1 /* unexpand - convert spaces to tabs
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 only maximal strings of initial blanks and tabs
20 Preserves backspace characters in the output; they decrement the
21 column count for tab calculations.
22 The default action is equivalent to -8.
25 --tabs=tab1[,tab2[,...]]
27 -tab1[,tab2[,...]] If only one tab stop is given, set the tabs tab1
28 spaces apart instead of the default 8. Otherwise,
29 set the tabs at columns tab1, tab2, etc. (numbered from
30 0); replace any tabs beyond the tabstops given with
33 -a Use tabs wherever they would replace 2 or more spaces,
34 not just at the beginnings of lines.
36 David MacKenzie <djm@gnu.ai.mit.edu> */
38 /* Get isblank from GNU libc. */
43 #include <sys/types.h>
47 /* The number of bytes added at a time to the amount of memory
48 allocated for the output line. */
49 #define OUTPUT_BLOCK 256
51 /* The number of bytes added at a time to the amount of memory
52 allocated for the list of tabstops. */
53 #define TABLIST_BLOCK 256
59 static FILE *next_file ();
60 static void add_tabstop ();
61 static void parse_tabstops ();
62 static void unexpand ();
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, the rest of the line is printed
78 unchanged. 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 {"all", no_argument, NULL, 'a'},
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 = 0;
128 program_name = argv[0];
130 while ((c = getopt_long (argc, argv, "at:,0123456789", longopts, (int *) 0))
141 convert_entire_line = 1;
144 convert_entire_line = 1;
145 parse_tabstops (optarg);
148 add_tabstop (tabval);
154 tabval = tabval * 10 + c - '0';
161 printf ("%s\n", version_string);
168 add_tabstop (tabval);
170 validate_tabstops (tab_list, first_free_tab);
172 if (first_free_tab == 0)
174 else if (first_free_tab == 1)
175 tab_size = tab_list[0];
180 file_list = stdin_argv;
182 file_list = &argv[optind];
186 if (have_read_stdin && fclose (stdin) == EOF)
187 error (1, errno, "-");
188 if (fclose (stdout) == EOF)
189 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 spaces to tabs, writing to stdout.
258 Read each file in `file_list', in order. */
263 FILE *fp; /* Input stream. */
264 int c; /* Each input character. */
265 /* Index in `tab_list' of next tabstop: */
266 int tab_index = 0; /* For calculating width of pending tabs. */
267 int print_tab_index = 0; /* For printing as many tabs as possible. */
268 int column = 0; /* Column on screen of next char. */
269 int next_tab_column; /* Column the next tab stop is on. */
270 int convert = 1; /* If nonzero, perform translations. */
271 int pending = 0; /* Pending columns of blanks. */
273 fp = next_file ((FILE *) NULL);
281 break; /* No more files. */
286 if (c == ' ' && convert)
291 else if (c == '\t' && convert)
295 /* Do not let tab_index == first_free_tab;
296 stop when it is 1 less. */
297 while (tab_index < first_free_tab - 1
298 && column >= tab_list[tab_index])
300 next_tab_column = tab_list[tab_index];
301 if (tab_index < first_free_tab - 1)
303 if (column >= next_tab_column)
305 convert = 0; /* Ran out of tab stops. */
311 next_tab_column = column + tab_size - column % tab_size;
313 pending += next_tab_column - column;
314 column = next_tab_column;
319 /* Flush pending spaces. Print as many tabs as possible,
320 then print the rest as spaces. */
331 /* Do not let tab_index == first_free_tab;
332 stop when it is 1 less. */
333 while (tab_index < first_free_tab - 1
334 && column >= tab_list[tab_index])
336 next_tab_column = tab_list[print_tab_index];
337 if (print_tab_index < first_free_tab - 1)
342 next_tab_column = column + tab_size - column % tab_size;
344 if (next_tab_column - column <= pending)
347 pending -= next_tab_column - column;
348 column = next_tab_column;
372 if (convert_entire_line == 0)
381 tab_index = print_tab_index = 0;
382 column = pending = 0;
389 /* Close the old stream pointer FP if it is non-NULL,
390 and return a new one opened to read the next input file.
391 Open a filename of `-' as the standard input.
392 Return NULL if there are no more input files. */
398 static char *prev_file;
405 error (0, errno, "%s", prev_file);
409 clearerr (fp); /* Also clear EOF. */
410 else if (fclose (fp) == EOF)
412 error (0, errno, "%s", prev_file);
417 while ((file = *file_list++) != NULL)
419 if (file[0] == '-' && file[1] == '\0')
425 fp = fopen (file, "r");
431 error (0, errno, "%s", file);
441 Usage: %s [-tab1[,tab2[,...]]] [-t tab1[,tab2[,...]]] [-a]\n\
442 [--tabs=tab1[,tab2[,...]]] [--all] [--help] [--version] [file...]\n",