1 /* expand - convert tabs to spaces
2 Copyright (C) 89, 91, 1995-2006, 2008-2009 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17 /* By default, convert all tabs to spaces.
18 Preserves backspace characters in the output; they decrement the
19 column count for tab calculations.
20 The default action is equivalent to -8.
23 --tabs=tab1[,tab2[,...]]
25 -tab1[,tab2[,...]] If only one tab stop is given, set the tabs tab1
26 columns apart instead of the default 8. Otherwise,
27 set the tabs at columns tab1, tab2, etc. (numbered from
28 0); replace any tabs beyond the tab stops given with
31 -i Only convert initial tabs on each line to spaces.
33 David MacKenzie <djm@gnu.ai.mit.edu> */
39 #include <sys/types.h>
45 /* The official name of this program (e.g., no `g' prefix). */
46 #define PROGRAM_NAME "expand"
48 #define AUTHORS proper_name ("David MacKenzie")
50 /* If true, convert blanks even after nonblank characters have been
52 static bool convert_entire_line
;
54 /* If nonzero, the size of all tab stops. If zero, use `tab_list' instead. */
55 static uintmax_t tab_size
;
57 /* Array of the explicit column numbers of the tab stops;
58 after `tab_list' is exhausted, each additional tab is replaced
59 by a space. The first column is column 0. */
60 static uintmax_t *tab_list
;
62 /* The number of allocated entries in `tab_list'. */
63 static size_t n_tabs_allocated
;
65 /* The index of the first invalid element of `tab_list',
66 where the next element can be added. */
67 static size_t first_free_tab
;
69 /* Null-terminated array of input filenames. */
70 static char **file_list
;
72 /* Default for `file_list' if no files are given on the command line. */
73 static char *stdin_argv
[] =
78 /* True if we have ever read standard input. */
79 static bool have_read_stdin
;
81 /* The desired exit status. */
82 static int exit_status
;
84 static char const shortopts
[] = "it:0::1::2::3::4::5::6::7::8::9::";
86 static struct option
const longopts
[] =
88 {"tabs", required_argument
, NULL
, 't'},
89 {"initial", no_argument
, NULL
, 'i'},
90 {GETOPT_HELP_OPTION_DECL
},
91 {GETOPT_VERSION_OPTION_DECL
},
98 if (status
!= EXIT_SUCCESS
)
99 fprintf (stderr
, _("Try `%s --help' for more information.\n"),
104 Usage: %s [OPTION]... [FILE]...\n\
108 Convert tabs in each FILE to spaces, writing to standard output.\n\
109 With no FILE, or when FILE is -, read standard input.\n\
113 Mandatory arguments to long options are mandatory for short options too.\n\
116 -i, --initial do not convert tabs after non blanks\n\
117 -t, --tabs=NUMBER have tabs NUMBER characters apart, not 8\n\
120 -t, --tabs=LIST use comma separated list of explicit tab positions\n\
122 fputs (HELP_OPTION_DESCRIPTION
, stdout
);
123 fputs (VERSION_OPTION_DESCRIPTION
, stdout
);
124 emit_bug_reporting_address ();
129 /* Add tab stop TABVAL to the end of `tab_list'. */
132 add_tab_stop (uintmax_t tabval
)
134 if (first_free_tab
== n_tabs_allocated
)
135 tab_list
= X2NREALLOC (tab_list
, &n_tabs_allocated
);
136 tab_list
[first_free_tab
++] = tabval
;
139 /* Add the comma or blank separated list of tab stops STOPS
140 to the list of tab stops. */
143 parse_tab_stops (char const *stops
)
145 bool have_tabval
= false;
146 uintmax_t tabval
IF_LINT (= 0);
147 char const *num_start
IF_LINT (= NULL
);
150 for (; *stops
; stops
++)
152 if (*stops
== ',' || isblank (to_uchar (*stops
)))
155 add_tab_stop (tabval
);
158 else if (ISDIGIT (*stops
))
167 /* Detect overflow. */
168 if (!DECIMAL_DIGIT_ACCUMULATE (tabval
, *stops
- '0', uintmax_t))
170 size_t len
= strspn (num_start
, "0123456789");
171 char *bad_num
= xstrndup (num_start
, len
);
172 error (0, 0, _("tab stop is too large %s"), quote (bad_num
));
175 stops
= num_start
+ len
- 1;
180 error (0, 0, _("tab size contains invalid character(s): %s"),
191 add_tab_stop (tabval
);
194 /* Check that the list of tab stops TABS, with ENTRIES entries,
195 contains only nonzero, ascending values. */
198 validate_tab_stops (uintmax_t const *tabs
, size_t entries
)
200 uintmax_t prev_tab
= 0;
203 for (i
= 0; i
< entries
; i
++)
206 error (EXIT_FAILURE
, 0, _("tab size cannot be 0"));
207 if (tabs
[i
] <= prev_tab
)
208 error (EXIT_FAILURE
, 0, _("tab sizes must be ascending"));
213 /* Close the old stream pointer FP if it is non-NULL,
214 and return a new one opened to read the next input file.
215 Open a filename of `-' as the standard input.
216 Return NULL if there are no more input files. */
221 static char *prev_file
;
228 error (0, errno
, "%s", prev_file
);
229 exit_status
= EXIT_FAILURE
;
231 if (STREQ (prev_file
, "-"))
232 clearerr (fp
); /* Also clear EOF. */
233 else if (fclose (fp
) != 0)
235 error (0, errno
, "%s", prev_file
);
236 exit_status
= EXIT_FAILURE
;
240 while ((file
= *file_list
++) != NULL
)
242 if (STREQ (file
, "-"))
244 have_read_stdin
= true;
248 fp
= fopen (file
, "r");
254 error (0, errno
, "%s", file
);
255 exit_status
= EXIT_FAILURE
;
260 /* Change tabs to spaces, writing to stdout.
261 Read each file in `file_list', in order. */
267 FILE *fp
= next_file (NULL
);
274 /* Input character, or EOF. */
277 /* If true, perform translations. */
281 /* The following variables have valid values only when CONVERT
284 /* Column of next input character. */
285 uintmax_t column
= 0;
287 /* Index in TAB_LIST of next tab stop to examine. */
288 size_t tab_index
= 0;
291 /* Convert a line of text. */
295 while ((c
= getc (fp
)) < 0 && (fp
= next_file (fp
)))
302 /* Column the next input tab stop is on. */
303 uintmax_t next_tab_column
;
306 next_tab_column
= column
+ (tab_size
- column
% tab_size
);
309 if (tab_index
== first_free_tab
)
311 next_tab_column
= column
+ 1;
316 uintmax_t tab
= tab_list
[tab_index
++];
319 next_tab_column
= tab
;
324 if (next_tab_column
< column
)
325 error (EXIT_FAILURE
, 0, _("input line is too long"));
327 while (++column
< next_tab_column
)
328 if (putchar (' ') < 0)
329 error (EXIT_FAILURE
, errno
, _("write error"));
335 /* Go back one column, and force recalculation of the
338 tab_index
-= !!tab_index
;
344 error (EXIT_FAILURE
, 0, _("input line is too long"));
347 convert
&= convert_entire_line
| !! isblank (c
);
354 error (EXIT_FAILURE
, errno
, _("write error"));
361 main (int argc
, char **argv
)
365 initialize_main (&argc
, &argv
);
366 set_program_name (argv
[0]);
367 setlocale (LC_ALL
, "");
368 bindtextdomain (PACKAGE
, LOCALEDIR
);
369 textdomain (PACKAGE
);
371 atexit (close_stdout
);
373 have_read_stdin
= false;
374 exit_status
= EXIT_SUCCESS
;
375 convert_entire_line
= true;
379 while ((c
= getopt_long (argc
, argv
, shortopts
, longopts
, NULL
)) != -1)
384 convert_entire_line
= false;
388 parse_tab_stops (optarg
);
391 case '0': case '1': case '2': case '3': case '4':
392 case '5': case '6': case '7': case '8': case '9':
394 parse_tab_stops (optarg
- 1);
400 parse_tab_stops (tab_stop
);
404 case_GETOPT_HELP_CHAR
;
406 case_GETOPT_VERSION_CHAR (PROGRAM_NAME
, AUTHORS
);
409 usage (EXIT_FAILURE
);
413 validate_tab_stops (tab_list
, first_free_tab
);
415 if (first_free_tab
== 0)
417 else if (first_free_tab
== 1)
418 tab_size
= tab_list
[0];
422 file_list
= (optind
< argc
? &argv
[optind
] : stdin_argv
);
426 if (have_read_stdin
&& fclose (stdin
) != 0)
427 error (EXIT_FAILURE
, errno
, "-");