initial blanks\n\
--first-only convert only leading sequences of blanks (overrides -a)\n\
-t, --tabs=N have tabs N characters apart instead of 8 (enables -a)\n\
-t, --tabs=LIST use comma separated LIST of tab positions (enables -a)\n\
"), stdout);
fputs (HELP_OPTION_DESCRIPTION, stdout);
fputs (VERSION_OPTION_DESCRIPTION, stdout);
emit_ancillary_info (PROGRAM_NAME);
}
exit (status);
}
/* Change blanks to tabs, writing to stdout.
Read each file in 'file_list', in order. */
static void
unexpand (void)
{
/* Input stream. */
FILE *fp = next_file (NULL);
/* The array of pending blanks. In non-POSIX locales, blanks can
include characters other than spaces, so the blanks must be
stored, not merely counted. */
char *pending_blank;
if (!fp)
return;
/* The worst case is a non-blank character, then one blank, then a
tab stop, then MAX_COLUMN_WIDTH - 1 blanks, then a non-blank; so
allocate MAX_COLUMN_WIDTH bytes to store the blanks. */
pending_blank = xmalloc (max_column_width);
while (true)
{
/* Input character, or EOF. */
int c;
/* If true, perform translations. */
bool convert = true;
/* The following variables have valid values only when CONVERT
is true: */
/* Column of next input character. */
uintmax_t column = 0;
/* Column the next input tab stop is on. */
uintmax_t next_tab_column = 0;
/* Index in TAB_LIST of next tab stop to examine. */
size_t tab_index = 0;
/* If true, the first pending blank came just before a tab stop. */
bool one_blank_before_tab_stop = false;
/* If true, the previous input character was a blank. This is
initially true, since initial strings of blanks are treated
as if the line was preceded by a blank. */
bool prev_blank = true;
/* Number of pending columns of blanks. */
size_t pending = 0;
/* Convert a line of text. */
do
{
while ((c = getc (fp)) < 0 && (fp = next_file (fp)))
continue;
if (convert)
{
bool blank = !! isblank (c);
if (blank)
{
bool last_tab IF_LINT (=0);
next_tab_column = get_next_tab_column (column, &tab_index,
&last_tab);
if (last_tab)
convert = false;
if (convert)
{
if (next_tab_column < column)
die (EXIT_FAILURE, 0, _("input line is too long"));
if (c == '\t')
{
column = next_tab_column;
if (pending)
pending_blank[0] = '\t';
}
else
{
column++;
if (! (prev_blank && column == next_tab_column))
{
/* It is not yet known whether the pending blanks
will be replaced by tabs. */
if (column == next_tab_column)
one_blank_before_tab_stop = true;
pending_blank[pending++] = c;
prev_blank = true;
continue;
}
/* Replace the pending blanks by a tab or two. */
pending_blank[0] = c = '\t';
}
/* Discard pending blanks, unless it was a single
blank just before the previous tab stop. */
pending = one_blank_before_tab_stop;
}
}
else if (c == '\b')
{
/* Go back one column, and force recalculation of the
next tab stop. */
column -= !!column;
next_tab_column = column;
tab_index -= !!tab_index;
}
else
{
column++;
if (!column)
die (EXIT_FAILURE, 0, _("input line is too long"));
}
if (pending)
{
if (pending > 1 && one_blank_before_tab_stop)
pending_blank[0] = '\t';
if (fwrite (pending_blank, 1, pending, stdout) != pending)
die (EXIT_FAILURE, errno, _("write error"));
pending = 0;
one_blank_before_tab_stop = false;
}
prev_blank = blank;
convert &= convert_entire_line || blank;
}
if (c < 0)
{
free (pending_blank);
return;
}
if (putchar (c) < 0)
die (EXIT_FAILURE, errno, _("write error"));
}
while (c != '\n');
}
}
int
main (int argc, char **argv)
{
bool have_tabval = false;
uintmax_t tabval IF_LINT ( = 0);
int c;
/* If true, cancel the effect of any -a (explicit or implicit in -t),
so that only leading blanks will be considered. */
bool convert_first_only = false;
initialize_main (&argc, &argv);
set_program_name (argv[0]);
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEDIR);
textdomain (PACKAGE);
atexit (close_stdout);
while ((c = getopt_long (argc, argv, ",0123456789at:", longopts, NULL))
!= -1)
{
switch (c)
{
case '?':
usage (EXIT_FAILURE);
case 'a':
convert_entire_line = true;
break;
case 't':
convert_entire_line = true;
parse_tab_stops (optarg);
break;
case CONVERT_FIRST_ONLY_OPTION:
convert_first_only = true;
break;
case ',':
if (have_tabval)
add_tab_stop (tabval);
have_tabval = false;
break;
case_GETOPT_HELP_CHAR;
case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
default:
if (!have_tabval)
{
tabval = 0;
have_tabval = true;
}
if (!DECIMAL_DIGIT_ACCUMULATE (tabval, c - '0', uintmax_t))
die (EXIT_FAILURE, 0, _("tab stop value is too large"));
break;
}
}
if (convert_first_only)
convert_entire_line = false;
if (have_tabval)
add_tab_stop (tabval);
finalize_tab_stops ();
set_file_list ( (optind < argc) ? &argv[optind] : NULL);
unexpand ();
cleanup_file_list_stdin ();
return exit_status;
}
|