1 /* expand - convert tabs to spaces
2 Copyright (C) 1989, 1991, 1995 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
16 Foundation, 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> */
38 /* Get isblank from GNU libc. */
43 #include <sys/types.h>
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
59 /* The name this program was run with. */
62 /* If nonzero, convert blanks even after nonblank characters have been
64 static int convert_entire_line;
66 /* If nonzero, the size of all tab stops. If zero, use `tab_list' instead. */
69 /* Array of the explicit column numbers of the tab stops;
70 after `tab_list' is exhausted, each additional tab is replaced
71 by a space. The first column is column 0. */
74 /* The index of the first invalid element of `tab_list',
75 where the next element can be added. */
76 static int first_free_tab;
78 /* Null-terminated array of input filenames. */
79 static char **file_list;
81 /* Default for `file_list' if no files are given on the command line. */
82 static char *stdin_argv[] =
87 /* Nonzero if we have ever read standard input. */
88 static int have_read_stdin;
90 /* Status to return to the system. */
91 static int exit_status;
93 /* If non-zero, display usage information and exit. */
96 /* If non-zero, print the version on standard output then exit. */
97 static int show_version;
99 static struct option const longopts[] =
101 {"tabs", required_argument, NULL, 't'},
102 {"initial", no_argument, NULL, 'i'},
103 {"help", no_argument, &show_help, 1},
104 {"version", no_argument, &show_version, 1},
112 fprintf (stderr, _("Try `%s --help' for more information.\n"),
117 Usage: %s [OPTION]... [FILE]...\n\
121 Convert tabs in each FILE to spaces, writing to standard output.\n\
122 With no FILE, or when FILE is -, read standard input.\n\
124 -i, --initial do not convert TABs after non whitespace\n\
125 -t, --tabs=NUMBER have tabs NUMBER characters apart, not 8\n\
126 -t, --tabs=LIST use comma separated list of explicit tab positions\n\
127 --help display this help and exit\n\
128 --version output version information and exit\n\
130 Instead of -t NUMBER or -t LIST, -NUMBER or -LIST may be used.\n\
136 /* Add tab stop TABVAL to the end of `tab_list', except
137 if TABVAL is -1, do nothing. */
140 add_tabstop (int tabval)
144 if (first_free_tab % TABLIST_BLOCK == 0)
145 tab_list = (int *) xrealloc (tab_list, first_free_tab
146 + TABLIST_BLOCK * sizeof (tab_list[0]));
147 tab_list[first_free_tab++] = tabval;
150 /* Add the comma or blank separated list of tabstops STOPS
151 to the list of tabstops. */
154 parse_tabstops (char *stops)
158 for (; *stops; stops++)
160 if (*stops == ',' || ISBLANK (*stops))
162 add_tabstop (tabval);
165 else if (ISDIGIT (*stops))
169 tabval = tabval * 10 + *stops - '0';
172 error (1, 0, _("tab size contains an invalid character"));
175 add_tabstop (tabval);
178 /* Check that the list of tabstops TABS, with ENTRIES entries,
179 contains only nonzero, ascending values. */
182 validate_tabstops (int *tabs, int entries)
187 for (i = 0; i < entries; i++)
190 error (1, 0, _("tab size cannot be 0"));
191 if (tabs[i] <= prev_tab)
192 error (1, 0, _("tab sizes must be ascending"));
197 /* Close the old stream pointer FP if it is non-NULL,
198 and return a new one opened to read the next input file.
199 Open a filename of `-' as the standard input.
200 Return NULL if there are no more input files. */
205 static char *prev_file;
212 error (0, errno, "%s", prev_file);
216 clearerr (fp); /* Also clear EOF. */
217 else if (fclose (fp) == EOF)
219 error (0, errno, "%s", prev_file);
224 while ((file = *file_list++) != NULL)
226 if (file[0] == '-' && file[1] == '\0')
232 fp = fopen (file, "r");
238 error (0, errno, "%s", file);
244 /* Change tabs to spaces, writing to stdout.
245 Read each file in `file_list', in order. */
250 FILE *fp; /* Input stream. */
251 int c; /* Each input character. */
252 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
253 int column = 0; /* Column on screen of the next char. */
254 int next_tab_column; /* Column the next tab stop is on. */
255 int convert = 1; /* If nonzero, perform translations. */
257 fp = next_file ((FILE *) NULL);
267 break; /* No more files. */
279 else if (c == '\t' && convert)
283 /* Do not let tab_index == first_free_tab;
284 stop when it is 1 less. */
285 while (tab_index < first_free_tab - 1
286 && column >= tab_list[tab_index])
288 next_tab_column = tab_list[tab_index];
289 if (tab_index < first_free_tab - 1)
291 if (column >= next_tab_column)
292 next_tab_column = column + 1; /* Ran out of tab stops. */
296 next_tab_column = column + tab_size - column % tab_size;
298 while (column < next_tab_column)
316 if (convert_entire_line == 0)
326 main (int argc, char **argv)
328 int tabval = -1; /* Value of tabstop being read, or -1. */
329 int c; /* Option character. */
333 convert_entire_line = 1;
336 program_name = argv[0];
338 while ((c = getopt_long (argc, argv, "it:,0123456789", longopts, (int *) 0))
349 convert_entire_line = 0;
352 parse_tabstops (optarg);
355 add_tabstop (tabval);
361 tabval = tabval * 10 + c - '0';
368 printf ("expand - %s\n", version_string);
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 (1, errno, "-");
395 if (ferror (stdout) || fclose (stdout) == EOF)
396 error (1, errno, _("write error"));