1 /* expand - convert tabs to spaces
2 Copyright (C) 1989, 1991 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., 675 Mass Ave, Cambridge, MA 02139, USA. */
18 /* By default, convert all tabs to spaces.
19 Preserves backspace characters in the output; they decrement the
20 column count for tab calculations.
21 The default action is equivalent to -8.
24 --tabs=tab1[,tab2[,...]]
26 -tab1[,tab2[,...]] If only one tab stop is given, set the tabs tab1
27 spaces apart instead of the default 8. Otherwise,
28 set the tabs at columns tab1, tab2, etc. (numbered from
29 0); replace any tabs beyond the tabstops given with
32 -i Only convert initial tabs on each line to spaces.
34 David MacKenzie <djm@gnu.ai.mit.edu> */
36 /* Get isblank from GNU libc. */
41 #include <sys/types.h>
44 /* The number of bytes added at a time to the amount of memory
45 allocated for the output line. */
46 #define OUTPUT_BLOCK 256
48 /* The number of bytes added at a time to the amount of memory
49 allocated for the list of tabstops. */
50 #define TABLIST_BLOCK 256
56 static FILE *next_file ();
57 static void add_tabstop ();
58 static void expand ();
59 static void parse_tabstops ();
61 static void validate_tabstops ();
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, each additional tab is replaced
72 by a space. 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 /* The name this program was run with. */
97 static struct option const longopts[] =
99 {"tabs", required_argument, NULL, 't'},
100 {"initial", no_argument, NULL, 'i'},
109 int tabval = -1; /* Value of tabstop being read, or -1. */
110 int c; /* Option character. */
114 convert_entire_line = 1;
117 program_name = argv[0];
119 while ((c = getopt_long (argc, argv, "it:,0123456789", longopts, (int *) 0))
127 convert_entire_line = 0;
130 parse_tabstops (optarg);
133 add_tabstop (tabval);
139 tabval = tabval * 10 + c - '0';
144 add_tabstop (tabval);
146 validate_tabstops (tab_list, first_free_tab);
148 if (first_free_tab == 0)
150 else if (first_free_tab == 1)
151 tab_size = tab_list[0];
156 file_list = stdin_argv;
158 file_list = &argv[optind];
162 if (have_read_stdin && fclose (stdin) == EOF)
163 error (1, errno, "-");
164 if (ferror (stdout) || fclose (stdout) == EOF)
165 error (1, errno, "write error");
170 /* Add the comma or blank separated list of tabstops STOPS
171 to the list of tabstops. */
174 parse_tabstops (stops)
179 for (; *stops; stops++)
181 if (*stops == ',' || ISBLANK (*stops))
183 add_tabstop (tabval);
186 else if (ISDIGIT (*stops))
190 tabval = tabval * 10 + *stops - '0';
193 error (1, 0, "tab size contains an invalid character");
196 add_tabstop (tabval);
199 /* Add tab stop TABVAL to the end of `tab_list', except
200 if TABVAL is -1, do nothing. */
208 if (first_free_tab % TABLIST_BLOCK == 0)
209 tab_list = (int *) xrealloc (tab_list, first_free_tab + TABLIST_BLOCK);
210 tab_list[first_free_tab++] = tabval;
213 /* Check that the list of tabstops TABS, with ENTRIES entries,
214 contains only nonzero, ascending values. */
217 validate_tabstops (tabs, entries)
224 for (i = 0; i < entries; i++)
227 error (1, 0, "tab size cannot be 0");
228 if (tabs[i] <= prev_tab)
229 error (1, 0, "tab sizes must be ascending");
234 /* Change tabs to spaces, writing to stdout.
235 Read each file in `file_list', in order. */
240 FILE *fp; /* Input stream. */
241 int c; /* Each input character. */
242 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
243 int column = 0; /* Column on screen of the next char. */
244 int next_tab_column; /* Column the next tab stop is on. */
245 int convert = 1; /* If nonzero, perform translations. */
247 fp = next_file ((FILE *) NULL);
255 break; /* No more files. */
267 else if (c == '\t' && convert)
271 /* Do not let tab_index == first_free_tab;
272 stop when it is 1 less. */
273 while (tab_index < first_free_tab - 1
274 && column >= tab_list[tab_index])
276 next_tab_column = tab_list[tab_index];
277 if (tab_index < first_free_tab - 1)
279 if (column >= next_tab_column)
280 next_tab_column = column + 1; /* Ran out of tab stops. */
284 next_tab_column = column + tab_size - column % tab_size;
286 while (column < next_tab_column)
304 if (convert_entire_line == 0)
313 /* Close the old stream pointer FP if it is non-NULL,
314 and return a new one opened to read the next input file.
315 Open a filename of `-' as the standard input.
316 Return NULL if there are no more input files. */
322 static char *prev_file;
329 error (0, errno, "%s", prev_file);
333 clearerr (fp); /* Also clear EOF. */
334 else if (fclose (fp) == EOF)
336 error (0, errno, "%s", prev_file);
341 while ((file = *file_list++) != NULL)
343 if (file[0] == '-' && file[1] == '\0')
349 fp = fopen (file, "r");
355 error (0, errno, "%s", file);
365 Usage: %s [-tab1[,tab2[,...]]] [-t tab1[,tab2[,...]]] [-i]\n\
366 [--tabs=tab1[,tab2[,...]]] [--initial] [file...]\n",