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@ai.mit.edu> */
39 #define isblank(c) ((c) == ' ' || (c) == '\t')
43 #include <sys/types.h>
47 #define ISDIGIT(c) (isascii ((c)) && isdigit ((c)))
49 #define ISDIGIT(c) (isdigit ((c)))
52 /* The number of bytes added at a time to the amount of memory
53 allocated for the output line. */
54 #define OUTPUT_BLOCK 256
56 /* The number of bytes added at a time to the amount of memory
57 allocated for the list of tabstops. */
58 #define TABLIST_BLOCK 256
64 static FILE *next_file ();
65 static void add_tabstop ();
66 static void expand ();
67 static void parse_tabstops ();
69 static void validate_tabstops ();
71 /* If nonzero, convert blanks even after nonblank characters have been
73 static int convert_entire_line;
75 /* If nonzero, the size of all tab stops. If zero, use `tab_list' instead. */
78 /* Array of the explicit column numbers of the tab stops;
79 after `tab_list' is exhausted, each additional tab is replaced
80 by a space. The first column is column 0. */
83 /* The index of the first invalid element of `tab_list',
84 where the next element can be added. */
85 static int first_free_tab;
87 /* Null-terminated array of input filenames. */
88 static char **file_list;
90 /* Default for `file_list' if no files are given on the command line. */
91 static char *stdin_argv[] =
96 /* Nonzero if we have ever read standard input. */
97 static int have_read_stdin;
99 /* Status to return to the system. */
100 static int exit_status;
102 /* The name this program was run with. */
105 static struct option const longopts[] =
107 {"tabs", 1, NULL, 't'},
108 {"initial", 0, NULL, 'i'},
117 int tabval = -1; /* Value of tabstop being read, or -1. */
118 int c; /* Option character. */
122 convert_entire_line = 1;
125 program_name = argv[0];
127 while ((c = getopt_long (argc, argv, "it:,0123456789", longopts, (int *) 0))
135 convert_entire_line = 0;
138 parse_tabstops (optarg);
141 add_tabstop (tabval);
147 tabval = tabval * 10 + c - '0';
152 add_tabstop (tabval);
154 validate_tabstops (tab_list, first_free_tab);
156 if (first_free_tab == 0)
158 else if (first_free_tab == 1)
159 tab_size = tab_list[0];
164 file_list = stdin_argv;
166 file_list = &argv[optind];
170 if (have_read_stdin && fclose (stdin) == EOF)
171 error (1, errno, "-");
172 if (ferror (stdout) || fclose (stdout) == EOF)
173 error (1, 0, "write error");
178 /* Add the comma or blank separated list of tabstops STOPS
179 to the list of tabstops. */
182 parse_tabstops (stops)
187 for (; *stops; stops++)
189 if (*stops == ',' || isblank (*stops))
191 add_tabstop (tabval);
194 else if (ISDIGIT (*stops))
198 tabval = tabval * 10 + *stops - '0';
201 error (1, 0, "tab size contains an invalid character");
204 add_tabstop (tabval);
207 /* Add tab stop TABVAL to the end of `tab_list', except
208 if TABVAL is -1, do nothing. */
216 if (first_free_tab % TABLIST_BLOCK == 0)
217 tab_list = (int *) xrealloc (tab_list, first_free_tab + TABLIST_BLOCK);
218 tab_list[first_free_tab++] = tabval;
221 /* Check that the list of tabstops TABS, with ENTRIES entries,
222 contains only nonzero, ascending values. */
225 validate_tabstops (tabs, entries)
232 for (i = 0; i < entries; i++)
235 error (1, 0, "tab size cannot be 0");
236 if (tabs[i] <= prev_tab)
237 error (1, 0, "tab sizes must be ascending");
242 /* Change tabs to spaces, writing to stdout.
243 Read each file in `file_list', in order. */
248 FILE *fp; /* Input stream. */
249 int c; /* Each input character. */
250 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
251 int column = 0; /* Column on screen of the next char. */
252 int next_tab_column; /* Column the next tab stop is on. */
253 int convert = 1; /* If nonzero, perform translations. */
255 fp = next_file ((FILE *) NULL);
263 break; /* No more files. */
275 else if (c == '\t' && convert)
279 /* Do not let tab_index == first_free_tab;
280 stop when it is 1 less. */
281 while (tab_index < first_free_tab - 1
282 && column >= tab_list[tab_index])
284 next_tab_column = tab_list[tab_index];
285 if (tab_index < first_free_tab - 1)
287 if (column >= next_tab_column)
288 next_tab_column = column + 1; /* Ran out of tab stops. */
292 next_tab_column = column + tab_size - column % tab_size;
294 while (column < next_tab_column)
312 if (convert_entire_line == 0)
321 /* Close the old stream pointer FP if it is non-NULL,
322 and return a new one opened to read the next input file.
323 Open a filename of `-' as the standard input.
324 Return NULL if there are no more input files. */
330 static char *prev_file;
337 error (0, errno, "%s", prev_file);
341 clearerr (fp); /* Also clear EOF. */
342 else if (fclose (fp) == EOF)
344 error (0, errno, "%s", prev_file);
349 while ((file = *file_list++) != NULL)
351 if (file[0] == '-' && file[1] == '\0')
357 fp = fopen (file, "r");
363 error (0, errno, "%s", file);
373 Usage: %s [-tab1[,tab2[,...]]] [-t tab1[,tab2[,...]]] [-i]\n\
374 [--tabs=tab1[,tab2[,...]]] [--initial] [file...]\n",