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\
117 Mandatory arguments to long options are mandatory for short options too.\n\
118 -i, --initial do not convert TABs after non whitespace\n\
119 -t, --tabs=NUMBER have tabs NUMBER characters apart, not 8\n\
120 -t, --tabs=LIST use comma separated list of explicit tab positions\n\
121 --help display this help and exit\n\
122 --version output version information and exit\n\
124 Instead of -t NUMBER or -t LIST, -NUMBER or -LIST may be used.\n\
126 puts (_("\nReport bugs to <bug-textutils@gnu.org>."));
128 exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
131 /* Add tab stop TABVAL to the end of `tab_list', except
132 if TABVAL is -1, do nothing. */
135 add_tabstop (int tabval)
139 if (first_free_tab % TABLIST_BLOCK == 0)
140 tab_list = (int *) xrealloc ((char *) tab_list,
142 + TABLIST_BLOCK * sizeof (tab_list[0])));
143 tab_list[first_free_tab++] = tabval;
146 /* Add the comma or blank separated list of tabstops STOPS
147 to the list of tabstops. */
150 parse_tabstops (char *stops)
154 for (; *stops; stops++)
156 if (*stops == ',' || ISBLANK (*stops))
158 add_tabstop (tabval);
161 else if (ISDIGIT (*stops))
165 tabval = tabval * 10 + *stops - '0';
168 error (EXIT_FAILURE, 0, _("tab size contains an invalid character"));
171 add_tabstop (tabval);
174 /* Check that the list of tabstops TABS, with ENTRIES entries,
175 contains only nonzero, ascending values. */
178 validate_tabstops (int *tabs, int entries)
183 for (i = 0; i < entries; i++)
186 error (EXIT_FAILURE, 0, _("tab size cannot be 0"));
187 if (tabs[i] <= prev_tab)
188 error (EXIT_FAILURE, 0, _("tab sizes must be ascending"));
193 /* Close the old stream pointer FP if it is non-NULL,
194 and return a new one opened to read the next input file.
195 Open a filename of `-' as the standard input.
196 Return NULL if there are no more input files. */
201 static char *prev_file;
208 error (0, errno, "%s", prev_file);
212 clearerr (fp); /* Also clear EOF. */
213 else if (fclose (fp) == EOF)
215 error (0, errno, "%s", prev_file);
220 while ((file = *file_list++) != NULL)
222 if (file[0] == '-' && file[1] == '\0')
228 fp = fopen (file, "r");
234 error (0, errno, "%s", file);
240 /* Change tabs to spaces, writing to stdout.
241 Read each file in `file_list', in order. */
246 FILE *fp; /* Input stream. */
247 int c; /* Each input character. */
248 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
249 int column = 0; /* Column on screen of the next char. */
250 int next_tab_column; /* Column the next tab stop is on. */
251 int convert = 1; /* If nonzero, perform translations. */
253 fp = next_file ((FILE *) NULL);
257 /* Binary I/O will preserve the original EOL style (DOS/Unix) of files. */
258 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
267 break; /* No more files. */
270 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
282 else if (c == '\t' && convert)
286 /* Do not let tab_index == first_free_tab;
287 stop when it is 1 less. */
288 while (tab_index < first_free_tab - 1
289 && column >= tab_list[tab_index])
291 next_tab_column = tab_list[tab_index];
292 if (tab_index < first_free_tab - 1)
294 if (column >= next_tab_column)
295 next_tab_column = column + 1; /* Ran out of tab stops. */
299 next_tab_column = column + tab_size - column % tab_size;
301 while (column < next_tab_column)
319 if (convert_entire_line == 0)
329 main (int argc, char **argv)
331 int tabval = -1; /* Value of tabstop being read, or -1. */
332 int c; /* Option character. */
336 convert_entire_line = 1;
339 program_name = argv[0];
340 setlocale (LC_ALL, "");
341 bindtextdomain (PACKAGE, LOCALEDIR);
342 textdomain (PACKAGE);
344 atexit (close_stdout);
346 while ((c = getopt_long (argc, argv, "it:,0123456789", longopts, NULL)) != -1)
356 convert_entire_line = 0;
359 parse_tabstops (optarg);
362 add_tabstop (tabval);
365 case_GETOPT_HELP_CHAR;
366 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
370 tabval = tabval * 10 + c - '0';
375 add_tabstop (tabval);
377 validate_tabstops (tab_list, first_free_tab);
379 if (first_free_tab == 0)
381 else if (first_free_tab == 1)
382 tab_size = tab_list[0];
387 file_list = stdin_argv;
389 file_list = &argv[optind];
393 if (have_read_stdin && fclose (stdin) == EOF)
394 error (EXIT_FAILURE, errno, "-");
396 exit (exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);