1 /* expand - convert tabs to spaces
2 Copyright (C) 89, 91, 1995-2002 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 char const shortopts[] = "it:"
93 #if POSIX2_VERSION < 200112
98 static struct option const longopts[] =
100 {"tabs", required_argument, NULL, 't'},
101 {"initial", no_argument, NULL, 'i'},
102 {GETOPT_HELP_OPTION_DECL},
103 {GETOPT_VERSION_OPTION_DECL},
111 fprintf (stderr, _("Try `%s --help' for more information.\n"),
116 Usage: %s [OPTION]... [FILE]...\n\
120 Convert tabs in each FILE to spaces, writing to standard output.\n\
121 With no FILE, or when FILE is -, read standard input.\n\
125 Mandatory arguments to long options are mandatory for short options too.\n\
128 -i, --initial do not convert TABs after non whitespace\n\
129 -t, --tabs=NUMBER have tabs NUMBER characters apart, not 8\n\
132 -t, --tabs=LIST use comma separated list of explicit tab positions\n\
134 fputs (HELP_OPTION_DESCRIPTION, stdout);
135 fputs (VERSION_OPTION_DESCRIPTION, stdout);
136 if (POSIX2_VERSION < 200112)
139 (obsolete) Instead of -t NUMBER or -t LIST, -NUMBER or -LIST may be used.\n\
141 puts (_("\nReport bugs to <bug-textutils@gnu.org>."));
143 exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
146 /* Add tab stop TABVAL to the end of `tab_list', except
147 if TABVAL is -1, do nothing. */
150 add_tabstop (int tabval)
154 if (first_free_tab % TABLIST_BLOCK == 0)
155 tab_list = (int *) xrealloc ((char *) tab_list,
157 + TABLIST_BLOCK * sizeof (tab_list[0])));
158 tab_list[first_free_tab++] = tabval;
161 /* Add the comma or blank separated list of tabstops STOPS
162 to the list of tabstops. */
165 parse_tabstops (char *stops)
169 for (; *stops; stops++)
171 if (*stops == ',' || ISBLANK (*stops))
173 add_tabstop (tabval);
176 else if (ISDIGIT (*stops))
180 tabval = tabval * 10 + *stops - '0';
183 error (EXIT_FAILURE, 0, _("tab size contains an invalid character"));
186 add_tabstop (tabval);
189 /* Check that the list of tabstops TABS, with ENTRIES entries,
190 contains only nonzero, ascending values. */
193 validate_tabstops (int *tabs, int entries)
198 for (i = 0; i < entries; i++)
201 error (EXIT_FAILURE, 0, _("tab size cannot be 0"));
202 if (tabs[i] <= prev_tab)
203 error (EXIT_FAILURE, 0, _("tab sizes must be ascending"));
208 /* Close the old stream pointer FP if it is non-NULL,
209 and return a new one opened to read the next input file.
210 Open a filename of `-' as the standard input.
211 Return NULL if there are no more input files. */
216 static char *prev_file;
223 error (0, errno, "%s", prev_file);
227 clearerr (fp); /* Also clear EOF. */
228 else if (fclose (fp) == EOF)
230 error (0, errno, "%s", prev_file);
235 while ((file = *file_list++) != NULL)
237 if (file[0] == '-' && file[1] == '\0')
243 fp = fopen (file, "r");
249 error (0, errno, "%s", file);
255 /* Change tabs to spaces, writing to stdout.
256 Read each file in `file_list', in order. */
261 FILE *fp; /* Input stream. */
262 int c; /* Each input character. */
263 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
264 int column = 0; /* Column on screen of the next char. */
265 int next_tab_column; /* Column the next tab stop is on. */
266 int convert = 1; /* If nonzero, perform translations. */
268 fp = next_file ((FILE *) NULL);
272 /* Binary I/O will preserve the original EOL style (DOS/Unix) of files. */
273 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
282 break; /* No more files. */
285 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
297 else if (c == '\t' && convert)
301 /* Do not let tab_index == first_free_tab;
302 stop when it is 1 less. */
303 while (tab_index < first_free_tab - 1
304 && column >= tab_list[tab_index])
306 next_tab_column = tab_list[tab_index];
307 if (tab_index < first_free_tab - 1)
309 if (column >= next_tab_column)
310 next_tab_column = column + 1; /* Ran out of tab stops. */
314 next_tab_column = column + tab_size - column % tab_size;
316 while (column < next_tab_column)
334 if (convert_entire_line == 0)
344 main (int argc, char **argv)
346 int tabval = -1; /* Value of tabstop being read, or -1. */
347 int c; /* Option character. */
349 bool obsolete_tablist = false;
353 convert_entire_line = 1;
356 program_name = argv[0];
357 setlocale (LC_ALL, "");
358 bindtextdomain (PACKAGE, LOCALEDIR);
359 textdomain (PACKAGE);
361 atexit (close_stdout);
363 while ((c = getopt_long (argc, argv, shortopts, longopts, NULL)) != -1)
373 convert_entire_line = 0;
376 parse_tabstops (optarg);
378 case_GETOPT_HELP_CHAR;
379 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
381 #if POSIX2_VERSION < 200112
383 add_tabstop (tabval);
385 obsolete_tablist = true;
399 tabval = tabval * 10 + c - '0';
400 obsolete_tablist = true;
406 if (OBSOLETE_OPTION_WARNINGS
407 && obsolete_tablist && ! getenv ("POSIXLY_CORRECT"))
409 _("warning: `expand -TABLIST' is obsolete; use `expand -t TABLIST'"));
411 add_tabstop (tabval);
413 validate_tabstops (tab_list, first_free_tab);
415 if (first_free_tab == 0)
417 else if (first_free_tab == 1)
418 tab_size = tab_list[0];
423 file_list = stdin_argv;
425 file_list = &argv[optind];
429 if (have_read_stdin && fclose (stdin) == EOF)
430 error (EXIT_FAILURE, errno, "-");
432 exit (exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);