1 /* expand - convert tabs to spaces
2 Copyright (C) 89, 91, 1995-2001 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 Foundation,
16 Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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> */
40 #include <sys/types.h>
45 /* The official name of this program (e.g., no `g' prefix). */
46 #define PROGRAM_NAME "expand"
48 #define AUTHORS "David MacKenzie"
50 /* The number of bytes added at a time to the amount of memory
51 allocated for the output line. */
52 #define OUTPUT_BLOCK 256
54 /* The number of bytes added at a time to the amount of memory
55 allocated for the list of tabstops. */
56 #define TABLIST_BLOCK 256
58 /* The name this program was run with. */
61 /* If nonzero, convert blanks even after nonblank characters have been
63 static int convert_entire_line;
65 /* If nonzero, the size of all tab stops. If zero, use `tab_list' instead. */
68 /* Array of the explicit column numbers of the tab stops;
69 after `tab_list' is exhausted, each additional tab is replaced
70 by a space. The first column is column 0. */
73 /* The index of the first invalid element of `tab_list',
74 where the next element can be added. */
75 static int first_free_tab;
77 /* Null-terminated array of input filenames. */
78 static char **file_list;
80 /* Default for `file_list' if no files are given on the command line. */
81 static char *stdin_argv[] =
86 /* Nonzero if we have ever read standard input. */
87 static int have_read_stdin;
89 /* Status to return to the system. */
90 static int exit_status;
92 static struct option const longopts[] =
94 {"tabs", required_argument, NULL, 't'},
95 {"initial", no_argument, NULL, 'i'},
96 {GETOPT_HELP_OPTION_DECL},
97 {GETOPT_VERSION_OPTION_DECL},
105 fprintf (stderr, _("Try `%s --help' for more information.\n"),
110 Usage: %s [OPTION]... [FILE]...\n\
114 Convert tabs in each FILE to spaces, writing to standard output.\n\
115 With no FILE, or when FILE is -, read standard input.\n\
119 Mandatory arguments to long options are mandatory for short options too.\n\
122 -i, --initial do not convert TABs after non whitespace\n\
123 -t, --tabs=NUMBER have tabs NUMBER characters apart, not 8\n\
126 -t, --tabs=LIST use comma separated list of explicit tab positions\n\
128 fputs (HELP_OPTION_DESCRIPTION, stdout);
129 fputs (VERSION_OPTION_DESCRIPTION, stdout);
132 Instead of -t NUMBER or -t LIST, -NUMBER or -LIST may be used.\n\
134 puts (_("\nReport bugs to <bug-textutils@gnu.org>."));
136 exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
139 /* Add tab stop TABVAL to the end of `tab_list', except
140 if TABVAL is -1, do nothing. */
143 add_tabstop (int tabval)
147 if (first_free_tab % TABLIST_BLOCK == 0)
148 tab_list = (int *) xrealloc ((char *) tab_list,
150 + TABLIST_BLOCK * sizeof (tab_list[0])));
151 tab_list[first_free_tab++] = tabval;
154 /* Add the comma or blank separated list of tabstops STOPS
155 to the list of tabstops. */
158 parse_tabstops (char *stops)
162 for (; *stops; stops++)
164 if (*stops == ',' || ISBLANK (*stops))
166 add_tabstop (tabval);
169 else if (ISDIGIT (*stops))
173 tabval = tabval * 10 + *stops - '0';
176 error (EXIT_FAILURE, 0, _("tab size contains an invalid character"));
179 add_tabstop (tabval);
182 /* Check that the list of tabstops TABS, with ENTRIES entries,
183 contains only nonzero, ascending values. */
186 validate_tabstops (int *tabs, int entries)
191 for (i = 0; i < entries; i++)
194 error (EXIT_FAILURE, 0, _("tab size cannot be 0"));
195 if (tabs[i] <= prev_tab)
196 error (EXIT_FAILURE, 0, _("tab sizes must be ascending"));
201 /* Close the old stream pointer FP if it is non-NULL,
202 and return a new one opened to read the next input file.
203 Open a filename of `-' as the standard input.
204 Return NULL if there are no more input files. */
209 static char *prev_file;
216 error (0, errno, "%s", prev_file);
220 clearerr (fp); /* Also clear EOF. */
221 else if (fclose (fp) == EOF)
223 error (0, errno, "%s", prev_file);
228 while ((file = *file_list++) != NULL)
230 if (file[0] == '-' && file[1] == '\0')
236 fp = fopen (file, "r");
242 error (0, errno, "%s", file);
248 /* Change tabs to spaces, writing to stdout.
249 Read each file in `file_list', in order. */
254 FILE *fp; /* Input stream. */
255 int c; /* Each input character. */
256 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
257 int column = 0; /* Column on screen of the next char. */
258 int next_tab_column; /* Column the next tab stop is on. */
259 int convert = 1; /* If nonzero, perform translations. */
261 fp = next_file ((FILE *) NULL);
265 /* Binary I/O will preserve the original EOL style (DOS/Unix) of files. */
266 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
275 break; /* No more files. */
278 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
290 else if (c == '\t' && convert)
294 /* Do not let tab_index == first_free_tab;
295 stop when it is 1 less. */
296 while (tab_index < first_free_tab - 1
297 && column >= tab_list[tab_index])
299 next_tab_column = tab_list[tab_index];
300 if (tab_index < first_free_tab - 1)
302 if (column >= next_tab_column)
303 next_tab_column = column + 1; /* Ran out of tab stops. */
307 next_tab_column = column + tab_size - column % tab_size;
309 while (column < next_tab_column)
327 if (convert_entire_line == 0)
337 main (int argc, char **argv)
339 int tabval = -1; /* Value of tabstop being read, or -1. */
340 int c; /* Option character. */
344 convert_entire_line = 1;
347 program_name = argv[0];
348 setlocale (LC_ALL, "");
349 bindtextdomain (PACKAGE, LOCALEDIR);
350 textdomain (PACKAGE);
352 atexit (close_stdout);
354 while ((c = getopt_long (argc, argv, "it:,0123456789", longopts, NULL)) != -1)
364 convert_entire_line = 0;
367 parse_tabstops (optarg);
370 add_tabstop (tabval);
373 case_GETOPT_HELP_CHAR;
374 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
378 tabval = tabval * 10 + c - '0';
383 add_tabstop (tabval);
385 validate_tabstops (tab_list, first_free_tab);
387 if (first_free_tab == 0)
389 else if (first_free_tab == 1)
390 tab_size = tab_list[0];
395 file_list = stdin_argv;
397 file_list = &argv[optind];
401 if (have_read_stdin && fclose (stdin) == EOF)
402 error (EXIT_FAILURE, errno, "-");
404 exit (exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);