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\
129 --help display this help and exit\n\
130 --version output version information and exit\n\
134 Instead of -t NUMBER or -t LIST, -NUMBER or -LIST may be used.\n\
136 puts (_("\nReport bugs to <bug-textutils@gnu.org>."));
138 exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
141 /* Add tab stop TABVAL to the end of `tab_list', except
142 if TABVAL is -1, do nothing. */
145 add_tabstop (int tabval)
149 if (first_free_tab % TABLIST_BLOCK == 0)
150 tab_list = (int *) xrealloc ((char *) tab_list,
152 + TABLIST_BLOCK * sizeof (tab_list[0])));
153 tab_list[first_free_tab++] = tabval;
156 /* Add the comma or blank separated list of tabstops STOPS
157 to the list of tabstops. */
160 parse_tabstops (char *stops)
164 for (; *stops; stops++)
166 if (*stops == ',' || ISBLANK (*stops))
168 add_tabstop (tabval);
171 else if (ISDIGIT (*stops))
175 tabval = tabval * 10 + *stops - '0';
178 error (EXIT_FAILURE, 0, _("tab size contains an invalid character"));
181 add_tabstop (tabval);
184 /* Check that the list of tabstops TABS, with ENTRIES entries,
185 contains only nonzero, ascending values. */
188 validate_tabstops (int *tabs, int entries)
193 for (i = 0; i < entries; i++)
196 error (EXIT_FAILURE, 0, _("tab size cannot be 0"));
197 if (tabs[i] <= prev_tab)
198 error (EXIT_FAILURE, 0, _("tab sizes must be ascending"));
203 /* Close the old stream pointer FP if it is non-NULL,
204 and return a new one opened to read the next input file.
205 Open a filename of `-' as the standard input.
206 Return NULL if there are no more input files. */
211 static char *prev_file;
218 error (0, errno, "%s", prev_file);
222 clearerr (fp); /* Also clear EOF. */
223 else if (fclose (fp) == EOF)
225 error (0, errno, "%s", prev_file);
230 while ((file = *file_list++) != NULL)
232 if (file[0] == '-' && file[1] == '\0')
238 fp = fopen (file, "r");
244 error (0, errno, "%s", file);
250 /* Change tabs to spaces, writing to stdout.
251 Read each file in `file_list', in order. */
256 FILE *fp; /* Input stream. */
257 int c; /* Each input character. */
258 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
259 int column = 0; /* Column on screen of the next char. */
260 int next_tab_column; /* Column the next tab stop is on. */
261 int convert = 1; /* If nonzero, perform translations. */
263 fp = next_file ((FILE *) NULL);
267 /* Binary I/O will preserve the original EOL style (DOS/Unix) of files. */
268 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
277 break; /* No more files. */
280 SET_BINARY2 (fileno (fp), STDOUT_FILENO);
292 else if (c == '\t' && convert)
296 /* Do not let tab_index == first_free_tab;
297 stop when it is 1 less. */
298 while (tab_index < first_free_tab - 1
299 && column >= tab_list[tab_index])
301 next_tab_column = tab_list[tab_index];
302 if (tab_index < first_free_tab - 1)
304 if (column >= next_tab_column)
305 next_tab_column = column + 1; /* Ran out of tab stops. */
309 next_tab_column = column + tab_size - column % tab_size;
311 while (column < next_tab_column)
329 if (convert_entire_line == 0)
339 main (int argc, char **argv)
341 int tabval = -1; /* Value of tabstop being read, or -1. */
342 int c; /* Option character. */
346 convert_entire_line = 1;
349 program_name = argv[0];
350 setlocale (LC_ALL, "");
351 bindtextdomain (PACKAGE, LOCALEDIR);
352 textdomain (PACKAGE);
354 atexit (close_stdout);
356 while ((c = getopt_long (argc, argv, "it:,0123456789", longopts, NULL)) != -1)
366 convert_entire_line = 0;
369 parse_tabstops (optarg);
372 add_tabstop (tabval);
375 case_GETOPT_HELP_CHAR;
376 case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
380 tabval = tabval * 10 + c - '0';
385 add_tabstop (tabval);
387 validate_tabstops (tab_list, first_free_tab);
389 if (first_free_tab == 0)
391 else if (first_free_tab == 1)
392 tab_size = tab_list[0];
397 file_list = stdin_argv;
399 file_list = &argv[optind];
403 if (have_read_stdin && fclose (stdin) == EOF)
404 error (EXIT_FAILURE, errno, "-");
406 exit (exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);