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., 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> */
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 static FILE *next_file ();
60 static void add_tabstop ();
61 static void expand ();
62 static void parse_tabstops ();
64 static void validate_tabstops ();
66 /* The name this program was run with. */
69 /* If nonzero, convert blanks even after nonblank characters have been
71 static int convert_entire_line;
73 /* If nonzero, the size of all tab stops. If zero, use `tab_list' instead. */
76 /* Array of the explicit column numbers of the tab stops;
77 after `tab_list' is exhausted, each additional tab is replaced
78 by a space. The first column is column 0. */
81 /* The index of the first invalid element of `tab_list',
82 where the next element can be added. */
83 static int first_free_tab;
85 /* Null-terminated array of input filenames. */
86 static char **file_list;
88 /* Default for `file_list' if no files are given on the command line. */
89 static char *stdin_argv[] =
94 /* Nonzero if we have ever read standard input. */
95 static int have_read_stdin;
97 /* Status to return to the system. */
98 static int exit_status;
100 /* If non-zero, display usage information and exit. */
101 static int show_help;
103 /* If non-zero, print the version on standard output then exit. */
104 static int show_version;
106 static struct option const longopts[] =
108 {"tabs", required_argument, NULL, 't'},
109 {"initial", no_argument, NULL, 'i'},
110 {"help", no_argument, &show_help, 1},
111 {"version", no_argument, &show_version, 1},
120 int tabval = -1; /* Value of tabstop being read, or -1. */
121 int c; /* Option character. */
125 convert_entire_line = 1;
128 program_name = argv[0];
130 while ((c = getopt_long (argc, argv, "it:,0123456789", longopts, (int *) 0))
141 convert_entire_line = 0;
144 parse_tabstops (optarg);
147 add_tabstop (tabval);
153 tabval = tabval * 10 + c - '0';
160 printf ("expand - %s\n", version_string);
167 add_tabstop (tabval);
169 validate_tabstops (tab_list, first_free_tab);
171 if (first_free_tab == 0)
173 else if (first_free_tab == 1)
174 tab_size = tab_list[0];
179 file_list = stdin_argv;
181 file_list = &argv[optind];
185 if (have_read_stdin && fclose (stdin) == EOF)
186 error (1, errno, "-");
187 if (ferror (stdout) || fclose (stdout) == EOF)
188 error (1, errno, "write error");
193 /* Add the comma or blank separated list of tabstops STOPS
194 to the list of tabstops. */
197 parse_tabstops (stops)
202 for (; *stops; stops++)
204 if (*stops == ',' || ISBLANK (*stops))
206 add_tabstop (tabval);
209 else if (ISDIGIT (*stops))
213 tabval = tabval * 10 + *stops - '0';
216 error (1, 0, "tab size contains an invalid character");
219 add_tabstop (tabval);
222 /* Add tab stop TABVAL to the end of `tab_list', except
223 if TABVAL is -1, do nothing. */
231 if (first_free_tab % TABLIST_BLOCK == 0)
232 tab_list = (int *) xrealloc (tab_list, first_free_tab + TABLIST_BLOCK);
233 tab_list[first_free_tab++] = tabval;
236 /* Check that the list of tabstops TABS, with ENTRIES entries,
237 contains only nonzero, ascending values. */
240 validate_tabstops (tabs, entries)
247 for (i = 0; i < entries; i++)
250 error (1, 0, "tab size cannot be 0");
251 if (tabs[i] <= prev_tab)
252 error (1, 0, "tab sizes must be ascending");
257 /* Change tabs to spaces, writing to stdout.
258 Read each file in `file_list', in order. */
263 FILE *fp; /* Input stream. */
264 int c; /* Each input character. */
265 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
266 int column = 0; /* Column on screen of the next char. */
267 int next_tab_column; /* Column the next tab stop is on. */
268 int convert = 1; /* If nonzero, perform translations. */
270 fp = next_file ((FILE *) NULL);
280 break; /* No more files. */
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)
338 /* Close the old stream pointer FP if it is non-NULL,
339 and return a new one opened to read the next input file.
340 Open a filename of `-' as the standard input.
341 Return NULL if there are no more input files. */
347 static char *prev_file;
354 error (0, errno, "%s", prev_file);
358 clearerr (fp); /* Also clear EOF. */
359 else if (fclose (fp) == EOF)
361 error (0, errno, "%s", prev_file);
366 while ((file = *file_list++) != NULL)
368 if (file[0] == '-' && file[1] == '\0')
374 fp = fopen (file, "r");
380 error (0, errno, "%s", file);
391 fprintf (stderr, "Try `%s --help' for more information.\n",
396 Usage: %s [OPTION]... [FILE]...\n\
401 -i, --initial do not convert TABs after non whitespace\n\
402 -t, --tabs=NUMBER have tabs NUMBER characters apart, not 8\n\
403 -t, --tabs=LIST use comma separated list of explicit tab positions\n\
404 --help display this help and exit\n\
405 --version output version information and exit\n\
407 Instead of -t NUMBER or -t LIST, -NUMBER or -LIST may be used. With\n\
408 no FILE, or when FILE is -, read standard input.\n\