1 /* Id */
2
3 /*
4 * Copyright (c) 2008 Nicholas Marriott <nicm@users.sourceforge.net>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/types.h>
20
21 #include <errno.h>
22 #include <pwd.h>
23 #include <stdio.h>
24 #include <string.h>
25 #include <stdlib.h>
26 #include <unistd.h>
27
28 #include "tmux.h"
29
30 /*
31 * Parse a command from a string.
32 */
33
34 int cmd_string_getc(const char *, size_t *);
35 void cmd_string_ungetc(size_t *);
36 void cmd_string_copy(char **, char *, size_t *);
37 char *cmd_string_string(const char *, size_t *, char, int);
38 char *cmd_string_variable(const char *, size_t *);
39 char *cmd_string_expand_tilde(const char *, size_t *);
40
41 int
cmd_string_getc(const char * s,size_t * p)42 cmd_string_getc(const char *s, size_t *p)
43 {
44 const char *ucs = s;
45
46 if (ucs[*p] == '\0')
47 return (EOF);
48 return (u_char)(ucs[(*p)++]);
49 }
50
51 void
cmd_string_ungetc(size_t * p)52 cmd_string_ungetc(size_t *p)
53 {
54 (*p)--;
55 }
56
57 /*
58 * Parse command string. Returns -1 on error. If returning -1, cause is error
59 * string, or NULL for empty command.
60 */
61 int
cmd_string_parse(const char * s,struct cmd_list ** cmdlist,const char * file,u_int line,char ** cause)62 cmd_string_parse(const char *s, struct cmd_list **cmdlist, const char *file,
63 u_int line, char **cause)
64 {
65 size_t p;
66 int ch, i, argc, rval;
67 char **argv, *buf, *t;
68 const char *whitespace, *equals;
69 size_t len;
70
71 argv = NULL;
72 argc = 0;
73
74 buf = NULL;
75 len = 0;
76
77 *cause = NULL;
78
79 *cmdlist = NULL;
80 rval = -1;
81
82 p = 0;
83 for (;;) {
84 ch = cmd_string_getc(s, &p);
85 switch (ch) {
86 case '\'':
87 if ((t = cmd_string_string(s, &p, '\'', 0)) == NULL)
88 goto error;
89 cmd_string_copy(&buf, t, &len);
90 break;
91 case '"':
92 if ((t = cmd_string_string(s, &p, '"', 1)) == NULL)
93 goto error;
94 cmd_string_copy(&buf, t, &len);
95 break;
96 case '$':
97 if ((t = cmd_string_variable(s, &p)) == NULL)
98 goto error;
99 cmd_string_copy(&buf, t, &len);
100 break;
101 case '#':
102 /* Comment: discard rest of line. */
103 while ((ch = cmd_string_getc(s, &p)) != EOF)
104 ;
105 /* FALLTHROUGH */
106 case EOF:
107 case ' ':
108 case '\t':
109 if (buf != NULL) {
110 buf = xrealloc(buf, 1, len + 1);
111 buf[len] = '\0';
112
113 argv = xrealloc(argv, argc + 1, sizeof *argv);
114 argv[argc++] = buf;
115
116 buf = NULL;
117 len = 0;
118 }
119
120 if (ch != EOF)
121 break;
122
123 while (argc != 0) {
124 equals = strchr(argv[0], '=');
125 whitespace = argv[0] + strcspn(argv[0], " \t");
126 if (equals == NULL || equals > whitespace)
127 break;
128 environ_put(&global_environ, argv[0]);
129 argc--;
130 memmove(argv, argv + 1, argc * (sizeof *argv));
131 }
132 if (argc == 0)
133 goto out;
134
135 *cmdlist = cmd_list_parse(argc, argv, file, line, cause);
136 if (*cmdlist == NULL)
137 goto out;
138
139 rval = 0;
140 goto out;
141 case '~':
142 if (buf == NULL) {
143 t = cmd_string_expand_tilde(s, &p);
144 if (t == NULL)
145 goto error;
146 cmd_string_copy(&buf, t, &len);
147 break;
148 }
149 /* FALLTHROUGH */
150 default:
151 if (len >= SIZE_MAX - 2)
152 goto error;
153
154 buf = xrealloc(buf, 1, len + 1);
155 buf[len++] = ch;
156 break;
157 }
158 }
159
160 error:
161 xasprintf(cause, "invalid or unknown command: %s", s);
162
163 out:
164 free(buf);
165
166 if (argv != NULL) {
167 for (i = 0; i < argc; i++)
168 free(argv[i]);
169 free(argv);
170 }
171
172 return (rval);
173 }
174
175 void
cmd_string_copy(char ** dst,char * src,size_t * len)176 cmd_string_copy(char **dst, char *src, size_t *len)
177 {
178 size_t srclen;
179
180 srclen = strlen(src);
181
182 *dst = xrealloc(*dst, 1, *len + srclen + 1);
183 strlcpy(*dst + *len, src, srclen + 1);
184
185 *len += srclen;
186 free(src);
187 }
188
189 char *
cmd_string_string(const char * s,size_t * p,char endch,int esc)190 cmd_string_string(const char *s, size_t *p, char endch, int esc)
191 {
192 int ch;
193 char *buf, *t;
194 size_t len;
195
196 buf = NULL;
197 len = 0;
198
199 while ((ch = cmd_string_getc(s, p)) != endch) {
200 switch (ch) {
201 case EOF:
202 goto error;
203 case '\\':
204 if (!esc)
205 break;
206 switch (ch = cmd_string_getc(s, p)) {
207 case EOF:
208 goto error;
209 case 'e':
210 ch = '\033';
211 break;
212 case 'r':
213 ch = '\r';
214 break;
215 case 'n':
216 ch = '\n';
217 break;
218 case 't':
219 ch = '\t';
220 break;
221 }
222 break;
223 case '$':
224 if (!esc)
225 break;
226 if ((t = cmd_string_variable(s, p)) == NULL)
227 goto error;
228 cmd_string_copy(&buf, t, &len);
229 continue;
230 }
231
232 if (len >= SIZE_MAX - 2)
233 goto error;
234 buf = xrealloc(buf, 1, len + 1);
235 buf[len++] = ch;
236 }
237
238 buf = xrealloc(buf, 1, len + 1);
239 buf[len] = '\0';
240 return (buf);
241
242 error:
243 free(buf);
244 return (NULL);
245 }
246
247 char *
cmd_string_variable(const char * s,size_t * p)248 cmd_string_variable(const char *s, size_t *p)
249 {
250 int ch, fch;
251 char *buf, *t;
252 size_t len;
253 struct environ_entry *envent;
254
255 #define cmd_string_first(ch) ((ch) == '_' || \
256 ((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z'))
257 #define cmd_string_other(ch) ((ch) == '_' || \
258 ((ch) >= 'a' && (ch) <= 'z') || ((ch) >= 'A' && (ch) <= 'Z') || \
259 ((ch) >= '0' && (ch) <= '9'))
260
261 buf = NULL;
262 len = 0;
263
264 fch = EOF;
265 switch (ch = cmd_string_getc(s, p)) {
266 case EOF:
267 goto error;
268 case '{':
269 fch = '{';
270
271 ch = cmd_string_getc(s, p);
272 if (!cmd_string_first(ch))
273 goto error;
274 /* FALLTHROUGH */
275 default:
276 if (!cmd_string_first(ch)) {
277 xasprintf(&t, "$%c", ch);
278 return (t);
279 }
280
281 buf = xrealloc(buf, 1, len + 1);
282 buf[len++] = ch;
283
284 for (;;) {
285 ch = cmd_string_getc(s, p);
286 if (ch == EOF || !cmd_string_other(ch))
287 break;
288 else {
289 if (len >= SIZE_MAX - 3)
290 goto error;
291 buf = xrealloc(buf, 1, len + 1);
292 buf[len++] = ch;
293 }
294 }
295 }
296
297 if (fch == '{' && ch != '}')
298 goto error;
299 if (ch != EOF && fch != '{')
300 cmd_string_ungetc(p); /* ch */
301
302 buf = xrealloc(buf, 1, len + 1);
303 buf[len] = '\0';
304
305 envent = environ_find(&global_environ, buf);
306 free(buf);
307 if (envent == NULL)
308 return (xstrdup(""));
309 return (xstrdup(envent->value));
310
311 error:
312 free(buf);
313 return (NULL);
314 }
315
316 char *
cmd_string_expand_tilde(const char * s,size_t * p)317 cmd_string_expand_tilde(const char *s, size_t *p)
318 {
319 struct passwd *pw;
320 struct environ_entry *envent;
321 char *home, *path, *user, *cp;
322 int last;
323
324 home = NULL;
325
326 last = cmd_string_getc(s, p);
327 if (last == EOF || last == '/' || last == ' '|| last == '\t') {
328 envent = environ_find(&global_environ, "HOME");
329 if (envent != NULL && *envent->value != '\0')
330 home = envent->value;
331 else if ((pw = getpwuid(getuid())) != NULL)
332 home = pw->pw_dir;
333 } else {
334 cmd_string_ungetc(p);
335
336 cp = user = xmalloc(strlen(s));
337 for (;;) {
338 last = cmd_string_getc(s, p);
339 if (last == EOF || last == '/' || last == ' '|| last == '\t')
340 break;
341 *cp++ = last;
342 }
343 *cp = '\0';
344
345 if ((pw = getpwnam(user)) != NULL)
346 home = pw->pw_dir;
347 free(user);
348 }
349
350 if (home == NULL)
351 return (NULL);
352
353 if (last != EOF)
354 xasprintf(&path, "%s%c", home, last);
355 else
356 xasprintf(&path, "%s", home);
357 return (path);
358 }
359