1 /* expand - convert tabs to spaces
2 Copyright (C) 89, 91, 1995-1999 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>
43 #include "long-options.h"
45 /* The official name of this program (e.g., no `g' prefix). */
46 #define PROGRAM_NAME "expand"
48 /* The number of bytes added at a time to the amount of memory
49 allocated for the output line. */
50 #define OUTPUT_BLOCK 256
52 /* The number of bytes added at a time to the amount of memory
53 allocated for the list of tabstops. */
54 #define TABLIST_BLOCK 256
56 /* The name this program was run with. */
59 /* If nonzero, convert blanks even after nonblank characters have been
61 static int convert_entire_line;
63 /* If nonzero, the size of all tab stops. If zero, use `tab_list' instead. */
66 /* Array of the explicit column numbers of the tab stops;
67 after `tab_list' is exhausted, each additional tab is replaced
68 by a space. The first column is column 0. */
71 /* The index of the first invalid element of `tab_list',
72 where the next element can be added. */
73 static int first_free_tab;
75 /* Null-terminated array of input filenames. */
76 static char **file_list;
78 /* Default for `file_list' if no files are given on the command line. */
79 static char *stdin_argv[] =
84 /* Nonzero if we have ever read standard input. */
85 static int have_read_stdin;
87 /* Status to return to the system. */
88 static int exit_status;
90 static struct option const longopts[] =
92 {"tabs", required_argument, NULL, 't'},
93 {"initial", no_argument, NULL, 'i'},
101 fprintf (stderr, _("Try `%s --help' for more information.\n"),
106 Usage: %s [OPTION]... [FILE]...\n\
110 Convert tabs in each FILE to spaces, writing to standard output.\n\
111 With no FILE, or when FILE is -, read standard input.\n\
113 -i, --initial do not convert TABs after non whitespace\n\
114 -t, --tabs=NUMBER have tabs NUMBER characters apart, not 8\n\
115 -t, --tabs=LIST use comma separated list of explicit tab positions\n\
116 --help display this help and exit\n\
117 --version output version information and exit\n\
119 Instead of -t NUMBER or -t LIST, -NUMBER or -LIST may be used.\n\
121 puts (_("\nReport bugs to <bug-textutils@gnu.org>."));
123 exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
126 /* Add tab stop TABVAL to the end of `tab_list', except
127 if TABVAL is -1, do nothing. */
130 add_tabstop (int tabval)
134 if (first_free_tab % TABLIST_BLOCK == 0)
135 tab_list = (int *) xrealloc ((char *) tab_list,
137 + TABLIST_BLOCK * sizeof (tab_list[0])));
138 tab_list[first_free_tab++] = tabval;
141 /* Add the comma or blank separated list of tabstops STOPS
142 to the list of tabstops. */
145 parse_tabstops (char *stops)
149 for (; *stops; stops++)
151 if (*stops == ',' || ISBLANK (*stops))
153 add_tabstop (tabval);
156 else if (ISDIGIT (*stops))
160 tabval = tabval * 10 + *stops - '0';
163 error (EXIT_FAILURE, 0, _("tab size contains an invalid character"));
166 add_tabstop (tabval);
169 /* Check that the list of tabstops TABS, with ENTRIES entries,
170 contains only nonzero, ascending values. */
173 validate_tabstops (int *tabs, int entries)
178 for (i = 0; i < entries; i++)
181 error (EXIT_FAILURE, 0, _("tab size cannot be 0"));
182 if (tabs[i] <= prev_tab)
183 error (EXIT_FAILURE, 0, _("tab sizes must be ascending"));
188 /* Close the old stream pointer FP if it is non-NULL,
189 and return a new one opened to read the next input file.
190 Open a filename of `-' as the standard input.
191 Return NULL if there are no more input files. */
196 static char *prev_file;
203 error (0, errno, "%s", prev_file);
207 clearerr (fp); /* Also clear EOF. */
208 else if (fclose (fp) == EOF)
210 error (0, errno, "%s", prev_file);
215 while ((file = *file_list++) != NULL)
217 if (file[0] == '-' && file[1] == '\0')
223 fp = fopen (file, "r");
229 error (0, errno, "%s", file);
235 /* Change tabs to spaces, writing to stdout.
236 Read each file in `file_list', in order. */
241 FILE *fp; /* Input stream. */
242 int c; /* Each input character. */
243 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
244 int column = 0; /* Column on screen of the next char. */
245 int next_tab_column; /* Column the next tab stop is on. */
246 int convert = 1; /* If nonzero, perform translations. */
248 fp = next_file ((FILE *) NULL);
252 /* Binary I/O will preserve the original EOL style (DOS/Unix) of files. */
253 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
262 break; /* No more files. */
265 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
277 else if (c == '\t' && convert)
281 /* Do not let tab_index == first_free_tab;
282 stop when it is 1 less. */
283 while (tab_index < first_free_tab - 1
284 && column >= tab_list[tab_index])
286 next_tab_column = tab_list[tab_index];
287 if (tab_index < first_free_tab - 1)
289 if (column >= next_tab_column)
290 next_tab_column = column + 1; /* Ran out of tab stops. */
294 next_tab_column = column + tab_size - column % tab_size;
296 while (column < next_tab_column)
314 if (convert_entire_line == 0)
324 main (int argc, char **argv)
326 int tabval = -1; /* Value of tabstop being read, or -1. */
327 int c; /* Option character. */
331 convert_entire_line = 1;
334 program_name = argv[0];
335 setlocale (LC_ALL, "");
336 bindtextdomain (PACKAGE, LOCALEDIR);
337 textdomain (PACKAGE);
339 parse_long_options (argc, argv, "expand", GNU_PACKAGE, VERSION,
340 "David MacKenzie", usage);
342 while ((c = getopt_long (argc, argv, "it:,0123456789", longopts, NULL)) != -1)
352 convert_entire_line = 0;
355 parse_tabstops (optarg);
358 add_tabstop (tabval);
364 tabval = tabval * 10 + c - '0';
369 add_tabstop (tabval);
371 validate_tabstops (tab_list, first_free_tab);
373 if (first_free_tab == 0)
375 else if (first_free_tab == 1)
376 tab_size = tab_list[0];
381 file_list = stdin_argv;
383 file_list = &argv[optind];
387 if (have_read_stdin && fclose (stdin) == EOF)
388 error (EXIT_FAILURE, errno, "-");
389 if (ferror (stdout) || fclose (stdout) == EOF)
390 error (EXIT_FAILURE, errno, _("write error"));
392 exit (exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);