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> */
37 #if defined (CONFIG_BROKETS)
38 /* We use <config.h> instead of "config.h" so that a compilation
39 using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h
40 (which it would do because it found this file in $srcdir). */
47 /* Get isblank from GNU libc. */
52 #include <sys/types.h>
56 /* The number of bytes added at a time to the amount of memory
57 allocated for the output line. */
58 #define OUTPUT_BLOCK 256
60 /* The number of bytes added at a time to the amount of memory
61 allocated for the list of tabstops. */
62 #define TABLIST_BLOCK 256
68 static FILE *next_file ();
69 static void add_tabstop ();
70 static void expand ();
71 static void parse_tabstops ();
73 static void validate_tabstops ();
75 /* The name this program was run with. */
78 /* If nonzero, convert blanks even after nonblank characters have been
80 static int convert_entire_line;
82 /* If nonzero, the size of all tab stops. If zero, use `tab_list' instead. */
85 /* Array of the explicit column numbers of the tab stops;
86 after `tab_list' is exhausted, each additional tab is replaced
87 by a space. The first column is column 0. */
90 /* The index of the first invalid element of `tab_list',
91 where the next element can be added. */
92 static int first_free_tab;
94 /* Null-terminated array of input filenames. */
95 static char **file_list;
97 /* Default for `file_list' if no files are given on the command line. */
98 static char *stdin_argv[] =
103 /* Nonzero if we have ever read standard input. */
104 static int have_read_stdin;
106 /* Status to return to the system. */
107 static int exit_status;
109 /* If non-zero, display usage information and exit. */
110 static int show_help;
112 /* If non-zero, print the version on standard output then exit. */
113 static int show_version;
115 static struct option const longopts[] =
117 {"tabs", required_argument, NULL, 't'},
118 {"initial", no_argument, NULL, 'i'},
119 {"help", no_argument, &show_help, 1},
120 {"version", no_argument, &show_version, 1},
129 int tabval = -1; /* Value of tabstop being read, or -1. */
130 int c; /* Option character. */
134 convert_entire_line = 1;
137 program_name = argv[0];
139 while ((c = getopt_long (argc, argv, "it:,0123456789", longopts, (int *) 0))
150 convert_entire_line = 0;
153 parse_tabstops (optarg);
156 add_tabstop (tabval);
162 tabval = tabval * 10 + c - '0';
169 printf ("%s\n", version_string);
176 add_tabstop (tabval);
178 validate_tabstops (tab_list, first_free_tab);
180 if (first_free_tab == 0)
182 else if (first_free_tab == 1)
183 tab_size = tab_list[0];
188 file_list = stdin_argv;
190 file_list = &argv[optind];
194 if (have_read_stdin && fclose (stdin) == EOF)
195 error (1, errno, "-");
196 if (ferror (stdout) || fclose (stdout) == EOF)
197 error (1, errno, "write error");
202 /* Add the comma or blank separated list of tabstops STOPS
203 to the list of tabstops. */
206 parse_tabstops (stops)
211 for (; *stops; stops++)
213 if (*stops == ',' || ISBLANK (*stops))
215 add_tabstop (tabval);
218 else if (ISDIGIT (*stops))
222 tabval = tabval * 10 + *stops - '0';
225 error (1, 0, "tab size contains an invalid character");
228 add_tabstop (tabval);
231 /* Add tab stop TABVAL to the end of `tab_list', except
232 if TABVAL is -1, do nothing. */
240 if (first_free_tab % TABLIST_BLOCK == 0)
241 tab_list = (int *) xrealloc (tab_list, first_free_tab + TABLIST_BLOCK);
242 tab_list[first_free_tab++] = tabval;
245 /* Check that the list of tabstops TABS, with ENTRIES entries,
246 contains only nonzero, ascending values. */
249 validate_tabstops (tabs, entries)
256 for (i = 0; i < entries; i++)
259 error (1, 0, "tab size cannot be 0");
260 if (tabs[i] <= prev_tab)
261 error (1, 0, "tab sizes must be ascending");
266 /* Change tabs to spaces, writing to stdout.
267 Read each file in `file_list', in order. */
272 FILE *fp; /* Input stream. */
273 int c; /* Each input character. */
274 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
275 int column = 0; /* Column on screen of the next char. */
276 int next_tab_column; /* Column the next tab stop is on. */
277 int convert = 1; /* If nonzero, perform translations. */
279 fp = next_file ((FILE *) NULL);
287 break; /* No more files. */
299 else if (c == '\t' && convert)
303 /* Do not let tab_index == first_free_tab;
304 stop when it is 1 less. */
305 while (tab_index < first_free_tab - 1
306 && column >= tab_list[tab_index])
308 next_tab_column = tab_list[tab_index];
309 if (tab_index < first_free_tab - 1)
311 if (column >= next_tab_column)
312 next_tab_column = column + 1; /* Ran out of tab stops. */
316 next_tab_column = column + tab_size - column % tab_size;
318 while (column < next_tab_column)
336 if (convert_entire_line == 0)
345 /* Close the old stream pointer FP if it is non-NULL,
346 and return a new one opened to read the next input file.
347 Open a filename of `-' as the standard input.
348 Return NULL if there are no more input files. */
354 static char *prev_file;
361 error (0, errno, "%s", prev_file);
365 clearerr (fp); /* Also clear EOF. */
366 else if (fclose (fp) == EOF)
368 error (0, errno, "%s", prev_file);
373 while ((file = *file_list++) != NULL)
375 if (file[0] == '-' && file[1] == '\0')
381 fp = fopen (file, "r");
387 error (0, errno, "%s", file);
398 fprintf (stderr, "Try `%s --help' for more information.\n",
403 Usage: %s [OPTION]... [FILE]...\n\
408 -i, --initial do not convert TABs after non whitespace\n\
409 -t, --tabs NUMBER have tabs NUMBER characters apart, not 8\n\
410 -t, --tabs LIST use comma separated list of explicit tab positions\n\
411 --help display this help and exit\n\
412 --version output version information and exit\n\
414 Instead of -t NUMBER or -t LIST, -NUMBER or -LIST may be used. With\n\
415 no FILE, or when FILE is -, read standard input.\n\