1 /* unexpand - convert spaces to tabs
2 Copyright (C) 1989, 1991, 1995 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> */
40 /* Get isblank from GNU libc. */
45 #include <sys/types.h>
49 /* The number of bytes added at a time to the amount of memory
50 allocated for the output line. */
51 #define OUTPUT_BLOCK 256
53 /* The number of bytes added at a time to the amount of memory
54 allocated for the list of tabstops. */
55 #define TABLIST_BLOCK 256
60 /* The name this program was run with. */
63 /* If nonzero, convert blanks even after nonblank characters have been
65 static int convert_entire_line;
67 /* If nonzero, the size of all tab stops. If zero, use `tab_list' instead. */
70 /* Array of the explicit column numbers of the tab stops;
71 after `tab_list' is exhausted, the rest of the line is printed
72 unchanged. The first column is column 0. */
75 /* The index of the first invalid element of `tab_list',
76 where the next element can be added. */
77 static int first_free_tab;
79 /* Null-terminated array of input filenames. */
80 static char **file_list;
82 /* Default for `file_list' if no files are given on the command line. */
83 static char *stdin_argv[] =
88 /* Nonzero if we have ever read standard input. */
89 static int have_read_stdin;
91 /* Status to return to the system. */
92 static int exit_status;
94 /* If nonzero, display usage information and exit. */
97 /* If nonzero, print the version on standard output then exit. */
98 static int show_version;
100 static struct option const longopts[] =
102 {"tabs", required_argument, NULL, 't'},
103 {"all", no_argument, NULL, 'a'},
104 {"help", no_argument, &show_help, 1},
105 {"version", no_argument, &show_version, 1},
109 /* Add tab stop TABVAL to the end of `tab_list', except
110 if TABVAL is -1, do nothing. */
113 add_tabstop (int tabval)
117 if (first_free_tab % TABLIST_BLOCK == 0)
118 tab_list = (int *) xrealloc (tab_list, first_free_tab + TABLIST_BLOCK);
119 tab_list[first_free_tab++] = tabval;
122 /* Add the comma or blank separated list of tabstops STOPS
123 to the list of tabstops. */
126 parse_tabstops (const char *stops)
130 for (; *stops; stops++)
132 if (*stops == ',' || ISBLANK (*stops))
134 add_tabstop (tabval);
137 else if (ISDIGIT (*stops))
141 tabval = tabval * 10 + *stops - '0';
144 error (1, 0, _("tab size contains an invalid character"));
147 add_tabstop (tabval);
150 /* Check that the list of tabstops TABS, with ENTRIES entries,
151 contains only nonzero, ascending values. */
154 validate_tabstops (const int *tabs, int entries)
159 for (i = 0; i < entries; i++)
162 error (1, 0, _("tab size cannot be 0"));
163 if (tabs[i] <= prev_tab)
164 error (1, 0, _("tab sizes must be ascending"));
169 /* Close the old stream pointer FP if it is non-NULL,
170 and return a new one opened to read the next input file.
171 Open a filename of `-' as the standard input.
172 Return NULL if there are no more input files. */
177 static char *prev_file;
184 error (0, errno, "%s", prev_file);
188 clearerr (fp); /* Also clear EOF. */
189 else if (fclose (fp) == EOF)
191 error (0, errno, "%s", prev_file);
196 while ((file = *file_list++) != NULL)
198 if (file[0] == '-' && file[1] == '\0')
204 fp = fopen (file, "r");
210 error (0, errno, "%s", file);
216 /* Change spaces to tabs, writing to stdout.
217 Read each file in `file_list', in order. */
222 FILE *fp; /* Input stream. */
223 int c; /* Each input character. */
224 /* Index in `tab_list' of next tabstop: */
225 int tab_index = 0; /* For calculating width of pending tabs. */
226 int print_tab_index = 0; /* For printing as many tabs as possible. */
227 int column = 0; /* Column on screen of next char. */
228 int next_tab_column; /* Column the next tab stop is on. */
229 int convert = 1; /* If nonzero, perform translations. */
230 int pending = 0; /* Pending columns of blanks. */
232 fp = next_file ((FILE *) NULL);
243 break; /* No more files. */
248 if (c == ' ' && convert)
253 else if (c == '\t' && convert)
257 /* Do not let tab_index == first_free_tab;
258 stop when it is 1 less. */
259 while (tab_index < first_free_tab - 1
260 && column >= tab_list[tab_index])
262 next_tab_column = tab_list[tab_index];
263 if (tab_index < first_free_tab - 1)
265 if (column >= next_tab_column)
267 convert = 0; /* Ran out of tab stops. */
273 next_tab_column = column + tab_size - column % tab_size;
275 pending += next_tab_column - column;
276 column = next_tab_column;
281 /* Flush pending spaces. Print as many tabs as possible,
282 then print the rest as spaces. */
293 /* Do not let tab_index == first_free_tab;
294 stop when it is 1 less. */
295 while (tab_index < first_free_tab - 1
296 && column >= tab_list[tab_index])
298 next_tab_column = tab_list[print_tab_index];
299 if (print_tab_index < first_free_tab - 1)
304 next_tab_column = column + tab_size - column % tab_size;
306 if (next_tab_column - column <= pending)
309 pending -= next_tab_column - column;
310 column = next_tab_column;
334 if (convert_entire_line == 0)
343 tab_index = print_tab_index = 0;
344 column = pending = 0;
355 fprintf (stderr, _("Try `%s --help' for more information.\n"),
360 Usage: %s [OPTION]... [FILE]...\n\
364 Convert spaces in each FILE to tabs, writing to standard output.\n\
365 With no FILE, or when FILE is -, read standard input.\n\
367 -a, --all convert all whitespace, instead of initial whitespace\n\
368 -t, --tabs=NUMBER have tabs NUMBER characters apart instead of 8\n\
369 -t, --tabs=LIST use comma separated list of explicit tab positions\n\
370 --help display this help and exit\n\
371 --version output version information and exit\n\
373 Instead of -t NUMBER or -t LIST, -NUMBER or -LIST may be used.\n\
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);
392 convert_entire_line = 0;
396 while ((c = getopt_long (argc, argv, "at:,0123456789", longopts, (int *) 0))
407 convert_entire_line = 1;
410 convert_entire_line = 1;
411 parse_tabstops (optarg);
414 add_tabstop (tabval);
420 tabval = tabval * 10 + c - '0';
427 printf ("unexpand - %s\n", PACKAGE_VERSION);
434 add_tabstop (tabval);
436 validate_tabstops (tab_list, first_free_tab);
438 if (first_free_tab == 0)
440 else if (first_free_tab == 1)
441 tab_size = tab_list[0];
446 file_list = stdin_argv;
448 file_list = &argv[optind];
452 if (have_read_stdin && fclose (stdin) == EOF)
453 error (1, errno, "-");
454 if (fclose (stdout) == EOF)
455 error (1, errno, _("write error"));