1 /* alias.c -- Not a full alias, but just the kind that we use in the
2 shell. Csh style alias is somewhere else (`over there, in a box'). */
4 /* Copyright (C) 1987,1991 Free Software Foundation, Inc.
6 This file is part of GNU Bash, the Bourne Again SHell.
8 Bash is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 1, or (at your option)
13 Bash is distributed in the hope that it will be useful, but WITHOUT
14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
16 License for more details.
18 You should have received a copy of the GNU General Public License
19 along with Bash; see the file COPYING. If not, write to the Free
20 Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
26 #if defined (HAVE_UNISTD_H)
37 static int qsort_alias_compare ();
39 /* Non-zero means expand all words on the line. Otherwise, expand
40 after first expansion if the expansion ends in a space. */
41 int alias_expand_all = 0;
43 /* The list of aliases that we have. */
44 HASH_TABLE *aliases = (HASH_TABLE *)NULL;
50 aliases = make_hash_table (0);
53 /* Scan the list of aliases looking for one with NAME. Return NULL
54 if the alias doesn't exist, else a pointer to the alias_t. */
62 return ((alias_t *)NULL);
64 al = find_hash_item (name, aliases);
65 return (al ? (alias_t *)al->data : (alias_t *)NULL);
68 /* Return the value of the alias for NAME, or NULL if there is none. */
70 get_alias_value (name)
76 return ((char *)NULL);
78 alias = find_alias (name);
79 return (alias ? alias->value : (char *)NULL);
82 /* Make a new alias from NAME and VALUE. If NAME can be found,
83 then replace its value. */
85 add_alias (name, value)
94 initialize_aliases ();
95 temp = (alias_t *)NULL;
98 temp = find_alias (name);
103 temp->value = savestring (value);
104 n = value[strlen (value) - 1];
105 if (n == ' ' || n == '\t')
106 temp->flags |= AL_EXPANDNEXT;
110 temp = (alias_t *)xmalloc (sizeof (alias_t));
111 temp->name = savestring (name);
112 temp->value = savestring (value);
115 n = value[strlen (value) - 1];
116 if (n == ' ' || n == '\t')
117 temp->flags |= AL_EXPANDNEXT;
119 elt = add_hash_item (savestring (name), aliases);
120 elt->data = (char *)temp;
124 /* Delete a single alias structure. */
126 free_alias_data (data)
137 /* Remove the alias with name NAME from the alias table. Returns
138 the number of aliases left in the table, or -1 if the alias didn't
144 BUCKET_CONTENTS *elt;
149 elt = remove_hash_item (name, aliases);
152 free_alias_data (elt->data);
153 free (elt->key); /* alias name */
154 free (elt); /* XXX */
155 return (aliases->nentries);
160 /* Delete all aliases. */
162 delete_all_aliases ()
167 flush_hash_table (aliases, free_alias_data);
168 dispose_hash_table (aliases);
169 aliases = (HASH_TABLE *)NULL;
172 /* Return an array of aliases that satisfy the conditions tested by FUNCTION.
173 If FUNCTION is NULL, return all aliases. */
175 map_over_aliases (function)
179 register BUCKET_CONTENTS *tlist;
180 alias_t *alias, **list;
181 int list_index, list_size;
183 list = (alias_t **)NULL;
184 for (i = list_index = list_size = 0; i < aliases->nbuckets; i++)
186 tlist = get_hash_bucket (i, aliases);
190 alias = (alias_t *)tlist->data;
192 if (!function || (*function) (alias))
194 if (list_index + 1 >= list_size)
196 xrealloc ((char *)list, (list_size += 20) * sizeof (alias_t *));
198 list[list_index++] = alias;
199 list[list_index] = (alias_t *)NULL;
211 qsort (array, array_len ((char **)array), sizeof (alias_t *), qsort_alias_compare);
215 qsort_alias_compare (as1, as2)
216 alias_t **as1, **as2;
220 if ((result = (*as1)->name[0] - (*as2)->name[0]) == 0)
221 result = strcmp ((*as1)->name, (*as2)->name);
226 /* Return a sorted list of all defined aliases */
233 return ((alias_t **)NULL);
235 list = map_over_aliases ((Function *)NULL);
242 alias_expand_word (s)
248 return (r ? savestring (r->value) : (char *)NULL);
251 /* Readline support functions -- expand all aliases in a line. */
253 #if defined (READLINE)
255 /* Return non-zero if CHARACTER is a member of the class of characters
256 that are self-delimiting in the shell (this really means that these
257 characters delimit tokens). */
258 #define self_delimiting(character) (member ((character), " \t\n\r;|&()"))
260 /* Return non-zero if CHARACTER is a member of the class of characters
261 that delimit commands in the shell. */
262 #define command_separator(character) (member ((character), "\r\n;|&("))
264 /* If this is 1, we are checking the next token read for alias expansion
265 because it is the first word in a command. */
266 static int command_word;
268 /* This is for skipping quoted strings in alias expansions. */
269 #define quote_char(c) (((c) == '\'') || ((c) == '"'))
271 /* Consume a quoted string from STRING, starting at string[START] (so
272 string[START] is the opening quote character), and return the index
273 of the closing quote character matching the opening quote character.
274 This handles single matching pairs of unquoted quotes; it could afford
275 to be a little smarter... This skips words between balanced pairs of
276 quotes, words where the first character is quoted with a `\', and other
277 backslash-escaped characters. */
280 skipquotes (string, start)
285 int delimiter = string[start];
287 /* i starts at START + 1 because string[START] is the opening quote
289 for (i = start + 1 ; string[i] ; i++)
291 if (string[i] == '\\')
293 i++; /* skip backslash-quoted quote characters, too */
297 if (string[i] == delimiter)
303 /* Skip the white space and any quoted characters in STRING, starting at
304 START. Return the new index into STRING, after zero or more characters
305 have been skipped. */
307 skipws (string, start)
312 int pass_next, backslash_quoted_word, peekc;
314 /* skip quoted strings, in ' or ", and words in which a character is quoted
316 backslash_quoted_word = pass_next = 0;
318 /* Skip leading whitespace (or separator characters), and quoted words.
319 But save it in the output. */
321 for (i = start; string[i]; i++)
329 if (whitespace (string[i]))
331 backslash_quoted_word = 0; /* we are no longer in a backslash-quoted word */
335 if (string[i] == '\\')
338 if (isletter (peekc))
339 backslash_quoted_word++; /* this is a backslash-quoted word */
345 /* This only handles single pairs of non-escaped quotes. This
346 overloads backslash_quoted_word to also mean that a word like
347 ""f is being scanned, so that the quotes will inhibit any expansion
349 if (quote_char(string[i]))
351 i = skipquotes (string, i);
352 /* This could be a line that contains a single quote character,
353 in which case skipquotes () terminates with string[i] == '\0'
354 (the end of the string). Check for that here. */
355 if (string[i] == '\0')
358 peekc = string[i + 1];
359 if (isletter (peekc))
360 backslash_quoted_word++;
364 /* If we're in the middle of some kind of quoted word, let it
366 if (backslash_quoted_word)
369 /* If this character is a shell command separator, then set a hint for
370 alias_expand that the next token is the first word in a command. */
372 if (command_separator (string[i]))
382 /* Characters that may appear in a token. Basically, anything except white
383 space and a token separator. */
384 #define token_char(c) (!((whitespace (string[i]) || self_delimiting (string[i]))))
386 /* Read from START in STRING until the next separator character, and return
387 the index of that separator. Skip backslash-quoted characters. Call
388 skipquotes () for quoted strings in the middle or at the end of tokens,
389 so all characters show up (e.g. foo'' and foo""bar) */
391 rd_token (string, start)
397 /* From here to next separator character is a token. */
398 for (i = start; string[i] && token_char (string[i]); i++)
400 if (string[i] == '\\')
402 i++; /* skip backslash-escaped character */
406 /* If this character is a quote character, we want to call skipquotes
407 to get the whole quoted portion as part of this word. That word
408 will not generally match an alias, even if te unquoted word would
409 have. The presence of the quotes in the token serves then to
410 inhibit expansion. */
411 if (quote_char (string[i]))
413 i = skipquotes (string, i);
414 /* Now string[i] is the matching quote character, and the
415 quoted portion of the token has been scanned. */
422 /* Return a new line, with any aliases substituted. */
424 alias_expand (string)
427 int line_len = 1 + strlen (string);
428 char *line = (char *)xmalloc (line_len);
429 register int i, j, start;
430 char *token = xmalloc (line_len);
431 int tl, real_start, expand_next, expand_this_token;
436 command_word = 1; /* initialized to expand the first word on the line */
438 /* Each time through the loop we find the next word in line. If it
439 has an alias, substitute
440 the alias value. If the value ends in ` ', then try again
441 with the next word. Else, if there is no value, or if
442 the value does not end in space, we are done. */
450 /* Skip white space and quoted characters */
451 i = skipws (string, start);
453 if (start == i && string[i] == '\0')
459 /* copy the just-skipped characters into the output string,
460 expanding it if there is not enough room. */
462 tl = i - start; /* number of characters just skipped */
463 RESIZE_MALLOCED_BUFFER (line, j, (tl + 1), line_len, (tl + 50));
464 strncpy (line + j, string + start, tl);
469 command_word = command_word || (command_separator (string[i]));
470 expand_this_token = (command_word || expand_next);
473 /* Read the next token, and copy it into TOKEN. */
475 i = rd_token (string, start);
477 tl = i - start; /* token length */
479 /* If tl == 0, but we're not at the end of the string, then we have a
480 single-character token, probably a delimiter */
481 if (tl == 0 && string[i] != '\0')
484 i++; /* move past it */
487 strncpy (token, string + start, tl);
490 /* If there is a backslash-escaped character quoted in TOKEN,
491 then we don't do alias expansion. This should check for all
492 other quoting characters, too. */
493 if (strchr (token, '\\'))
494 expand_this_token = 0;
496 /* If we should be expanding here, if we are expanding all words, or if
497 we are in a location in the string where an expansion is supposed to
498 take place, see if this word has a substitution. If it does, then do
499 the expansion. Note that we defer the alias value lookup until we
500 are sure we are expanding this token. */
503 (expand_this_token || alias_expand_all) &&
504 (alias = find_alias (token)))
511 llen = strlen (line);
513 /* +3 because we possibly add one more character below. */
514 RESIZE_MALLOCED_BUFFER (line, llen, (vlen + 3), line_len, (vlen + 50));
516 strcpy (line + llen, v);
518 if ((expand_this_token && vlen && whitespace (v[vlen - 1])) ||
526 llen = strlen (line);
527 tlen = i - real_start; /* tlen == strlen(token) */
529 RESIZE_MALLOCED_BUFFER (line, llen, (tlen + 1), line_len, (llen + tlen + 50));
531 strncpy (line + llen, string + real_start, tlen);
532 line[llen + tlen] = '\0';
537 #endif /* READLINE */