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 output then exit. */
102 static int show_version;
104 static struct option const longopts[] =
106 {"tabs", required_argument, NULL, 't'},
107 {"initial", no_argument, NULL, 'i'},
108 {"help", no_argument, &show_help, 1},
109 {"version", no_argument, &show_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';
158 printf ("%s\n", version_string);
165 add_tabstop (tabval);
167 validate_tabstops (tab_list, first_free_tab);
169 if (first_free_tab == 0)
171 else if (first_free_tab == 1)
172 tab_size = tab_list[0];
177 file_list = stdin_argv;
179 file_list = &argv[optind];
183 if (have_read_stdin && fclose (stdin) == EOF)
184 error (1, errno, "-");
185 if (ferror (stdout) || fclose (stdout) == EOF)
186 error (1, errno, "write error");
191 /* Add the comma or blank separated list of tabstops STOPS
192 to the list of tabstops. */
195 parse_tabstops (stops)
200 for (; *stops; stops++)
202 if (*stops == ',' || ISBLANK (*stops))
204 add_tabstop (tabval);
207 else if (ISDIGIT (*stops))
211 tabval = tabval * 10 + *stops - '0';
214 error (1, 0, "tab size contains an invalid character");
217 add_tabstop (tabval);
220 /* Add tab stop TABVAL to the end of `tab_list', except
221 if TABVAL is -1, do nothing. */
229 if (first_free_tab % TABLIST_BLOCK == 0)
230 tab_list = (int *) xrealloc (tab_list, first_free_tab + TABLIST_BLOCK);
231 tab_list[first_free_tab++] = tabval;
234 /* Check that the list of tabstops TABS, with ENTRIES entries,
235 contains only nonzero, ascending values. */
238 validate_tabstops (tabs, entries)
245 for (i = 0; i < entries; i++)
248 error (1, 0, "tab size cannot be 0");
249 if (tabs[i] <= prev_tab)
250 error (1, 0, "tab sizes must be ascending");
255 /* Change tabs to spaces, writing to stdout.
256 Read each file in `file_list', in order. */
261 FILE *fp; /* Input stream. */
262 int c; /* Each input character. */
263 int tab_index = 0; /* Index in `tab_list' of next tabstop. */
264 int column = 0; /* Column on screen of the next char. */
265 int next_tab_column; /* Column the next tab stop is on. */
266 int convert = 1; /* If nonzero, perform translations. */
268 fp = next_file ((FILE *) NULL);
276 break; /* No more files. */
288 else if (c == '\t' && convert)
292 /* Do not let tab_index == first_free_tab;
293 stop when it is 1 less. */
294 while (tab_index < first_free_tab - 1
295 && column >= tab_list[tab_index])
297 next_tab_column = tab_list[tab_index];
298 if (tab_index < first_free_tab - 1)
300 if (column >= next_tab_column)
301 next_tab_column = column + 1; /* Ran out of tab stops. */
305 next_tab_column = column + tab_size - column % tab_size;
307 while (column < next_tab_column)
325 if (convert_entire_line == 0)
334 /* Close the old stream pointer FP if it is non-NULL,
335 and return a new one opened to read the next input file.
336 Open a filename of `-' as the standard input.
337 Return NULL if there are no more input files. */
343 static char *prev_file;
350 error (0, errno, "%s", prev_file);
354 clearerr (fp); /* Also clear EOF. */
355 else if (fclose (fp) == EOF)
357 error (0, errno, "%s", prev_file);
362 while ((file = *file_list++) != NULL)
364 if (file[0] == '-' && file[1] == '\0')
370 fp = fopen (file, "r");
376 error (0, errno, "%s", file);
386 Usage: %s [-tab1[,tab2[,...]]] [-t tab1[,tab2[,...]]] [-i]\n\
387 [--tabs=tab1[,tab2[,...]]] [--initial] [--help] [--version] [file...]\n",