1 /* expand - convert tabs to spaces
2 Copyright (C) 1989, 1991 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., 675 Mass Ave, Cambridge, MA 02139, 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> */
36 /* Get isblank from GNU libc. */
41 #include <sys/types.h>
45 /* The number of bytes added at a time to the amount of memory
46 allocated for the output line. */
47 #define OUTPUT_BLOCK 256
49 /* The number of bytes added at a time to the amount of memory
50 allocated for the list of tabstops. */
51 #define TABLIST_BLOCK 256
57 static FILE *next_file ();
58 static void add_tabstop ();
59 static void expand ();
60 static void parse_tabstops ();
62 static void validate_tabstops ();
64 /* The name this program was run with. */
67 /* If nonzero, convert blanks even after nonblank characters have been
69 static int convert_entire_line;
71 /* If nonzero, the size of all tab stops. If zero, use `tab_list' instead. */
74 /* Array of the explicit column numbers of the tab stops;
75 after `tab_list' is exhausted, each additional tab is replaced
76 by a space. The first column is column 0. */
79 /* The index of the first invalid element of `tab_list',
80 where the next element can be added. */
81 static int first_free_tab;
83 /* Null-terminated array of input filenames. */
84 static char **file_list;
86 /* Default for `file_list' if no files are given on the command line. */
87 static char *stdin_argv[] =
92 /* Nonzero if we have ever read standard input. */
93 static int have_read_stdin;
95 /* Status to return to the system. */
96 static int exit_status;
98 /* If non-zero, display usage information and exit. */
101 /* If non-zero, print the version on standard error. */
102 static int flag_version;
104 static struct option const longopts[] =
106 {"tabs", required_argument, NULL, 't'},
107 {"initial", no_argument, NULL, 'i'},
108 {"help", no_argument, &flag_help, 1},
109 {"version", no_argument, &flag_version, 1},
118 int tabval = -1; /* Value of tabstop being read, or -1. */
119 int c; /* Option character. */
123 convert_entire_line = 1;
126 program_name = argv[0];
128 while ((c = getopt_long (argc, argv, "it:,0123456789", longopts, (int *) 0))
139 convert_entire_line = 0;
142 parse_tabstops (optarg);
145 add_tabstop (tabval);
151 tabval = tabval * 10 + c - '0';
157 fprintf (stderr, "%s\n", version_string);
162 add_tabstop (tabval);
164 validate_tabstops (tab_list, first_free_tab);
166 if (first_free_tab == 0)
168 else if (first_free_tab == 1)
169 tab_size = tab_list[0];
174 file_list = stdin_argv;
176 file_list = &argv[optind];
180 if (have_read_stdin && fclose (stdin) == EOF)
181 error (1, errno, "-");
182 if (ferror (stdout) || fclose (stdout) == EOF)
183 error (1, errno, "write error");
188 /* Add the comma or blank separated list of tabstops STOPS
189 to the list of tabstops. */
192 parse_tabstops (stops)
197 for (; *stops; stops++)
199 if (*stops == ',' || ISBLANK (*stops))
201 add_tabstop (tabval);
204 else if (ISDIGIT (*stops))
208 tabval = tabval * 10 + *stops - '0';
211 error (1, 0, "tab size contains an invalid character");
214 add_tabstop (tabval);
217 /* Add tab stop TABVAL to the end of `tab_list', except
218 if TABVAL is -1, do nothing. */
226 if (first_free_tab % TABLIST_BLOCK == 0)
227 tab_list = (int *) xrealloc (tab_list, first_free_tab + TABLIST_BLOCK);
228 tab_list[first_free_tab++] = tabval;
231 /* Check that the list of tabstops TABS, with ENTRIES entries,
232 contains only nonzero, ascending values. */
235 validate_tabstops (tabs, entries)
242 for (i = 0; i < entries; i++)
245 error (1, 0, "tab size cannot be 0");
246 if (tabs[i] <= prev_tab)
247 error (1, 0, "tab sizes must be ascending");
252 /* Change tabs to spaces, writing to stdout.
253 Read each file in `file_list', in order. */
258 FILE *fp; /* Input stream. */
259 int c; /* Each input character. */
260 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
261 int column = 0; /* Column on screen of the next char. */
262 int next_tab_column; /* Column the next tab stop is on. */
263 int convert = 1; /* If nonzero, perform translations. */
265 fp = next_file ((FILE *) NULL);
273 break; /* No more files. */
285 else if (c == '\t' && convert)
289 /* Do not let tab_index == first_free_tab;
290 stop when it is 1 less. */
291 while (tab_index < first_free_tab - 1
292 && column >= tab_list[tab_index])
294 next_tab_column = tab_list[tab_index];
295 if (tab_index < first_free_tab - 1)
297 if (column >= next_tab_column)
298 next_tab_column = column + 1; /* Ran out of tab stops. */
302 next_tab_column = column + tab_size - column % tab_size;
304 while (column < next_tab_column)
322 if (convert_entire_line == 0)
331 /* Close the old stream pointer FP if it is non-NULL,
332 and return a new one opened to read the next input file.
333 Open a filename of `-' as the standard input.
334 Return NULL if there are no more input files. */
340 static char *prev_file;
347 error (0, errno, "%s", prev_file);
351 clearerr (fp); /* Also clear EOF. */
352 else if (fclose (fp) == EOF)
354 error (0, errno, "%s", prev_file);
359 while ((file = *file_list++) != NULL)
361 if (file[0] == '-' && file[1] == '\0')
367 fp = fopen (file, "r");
373 error (0, errno, "%s", file);
383 Usage: %s [-tab1[,tab2[,...]]] [-t tab1[,tab2[,...]]] [-i]\n\
384 [--tabs=tab1[,tab2[,...]]] [--initial] [--help] [--version] [file...]\n",