1 /* expand_path.c -- expand environmental variables in passed in string
2 *
3 * Copyright (C) 1995-2005 The Free Software Foundation, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2, or (at your option)
8 * any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * The main routine is expand_path(), it is the routine that handles
16 * the '~' character in four forms:
17 * ~name
18 * ~name/
19 * ~/
20 * ~
21 * and handles environment variables contained within the pathname
22 * which are defined by:
23 * ${var_name} (var_name is the name of the environ variable)
24 * $var_name (var_name ends w/ non-alphanumeric char other than '_')
25 */
26
27 #include "cvs.h"
28 #include <sys/types.h>
29
30 static char *expand_variable PROTO((const char *env, const char *file,
31 int line));
32
33
34
35 /* User variables. */
36
37 List *variable_list = NULL;
38
39 static void variable_delproc PROTO ((Node *));
40
41 static void
variable_delproc(node)42 variable_delproc (node)
43 Node *node;
44 {
45 free (node->data);
46 }
47
48 /* Currently used by -s option; we might want a way to set user
49 variables in a file in the $CVSROOT/CVSROOT directory too. */
50
51 void
variable_set(nameval)52 variable_set (nameval)
53 char *nameval;
54 {
55 char *p;
56 char *name;
57 Node *node;
58
59 p = nameval;
60 while (isalnum ((unsigned char) *p) || *p == '_')
61 ++p;
62 if (*p != '=')
63 error (1, 0, "illegal character in user variable name in %s", nameval);
64 if (p == nameval)
65 error (1, 0, "empty user variable name in %s", nameval);
66 name = xmalloc (p - nameval + 1);
67 strncpy (name, nameval, p - nameval);
68 name[p - nameval] = '\0';
69 /* Make p point to the value. */
70 ++p;
71 if (strchr (p, '\012') != NULL)
72 error (1, 0, "linefeed in user variable value in %s", nameval);
73
74 if (variable_list == NULL)
75 variable_list = getlist ();
76
77 node = findnode (variable_list, name);
78 if (node == NULL)
79 {
80 node = getnode ();
81 node->type = VARIABLE;
82 node->delproc = variable_delproc;
83 node->key = name;
84 node->data = xstrdup (p);
85 (void) addnode (variable_list, node);
86 }
87 else
88 {
89 /* Replace the old value. For example, this means that -s
90 options on the command line override ones from .cvsrc. */
91 free (node->data);
92 node->data = xstrdup (p);
93 free (name);
94 }
95 }
96
97
98
99 /* This routine will expand the pathname to account for ~ and $
100 characters as described above. Returns a pointer to a newly
101 malloc'd string. If an error occurs, an error message is printed
102 via error() and NULL is returned. FILE and LINE are the filename
103 and linenumber to include in the error message. FILE must point
104 to something; LINE can be zero to indicate the line number is not
105 known. */
106 char *
expand_path(name,file,line)107 expand_path (name, file, line)
108 const char *name;
109 const char *file;
110 int line;
111 {
112 size_t s, d, p;
113 char *e;
114
115 char *mybuf = NULL;
116 size_t mybuf_size = 0;
117 char *buf = NULL;
118 size_t buf_size = 0;
119
120 char *result;
121
122 /* Sorry this routine is so ugly; it is a head-on collision
123 between the `traditional' unix *d++ style and the need to
124 dynamically allocate. It would be much cleaner (and probably
125 faster, not that this is a bottleneck for CVS) with more use of
126 strcpy & friends, but I haven't taken the effort to rewrite it
127 thusly. */
128
129 /* First copy from NAME to MYBUF, expanding $<foo> as we go. */
130 s = d = 0;
131 while (name[s] != '\0')
132 {
133 if (name[s] == '$')
134 {
135 p = d;
136 if (name[++s] == '{')
137 {
138 while (name[++s] != '}' && name[s] != '\0')
139 {
140 expand_string (&mybuf, &mybuf_size, p + 1);
141 mybuf[p++] = name[s];
142 }
143 if (name[s] != '\0') ++s;
144 }
145 else
146 {
147 while (isalnum ((unsigned char) name[s]) || name[s] == '_')
148 {
149 expand_string (&mybuf, &mybuf_size, p + 1);
150 mybuf[p++] = name[s++];
151 }
152 }
153 expand_string (&mybuf, &mybuf_size, p + 1);
154 mybuf[p] = '\0';
155 e = expand_variable (mybuf + d, file, line);
156
157 if (e)
158 {
159 p = strlen(e);
160 expand_string (&mybuf, &mybuf_size, d + p);
161 memcpy(mybuf + d, e, p);
162 d += p;
163 }
164 else
165 /* expand_variable has already printed an error message. */
166 goto error_exit;
167 }
168 else
169 {
170 expand_string (&mybuf, &mybuf_size, d + 1);
171 mybuf[d++] = name[s++];
172 }
173 }
174 expand_string (&mybuf, &mybuf_size, d + 1);
175 mybuf[d++] = '\0';
176
177 /* Then copy from MYBUF to BUF, expanding ~. */
178 s = d = 0;
179 /* If you don't want ~username ~/ to be expanded simply remove
180 * This entire if statement including the else portion
181 */
182 if (mybuf[s] == '~')
183 {
184 p = d;
185 while (mybuf[++s] != '/' && mybuf[s] != '\0')
186 {
187 expand_string (&buf, &buf_size, p + 1);
188 buf[p++] = name[s];
189 }
190 expand_string (&buf, &buf_size, p + 1);
191 buf[p] = '\0';
192
193 if (p == d)
194 e = get_homedir ();
195 else
196 {
197 #ifdef GETPWNAM_MISSING
198 if (line != 0)
199 error (0, 0,
200 "%s:%d:tilde expansion not supported on this system",
201 file, line);
202 else
203 error (0, 0, "%s:tilde expansion not supported on this system",
204 file);
205 goto error_exit;
206 #else
207 struct passwd *ps;
208 ps = getpwnam (buf + d);
209 if (ps == NULL)
210 {
211 if (line != 0)
212 error (0, 0, "%s:%d: no such user %s",
213 file, line, buf + d);
214 else
215 error (0, 0, "%s: no such user %s", file, buf + d);
216 goto error_exit;
217 }
218 e = ps->pw_dir;
219 #endif
220 }
221 if (e == NULL)
222 error (1, 0, "cannot find home directory");
223
224 p = strlen(e);
225 expand_string (&buf, &buf_size, d + p);
226 memcpy(buf + d, e, p);
227 d += p;
228 }
229 /* Kill up to here */
230 p = strlen(mybuf + s) + 1;
231 expand_string (&buf, &buf_size, d + p);
232 memcpy(buf + d, mybuf + s, p);
233
234 /* OK, buf contains the value we want to return. Clean up and return
235 it. */
236 free (mybuf);
237 /* Save a little memory with xstrdup; buf will tend to allocate
238 more than it needs to. */
239 result = xstrdup (buf);
240 free (buf);
241 return result;
242
243 error_exit:
244 if (mybuf != NULL)
245 free (mybuf);
246 if (buf != NULL)
247 free (buf);
248 return NULL;
249 }
250
251 static char *
expand_variable(name,file,line)252 expand_variable (name, file, line)
253 const char *name;
254 const char *file;
255 int line;
256 {
257 if (strcmp (name, CVSROOT_ENV) == 0)
258 return current_parsed_root->directory;
259 else if (strcmp (name, "RCSBIN") == 0)
260 {
261 error (0, 0, "RCSBIN internal variable is no longer supported");
262 return NULL;
263 }
264 else if (strcmp (name, EDITOR1_ENV) == 0)
265 return Editor;
266 else if (strcmp (name, EDITOR2_ENV) == 0)
267 return Editor;
268 else if (strcmp (name, EDITOR3_ENV) == 0)
269 return Editor;
270 else if (strcmp (name, "USER") == 0)
271 return getcaller ();
272 else if (isalpha ((unsigned char) name[0]))
273 {
274 /* These names are reserved for future versions of CVS,
275 so that is why it is an error. */
276 if (line != 0)
277 error (0, 0, "%s:%d: no such internal variable $%s",
278 file, line, name);
279 else
280 error (0, 0, "%s: no such internal variable $%s",
281 file, name);
282 return NULL;
283 }
284 else if (name[0] == '=')
285 {
286 Node *node;
287 /* Crazy syntax for a user variable. But we want
288 *something* that lets the user name a user variable
289 anything he wants, without interference from
290 (existing or future) internal variables. */
291 node = findnode (variable_list, name + 1);
292 if (node == NULL)
293 {
294 if (line != 0)
295 error (0, 0, "%s:%d: no such user variable ${%s}",
296 file, line, name);
297 else
298 error (0, 0, "%s: no such user variable ${%s}",
299 file, name);
300 return NULL;
301 }
302 return node->data;
303 }
304 else
305 {
306 /* It is an unrecognized character. We return an error to
307 reserve these for future versions of CVS; it is plausible
308 that various crazy syntaxes might be invented for inserting
309 information about revisions, branches, etc. */
310 if (line != 0)
311 error (0, 0, "%s:%d: unrecognized variable syntax %s",
312 file, line, name);
313 else
314 error (0, 0, "%s: unrecognized variable syntax %s",
315 file, name);
316 return NULL;
317 }
318 }
319