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git.ipfire.org Git - thirdparty/bash.git/blob - alias.c
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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 return (aliases
->nentries
);
159 /* Delete all aliases. */
161 delete_all_aliases ()
166 flush_hash_table (aliases
, free_alias_data
);
168 aliases
= (HASH_TABLE
*)NULL
;
171 /* Return an array of aliases that satisfy the conditions tested by FUNCTION.
172 If FUNCTION is NULL, return all aliases. */
174 map_over_aliases (function
)
178 register BUCKET_CONTENTS
*tlist
;
179 alias_t
*alias
, **list
;
180 int list_index
, list_size
;
182 list
= (alias_t
**)NULL
;
183 for (i
= list_index
= list_size
= 0; i
< aliases
->nbuckets
; i
++)
185 tlist
= get_hash_bucket (i
, aliases
);
189 alias
= (alias_t
*)tlist
->data
;
191 if (!function
|| (*function
) (alias
))
193 if (list_index
+ 1 >= list_size
)
195 xrealloc ((char *)list
, (list_size
+= 20) * sizeof (alias_t
*));
197 list
[list_index
++] = alias
;
198 list
[list_index
] = (alias_t
*)NULL
;
210 qsort (array
, array_len ((char **)array
), sizeof (alias_t
*), qsort_alias_compare
);
214 qsort_alias_compare (as1
, as2
)
215 alias_t
**as1
, **as2
;
219 if ((result
= (*as1
)->name
[0] - (*as2
)->name
[0]) == 0)
220 result
= strcmp ((*as1
)->name
, (*as2
)->name
);
225 /* Return a sorted list of all defined aliases */
232 return ((alias_t
**)NULL
);
234 list
= map_over_aliases ((Function
*)NULL
);
241 alias_expand_word (s
)
247 return (r
? savestring (r
->value
) : (char *)NULL
);
250 /* Return non-zero if CHARACTER is a member of the class of characters
251 that are self-delimiting in the shell (this really means that these
252 characters delimit tokens). */
253 #define self_delimiting(character) (member ((character), " \t\n\r;|&()"))
255 /* Return non-zero if CHARACTER is a member of the class of characters
256 that delimit commands in the shell. */
257 #define command_separator(character) (member ((character), "\r\n;|&("))
259 /* If this is 1, we are checking the next token read for alias expansion
260 because it is the first word in a command. */
261 static int command_word
;
263 /* This is for skipping quoted strings in alias expansions. */
264 #define quote_char(c) (((c) == '\'') || ((c) == '"'))
266 /* Consume a quoted string from STRING, starting at string[START] (so
267 string[START] is the opening quote character), and return the index
268 of the closing quote character matching the opening quote character.
269 This handles single matching pairs of unquoted quotes; it could afford
270 to be a little smarter... This skips words between balanced pairs of
271 quotes, words where the first character is quoted with a `\', and other
272 backslash-escaped characters. */
275 skipquotes (string
, start
)
280 int delimiter
= string
[start
];
282 /* i starts at START + 1 because string[START] is the opening quote
284 for (i
= start
+ 1 ; string
[i
] ; i
++)
286 if (string
[i
] == '\\')
288 i
++; /* skip backslash-quoted quote characters, too */
292 if (string
[i
] == delimiter
)
298 /* Skip the white space and any quoted characters in STRING, starting at
299 START. Return the new index into STRING, after zero or more characters
300 have been skipped. */
302 skipws (string
, start
)
307 int pass_next
, backslash_quoted_word
, peekc
;
309 /* skip quoted strings, in ' or ", and words in which a character is quoted
311 backslash_quoted_word
= pass_next
= 0;
313 /* Skip leading whitespace (or separator characters), and quoted words.
314 But save it in the output. */
316 for (i
= start
; string
[i
]; i
++)
324 if (whitespace (string
[i
]))
326 backslash_quoted_word
= 0; /* we are no longer in a backslash-quoted word */
330 if (string
[i
] == '\\')
333 if (isletter (peekc
))
334 backslash_quoted_word
++; /* this is a backslash-quoted word */
340 /* This only handles single pairs of non-escaped quotes. This
341 overloads backslash_quoted_word to also mean that a word like
342 ""f is being scanned, so that the quotes will inhibit any expansion
344 if (quote_char(string
[i
]))
346 i
= skipquotes (string
, i
);
347 /* This could be a line that contains a single quote character,
348 in which case skipquotes () terminates with string[i] == '\0'
349 (the end of the string). Check for that here. */
350 if (string
[i
] == '\0')
353 peekc
= string
[i
+ 1];
354 if (isletter (peekc
))
355 backslash_quoted_word
++;
359 /* If we're in the middle of some kind of quoted word, let it
361 if (backslash_quoted_word
)
364 /* If this character is a shell command separator, then set a hint for
365 alias_expand that the next token is the first word in a command. */
367 if (command_separator (string
[i
]))
377 /* Characters that may appear in a token. Basically, anything except white
378 space and a token separator. */
379 #define token_char(c) (!((whitespace (string[i]) || self_delimiting (string[i]))))
381 /* Read from START in STRING until the next separator character, and return
382 the index of that separator. Skip backslash-quoted characters. Call
383 skipquotes () for quoted strings in the middle or at the end of tokens,
384 so all characters show up (e.g. foo'' and foo""bar) */
386 rd_token (string
, start
)
392 /* From here to next separator character is a token. */
393 for (i
= start
; string
[i
] && token_char (string
[i
]); i
++)
395 if (string
[i
] == '\\')
397 i
++; /* skip backslash-escaped character */
401 /* If this character is a quote character, we want to call skipquotes
402 to get the whole quoted portion as part of this word. That word
403 will not generally match an alias, even if te unquoted word would
404 have. The presence of the quotes in the token serves then to
405 inhibit expansion. */
406 if (quote_char (string
[i
]))
408 i
= skipquotes (string
, i
);
409 /* Now string[i] is the matching quote character, and the
410 quoted portion of the token has been scanned. */
417 /* Return a new line, with any aliases substituted. */
419 alias_expand (string
)
422 int line_len
= 1 + strlen (string
);
423 char *line
= (char *)xmalloc (line_len
);
424 register int i
, j
, start
;
425 char *token
= xmalloc (line_len
);
426 int tl
, real_start
, expand_next
, expand_this_token
;
431 command_word
= 1; /* initialized to expand the first word on the line */
433 /* Each time through the loop we find the next word in line. If it
434 has an alias, substitute
435 the alias value. If the value ends in ` ', then try again
436 with the next word. Else, if there is no value, or if
437 the value does not end in space, we are done. */
445 /* Skip white space and quoted characters */
446 i
= skipws (string
, start
);
448 if (start
== i
&& string
[i
] == '\0')
454 /* copy the just-skipped characters into the output string,
455 expanding it if there is not enough room. */
457 tl
= i
- start
; /* number of characters just skipped */
458 RESIZE_MALLOCED_BUFFER (line
, j
, (tl
+ 1), line_len
, (tl
+ 50));
459 strncpy (line
+ j
, string
+ start
, tl
);
464 command_word
= command_word
|| (command_separator (string
[i
]));
465 expand_this_token
= (command_word
|| expand_next
);
468 /* Read the next token, and copy it into TOKEN. */
470 i
= rd_token (string
, start
);
472 tl
= i
- start
; /* token length */
474 /* If tl == 0, but we're not at the end of the string, then we have a
475 single-character token, probably a delimiter */
476 if (tl
== 0 && string
[i
] != '\0')
479 i
++; /* move past it */
482 strncpy (token
, string
+ start
, tl
);
485 /* If there is a backslash-escaped character quoted in TOKEN,
486 then we don't do alias expansion. This should check for all
487 other quoting characters, too. */
488 if (strchr (token
, '\\'))
489 expand_this_token
= 0;
491 /* If we should be expanding here, if we are expanding all words, or if
492 we are in a location in the string where an expansion is supposed to
493 take place, see if this word has a substitution. If it does, then do
494 the expansion. Note that we defer the alias value lookup until we
495 are sure we are expanding this token. */
498 (expand_this_token
|| alias_expand_all
) &&
499 (alias
= find_alias (token
)))
506 llen
= strlen (line
);
508 /* +3 because we possibly add one more character below. */
509 RESIZE_MALLOCED_BUFFER (line
, llen
, (vlen
+ 3), line_len
, (vlen
+ 50));
511 strcpy (line
+ llen
, v
);
513 if ((expand_this_token
&& vlen
&& whitespace (v
[vlen
- 1])) ||
521 llen
= strlen (line
);
522 tlen
= i
- real_start
; /* tlen == strlen(token) */
524 RESIZE_MALLOCED_BUFFER (line
, llen
, (tlen
+ 1), line_len
, (llen
+ tlen
+ 50));
526 strncpy (line
+ llen
, string
+ real_start
, tlen
);
527 line
[llen
+ tlen
] = '\0';