1 /* unexpand - convert spaces to tabs
2 Copyright (C) 89, 91, 1995-1999 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 2, or (at your option)
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, write to the Free Software
16 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
18 /* By default, convert only maximal strings of initial blanks and tabs
20 Preserves backspace characters in the output; they decrement the
21 column count for tab calculations.
22 The default action is equivalent to -8.
25 --tabs=tab1[,tab2[,...]]
27 -tab1[,tab2[,...]] If only one tab stop is given, set the tabs tab1
28 spaces apart instead of the default 8. Otherwise,
29 set the tabs at columns tab1, tab2, etc. (numbered from
30 0); replace any tabs beyond the tabstops given with
33 -a Use tabs wherever they would replace 2 or more spaces,
34 not just at the beginnings of lines.
36 David MacKenzie <djm@gnu.ai.mit.edu> */
42 #include <sys/types.h>
45 #include "long-options.h"
48 /* The official name of this program (e.g., no `g' prefix). */
49 #define PROGRAM_NAME "unexpand"
51 /* The number of bytes added at a time to the amount of memory
52 allocated for the output line. */
53 #define OUTPUT_BLOCK 256
55 /* The number of bytes added at a time to the amount of memory
56 allocated for the list of tabstops. */
57 #define TABLIST_BLOCK 256
59 /* The name this program was run with. */
62 /* If nonzero, convert blanks even after nonblank characters have been
64 static int convert_entire_line;
66 /* If nonzero, the size of all tab stops. If zero, use `tab_list' instead. */
69 /* Array of the explicit column numbers of the tab stops;
70 after `tab_list' is exhausted, the rest of the line is printed
71 unchanged. The first column is column 0. */
74 /* The index of the first invalid element of `tab_list',
75 where the next element can be added. */
76 static int first_free_tab;
78 /* Null-terminated array of input filenames. */
79 static char **file_list;
81 /* Default for `file_list' if no files are given on the command line. */
82 static char *stdin_argv[] =
87 /* Nonzero if we have ever read standard input. */
88 static int have_read_stdin;
90 /* Status to return to the system. */
91 static int exit_status;
93 static struct option const longopts[] =
95 {"tabs", required_argument, NULL, 't'},
96 {"all", no_argument, NULL, 'a'},
100 /* Add tab stop TABVAL to the end of `tab_list', except
101 if TABVAL is -1, do nothing. */
104 add_tabstop (int tabval)
108 if (first_free_tab % TABLIST_BLOCK == 0)
109 tab_list = (int *) xrealloc ((char *) tab_list,
110 first_free_tab + TABLIST_BLOCK);
111 tab_list[first_free_tab++] = tabval;
114 /* Add the comma or blank separated list of tabstops STOPS
115 to the list of tabstops. */
118 parse_tabstops (const char *stops)
122 for (; *stops; stops++)
124 if (*stops == ',' || ISBLANK (*stops))
126 add_tabstop (tabval);
129 else if (ISDIGIT (*stops))
133 tabval = tabval * 10 + *stops - '0';
136 error (EXIT_FAILURE, 0, _("tab size contains an invalid character"));
139 add_tabstop (tabval);
142 /* Check that the list of tabstops TABS, with ENTRIES entries,
143 contains only nonzero, ascending values. */
146 validate_tabstops (const int *tabs, int entries)
151 for (i = 0; i < entries; i++)
154 error (EXIT_FAILURE, 0, _("tab size cannot be 0"));
155 if (tabs[i] <= prev_tab)
156 error (EXIT_FAILURE, 0, _("tab sizes must be ascending"));
161 /* Close the old stream pointer FP if it is non-NULL,
162 and return a new one opened to read the next input file.
163 Open a filename of `-' as the standard input.
164 Return NULL if there are no more input files. */
169 static char *prev_file;
176 error (0, errno, "%s", prev_file);
180 clearerr (fp); /* Also clear EOF. */
181 else if (fclose (fp) == EOF)
183 error (0, errno, "%s", prev_file);
188 while ((file = *file_list++) != NULL)
190 if (file[0] == '-' && file[1] == '\0')
196 fp = fopen (file, "r");
202 error (0, errno, "%s", file);
208 /* Change spaces to tabs, writing to stdout.
209 Read each file in `file_list', in order. */
214 FILE *fp; /* Input stream. */
215 int c; /* Each input character. */
216 /* Index in `tab_list' of next tabstop: */
217 int tab_index = 0; /* For calculating width of pending tabs. */
218 int print_tab_index = 0; /* For printing as many tabs as possible. */
219 int column = 0; /* Column on screen of next char. */
220 int next_tab_column; /* Column the next tab stop is on. */
221 int convert = 1; /* If nonzero, perform translations. */
222 int pending = 0; /* Pending columns of blanks. */
224 fp = next_file ((FILE *) NULL);
228 /* Binary I/O will preserve the original EOL style (DOS/Unix) of files. */
229 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
235 if (c == ' ' && convert)
240 else if (c == '\t' && convert)
244 /* Do not let tab_index == first_free_tab;
245 stop when it is 1 less. */
246 while (tab_index < first_free_tab - 1
247 && column >= tab_list[tab_index])
249 next_tab_column = tab_list[tab_index];
250 if (tab_index < first_free_tab - 1)
252 if (column >= next_tab_column)
254 convert = 0; /* Ran out of tab stops. */
260 next_tab_column = column + tab_size - column % tab_size;
262 pending += next_tab_column - column;
263 column = next_tab_column;
268 /* Flush pending spaces. Print as many tabs as possible,
269 then print the rest as spaces. */
280 /* Do not let print_tab_index == first_free_tab;
281 stop when it is 1 less. */
282 while (print_tab_index < first_free_tab - 1
283 && column >= tab_list[print_tab_index])
285 next_tab_column = tab_list[print_tab_index];
286 if (print_tab_index < first_free_tab - 1)
291 next_tab_column = column + tab_size - column % tab_size;
293 if (next_tab_column - column <= pending)
296 pending -= next_tab_column - column;
297 column = next_tab_column;
315 break; /* No more files. */
318 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
333 if (convert_entire_line == 0)
342 tab_index = print_tab_index = 0;
343 column = pending = 0;
354 fprintf (stderr, _("Try `%s --help' for more information.\n"),
359 Usage: %s [OPTION]... [FILE]...\n\
363 Convert spaces in each FILE to tabs, writing to standard output.\n\
364 With no FILE, or when FILE is -, read standard input.\n\
366 -a, --all convert all whitespace, instead of initial whitespace\n\
367 -t, --tabs=NUMBER have tabs NUMBER characters apart instead of 8\n\
368 -t, --tabs=LIST use comma separated list of explicit tab positions\n\
369 --help display this help and exit\n\
370 --version output version information and exit\n\
372 Instead of -t NUMBER or -t LIST, -NUMBER or -LIST may be used.\n\
374 puts (_("\nReport bugs to <bug-textutils@gnu.org>."));
376 exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
380 main (int argc, char **argv)
382 int tabval = -1; /* Value of tabstop being read, or -1. */
383 int c; /* Option character. */
385 program_name = argv[0];
386 setlocale (LC_ALL, "");
387 bindtextdomain (PACKAGE, LOCALEDIR);
388 textdomain (PACKAGE);
390 parse_long_options (argc, argv, "unexpand", GNU_PACKAGE, VERSION,
391 "David MacKenzie", usage);
395 convert_entire_line = 0;
399 while ((c = getopt_long (argc, argv, "at:,0123456789", longopts, NULL)) != -1)
409 convert_entire_line = 1;
412 convert_entire_line = 1;
413 parse_tabstops (optarg);
416 add_tabstop (tabval);
422 tabval = tabval * 10 + c - '0';
427 add_tabstop (tabval);
429 validate_tabstops (tab_list, first_free_tab);
431 if (first_free_tab == 0)
433 else if (first_free_tab == 1)
434 tab_size = tab_list[0];
437 /* Append a sentinel to the list of tab stop indices. */
438 add_tabstop (INT_MAX);
443 file_list = stdin_argv;
445 file_list = &argv[optind];
449 if (have_read_stdin && fclose (stdin) == EOF)
450 error (EXIT_FAILURE, errno, "-");
451 if (fclose (stdout) == EOF)
452 error (EXIT_FAILURE, errno, _("write error"));
453 exit (exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);