/* unexpand - convert blanks to tabs This is the unexpand utility
Copyright (C) 1989-2018 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 <https://www.gnu.org/licenses/>. */ The GNUv3 license
/* 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> Provides system specific information
#include <stdio.h> Provides standard I/O capability
#include <getopt.h> ...!includes auto-comment...
#include <sys/types.h> Provides system data types
#include "system.h" ...!includes auto-comment...
#include "die.h" ...!includes auto-comment...
#include "xstrndup.h" ...!includes auto-comment...
#include "expand-common.h" ...!includes auto-comment...
/* The official name of this program (e.g., no 'g' prefix). */
#define PROGRAM_NAME "unexpand" Line 48
#define AUTHORS proper_name ("David MacKenzie") Line 50
/* For long options that have no equivalent short option, use a
non-character as a pseudo short option, starting with CHAR_MAX + 1. */
enum Line 56
{
CONVERT_FIRST_ONLY_OPTION = CHAR_MAX + 1 Line 58
}; Block 1
static struct option const longopts[] = Line 61
{
{"tabs", required_argument, NULL, 't'}, Line 63
{"all", no_argument, NULL, 'a'}, Line 64
{"first-only", no_argument, NULL, CONVERT_FIRST_ONLY_OPTION}, Line 65
{GETOPT_HELP_OPTION_DECL}, Line 66
{GETOPT_VERSION_OPTION_DECL}, Line 67
{NULL, 0, NULL, 0} Line 68
}; Block 2
void Line 71
usage (int status) Line 72
{
if (status != EXIT_SUCCESS) Line 74
emit_try_help (); ...!common auto-comment...
else Line 76
{
printf (_("\ Line 78
Usage: %s [OPTION]... [FILE]...\n\ Line 79
"), Line 80
program_name); Line 81
fputs (_("\ Line 82
Convert blanks in each FILE to tabs, writing to standard output.\n\ Line 83
"), stdout); Line 84
emit_stdin_note (); ...!common auto-comment...
emit_mandatory_arg_note (); ...!common auto-comment...
fputs (_("\ Line 89
-a, --all convert all blanks, instead of just initial blanks\n\ Line 90
--first-only convert only leading sequences of blanks (overrides -a)\n\ Line 91
-t, --tabs=N have tabs N characters apart instead of 8 (enables -a)\n\ Line 92
"), stdout); Line 93
emit_tab_list_info (); Line 94
fputs (HELP_OPTION_DESCRIPTION, stdout); Line 95
fputs (VERSION_OPTION_DESCRIPTION, stdout); Line 96
emit_ancillary_info (PROGRAM_NAME); Line 97
}
exit (status); Line 99
} Block 3
/* Change blanks to tabs, writing to stdout.
Read each file in 'file_list', in order. */
static void Line 105
unexpand (void) Line 106
{
/* Input stream. */
FILE *fp = next_file (NULL); Line 109
/* 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; Line 114
if (!fp) Line 116
return; Line 117
/* 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); Line 122
while (true) Line 124
{
/* Input character, or EOF. */
int c; Line 127
/* If true, perform translations. */
bool convert = true; Line 130
/* The following variables have valid values only when CONVERT
is true: */
/* Column of next input character. */
uintmax_t column = 0; Line 137
/* Column the next input tab stop is on. */
uintmax_t next_tab_column = 0; Line 140
/* Index in TAB_LIST of next tab stop to examine. */
size_t tab_index = 0; Line 143
/* If true, the first pending blank came just before a tab stop. */
bool one_blank_before_tab_stop = false; Line 146
/* 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; Line 151
/* Number of pending columns of blanks. */
size_t pending = 0; Line 154
/* Convert a line of text. */
do
{
while ((c = getc (fp)) < 0 && (fp = next_file (fp))) Line 161
continue; Line 162
if (convert) Line 164
{
bool blank = !! isblank (c); Line 166
if (blank) Line 168
{
bool last_tab IF_LINT (=0); Line 170
next_tab_column = get_next_tab_column (column, &tab_index, Line 172
&last_tab); Line 173
if (last_tab) Line 175
convert = false; Line 176
if (convert) Line 178
{
if (next_tab_column < column) Line 180
die (EXIT_FAILURE, 0, _("input line is too long")); Line 181
if (c == '\t') Line 183
{
column = next_tab_column; Line 185
if (pending) Line 187
pending_blank[0] = '\t'; Line 188
}
else Line 190
{
column++; Line 192
if (! (prev_blank && column == next_tab_column)) Line 194
{
/* It is not yet known whether the pending blanks
will be replaced by tabs. */
if (column == next_tab_column) Line 198
one_blank_before_tab_stop = true; Line 199
pending_blank[pending++] = c; Line 200
prev_blank = true; Line 201
continue; Line 202
}
/* Replace the pending blanks by a tab or two. */
pending_blank[0] = c = '\t'; Line 206
}
/* Discard pending blanks, unless it was a single
blank just before the previous tab stop. */
pending = one_blank_before_tab_stop; Line 211
}
}
else if (c == '\b') Line 214
{
/* Go back one column, and force recalculation of the
next tab stop. */
column -= !!column; Line 218
next_tab_column = column; Line 219
tab_index -= !!tab_index; Line 220
}
else Line 222
{
column++; Line 224
if (!column) Line 225
die (EXIT_FAILURE, 0, _("input line is too long")); Line 226
}
if (pending) Line 229
{
if (pending > 1 && one_blank_before_tab_stop) Line 231
pending_blank[0] = '\t'; Line 232
if (fwrite (pending_blank, 1, pending, stdout) != pending) Line 233...!syscalls auto-comment...
die (EXIT_FAILURE, errno, _("write error")); Line 234
pending = 0; Line 235
one_blank_before_tab_stop = false; Line 236
}
prev_blank = blank; Line 239
convert &= convert_entire_line || blank; Line 240
}
if (c < 0) Line 243
{
free (pending_blank); Line 245
return; Line 246
}
if (putchar (c) < 0) Line 249
die (EXIT_FAILURE, errno, _("write error")); Line 250
}
while (c != '\n'); Line 252
}
}
int
main (int argc, char **argv) Line 257
{
bool have_tabval = false; Line 259
uintmax_t tabval IF_LINT ( = 0); Line 260
int c; Line 261
/* 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; Line 265
initialize_main (&argc, &argv); VMS-specific entry point handling wildcard expansion
set_program_name (argv[0]); Retains program name and discards path
setlocale (LC_ALL, ""); Sets up internationalization (i18n)
bindtextdomain (PACKAGE, LOCALEDIR); Assigns i18n directorySets text domain for _() [gettext()] function
textdomain (PACKAGE); Sets text domain for _() [gettext()] function
atexit (close_stdout); Close stdout on exit (see gnulib)
while ((c = getopt_long (argc, argv, ",0123456789at:", longopts, NULL)) Line 275
!= -1) Line 276
{
switch (c) Line 278
{
case '?': Line 280
usage (EXIT_FAILURE); Line 281
case 'a': Line 282
convert_entire_line = true; Line 283
break; Line 284
case 't': Line 285
convert_entire_line = true; Line 286
parse_tab_stops (optarg); Line 287
break; Line 288
case CONVERT_FIRST_ONLY_OPTION: Line 289
convert_first_only = true; Line 290
break; Line 291
case ',': Line 292
if (have_tabval) Line 293
add_tab_stop (tabval); Line 294
have_tabval = false; Line 295
break; Line 296
case_GETOPT_HELP_CHAR; Line 297
case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS); Line 298
default: Line 299
if (!have_tabval) Line 300
{
tabval = 0; Line 302
have_tabval = true; Line 303
}
if (!DECIMAL_DIGIT_ACCUMULATE (tabval, c - '0', uintmax_t)) Line 305
die (EXIT_FAILURE, 0, _("tab stop value is too large")); Line 306
break; Line 307
}
}
if (convert_first_only) Line 311
convert_entire_line = false; Line 312
if (have_tabval) Line 314
add_tab_stop (tabval); Line 315
finalize_tab_stops (); Line 317
set_file_list ( (optind < argc) ? &argv[optind] : NULL); Line 319
unexpand (); Line 321
cleanup_file_list_stdin (); Line 323
return exit_status; Line 325
} Block 5