Commit | Line | Data |
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ea775389 | 1 | static char *sccsid = "@(#)exec.c 4.5 %G%"; |
c5fd306c BJ |
2 | |
3 | #include "sh.h" | |
3d9f6a35 | 4 | #include <dir.h> |
c5fd306c BJ |
5 | |
6 | /* | |
7 | * C shell | |
8 | */ | |
9 | ||
10 | /* | |
11 | * System level search and execute of a command. | |
12 | * We look in each directory for the specified command name. | |
13 | * If the name contains a '/' then we execute only the full path name. | |
14 | * If there is no search path then we execute only full path names. | |
15 | */ | |
16 | ||
17 | /* | |
18 | * As we search for the command we note the first non-trivial error | |
19 | * message for presentation to the user. This allows us often | |
20 | * to show that a file has the wrong mode/no access when the file | |
21 | * is not in the last component of the search path, so we must | |
22 | * go on after first detecting the error. | |
23 | */ | |
24 | char *exerr; /* Execution error message */ | |
25 | char *expath; /* Path for exerr */ | |
26 | ||
27 | /* | |
28 | * Xhash is an array of HSHSIZ chars, which are used to hash execs. | |
29 | * If it is allocated, then to tell whether ``name'' is (possibly) | |
30 | * present in the i'th component of the variable path, you look at | |
31 | * the i'th bit of xhash[hash("name")]. This is setup automatically | |
32 | * after .login is executed, and recomputed whenever ``path'' is | |
33 | * changed. | |
34 | */ | |
35 | int havhash; | |
36 | #define HSHSIZ 511 | |
37 | char xhash[HSHSIZ]; | |
38 | #ifdef VFORK | |
39 | int hits, misses; | |
40 | #endif | |
41 | ||
42 | /* Dummy search path for just absolute search when no path */ | |
43 | char *justabs[] = { "", 0 }; | |
44 | ||
45 | doexec(t) | |
46 | register struct command *t; | |
47 | { | |
48 | char *sav; | |
49 | register char *dp, **pv, **av; | |
50 | register struct varent *v; | |
51 | bool slash = any('/', t->t_dcom[0]); | |
52 | int hashval, i; | |
53 | char *blk[2]; | |
54 | ||
55 | /* | |
56 | * Glob the command name. If this does anything, then we | |
57 | * will execute the command only relative to ".". One special | |
58 | * case: if there is no PATH, then we execute only commands | |
59 | * which start with '/'. | |
60 | */ | |
61 | dp = globone(t->t_dcom[0]); | |
62 | sav = t->t_dcom[0]; | |
63 | exerr = 0; expath = t->t_dcom[0] = dp; | |
64 | xfree(sav); | |
65 | v = adrof("path"); | |
66 | if (v == 0 && expath[0] != '/') | |
67 | pexerr(); | |
68 | slash |= gflag; | |
69 | ||
70 | /* | |
71 | * Glob the argument list, if necessary. | |
72 | * Otherwise trim off the quote bits. | |
73 | */ | |
74 | gflag = 0; av = &t->t_dcom[1]; | |
75 | rscan(av, tglob); | |
76 | if (gflag) { | |
77 | av = glob(av); | |
78 | if (av == 0) | |
79 | error("No match"); | |
80 | } | |
81 | blk[0] = t->t_dcom[0]; | |
82 | blk[1] = 0; | |
83 | av = blkspl(blk, av); | |
84 | #ifdef VFORK | |
85 | Vav = av; | |
86 | #endif | |
87 | scan(av, trim); | |
88 | ||
89 | xechoit(av); /* Echo command if -x */ | |
90 | closech(); /* Close random fd's */ | |
91 | ||
92 | /* | |
93 | * We must do this after any possible forking (like `foo` | |
94 | * in glob) so that this shell can still do subprocesses. | |
95 | */ | |
96 | sigsys(SIGCHLD, SIG_IGN); /* sigsys for vforks sake */ | |
97 | ||
98 | /* | |
99 | * If no path, no words in path, or a / in the filename | |
100 | * then restrict the command search. | |
101 | */ | |
102 | if (v == 0 || v->vec[0] == 0 || slash) | |
103 | pv = justabs; | |
104 | else | |
105 | pv = v->vec; | |
106 | sav = strspl("/", *av); /* / command name for postpending */ | |
107 | #ifdef VFORK | |
108 | Vsav = sav; | |
109 | #endif | |
110 | if (havhash) | |
111 | hashval = xhash[hash(*av)]; | |
112 | i = 0; | |
113 | #ifdef VFORK | |
114 | hits++; | |
115 | #endif | |
116 | do { | |
117 | if (!slash && pv[0][0] == '/' && havhash && (hashval & (1 << (i % 8))) == 0) | |
118 | goto cont; | |
119 | if (pv[0][0] == 0 || eq(pv[0], ".")) /* don't make ./xxx */ | |
120 | texec(*av, av); | |
121 | else { | |
122 | dp = strspl(*pv, sav); | |
123 | #ifdef VFORK | |
124 | Vdp = dp; | |
125 | #endif | |
126 | texec(dp, av); | |
127 | #ifdef VFORK | |
128 | Vdp = 0; | |
129 | #endif | |
130 | xfree(dp); | |
131 | } | |
132 | #ifdef VFORK | |
133 | misses++; | |
134 | #endif | |
135 | cont: | |
136 | pv++; | |
137 | i++; | |
138 | } while (*pv); | |
139 | #ifdef VFORK | |
140 | hits--; | |
141 | #endif | |
142 | #ifdef VFORK | |
143 | Vsav = 0; | |
144 | Vav = 0; | |
145 | #endif | |
146 | xfree(sav); | |
147 | xfree(av); | |
148 | pexerr(); | |
149 | } | |
150 | ||
151 | pexerr() | |
152 | { | |
153 | ||
154 | /* Couldn't find the damn thing */ | |
155 | setname(expath); | |
156 | /* xfree(expath); */ | |
157 | if (exerr) | |
158 | bferr(exerr); | |
159 | bferr("Command not found"); | |
160 | } | |
161 | ||
162 | /* Last resort shell */ | |
163 | char *lastsh[] = { SHELLPATH, 0 }; | |
164 | ||
165 | /* | |
166 | * Execute command f, arg list t. | |
167 | * Record error message if not found. | |
168 | * Also do shell scripts here. | |
169 | */ | |
170 | texec(f, t) | |
171 | char *f; | |
172 | register char **t; | |
173 | { | |
174 | register struct varent *v; | |
175 | register char **vp; | |
176 | extern char *sys_errlist[]; | |
177 | ||
178 | execv(f, t); | |
179 | switch (errno) { | |
180 | ||
181 | case ENOEXEC: | |
182 | /* | |
183 | * If there is an alias for shell, then | |
184 | * put the words of the alias in front of the | |
185 | * argument list replacing the command name. | |
186 | * Note no interpretation of the words at this point. | |
187 | */ | |
188 | v = adrof1("shell", &aliases); | |
189 | if (v == 0) { | |
190 | #ifdef OTHERSH | |
191 | register int ff = open(f, 0); | |
192 | char ch; | |
193 | #endif | |
194 | ||
195 | vp = lastsh; | |
196 | vp[0] = adrof("shell") ? value("shell") : SHELLPATH; | |
197 | #ifdef OTHERSH | |
198 | if (ff != -1 && read(ff, &ch, 1) == 1 && ch != '#') | |
199 | vp[0] = OTHERSH; | |
200 | close(ff); | |
201 | #endif | |
202 | } else | |
203 | vp = v->vec; | |
204 | t[0] = f; | |
205 | t = blkspl(vp, t); /* Splice up the new arglst */ | |
206 | f = *t; | |
207 | execv(f, t); | |
208 | xfree((char *)t); | |
209 | /* The sky is falling, the sky is falling! */ | |
210 | ||
211 | case ENOMEM: | |
212 | Perror(f); | |
213 | ||
214 | case ENOENT: | |
215 | break; | |
216 | ||
217 | default: | |
218 | if (exerr == 0) { | |
219 | exerr = sys_errlist[errno]; | |
220 | expath = savestr(f); | |
221 | } | |
222 | } | |
223 | } | |
224 | ||
225 | execash(t, kp) | |
226 | register struct command *kp; | |
227 | { | |
228 | ||
229 | didcch++; | |
30211ec6 | 230 | rechist(); |
c5fd306c BJ |
231 | signal(SIGINT, parintr); |
232 | signal(SIGQUIT, parintr); | |
233 | signal(SIGTERM, parterm); /* if doexec loses, screw */ | |
234 | lshift(kp->t_dcom, 1); | |
235 | exiterr++; | |
236 | doexec(kp); | |
237 | /*NOTREACHED*/ | |
238 | } | |
239 | ||
240 | xechoit(t) | |
241 | char **t; | |
242 | { | |
243 | ||
244 | if (adrof("echo")) { | |
245 | flush(); | |
246 | haderr = 1; | |
247 | blkpr(t), printf("\n"); | |
248 | haderr = 0; | |
249 | } | |
250 | } | |
251 | ||
252 | dohash() | |
253 | { | |
254 | struct stat stb; | |
9363f20d KM |
255 | DIR *dirp; |
256 | register struct direct *dp; | |
257 | register int cnt; | |
c5fd306c BJ |
258 | int i = 0; |
259 | struct varent *v = adrof("path"); | |
260 | char **pv; | |
261 | ||
262 | havhash = 1; | |
263 | for (cnt = 0; cnt < HSHSIZ; cnt++) | |
264 | xhash[cnt] = 0; | |
265 | if (v == 0) | |
266 | return; | |
267 | for (pv = v->vec; *pv; pv++, i = (i + 1) % 8) { | |
268 | if (pv[0][0] != '/') | |
269 | continue; | |
9363f20d KM |
270 | dirp = opendir(*pv); |
271 | if (dirp == NULL) | |
c5fd306c | 272 | continue; |
9363f20d KM |
273 | if (fstat(dirp->dd_fd, &stb) < 0 || !isdir(stb)) { |
274 | closedir(dirp); | |
c5fd306c BJ |
275 | continue; |
276 | } | |
9363f20d KM |
277 | while ((dp = readdir(dirp)) != NULL) { |
278 | if (dp->d_ino == 0) | |
279 | continue; | |
280 | xhash[hash(dp->d_name)] |= (1 << i); | |
c5fd306c | 281 | } |
9363f20d | 282 | closedir(dirp); |
c5fd306c BJ |
283 | } |
284 | } | |
285 | ||
286 | dounhash() | |
287 | { | |
288 | ||
289 | havhash = 0; | |
290 | } | |
291 | ||
292 | #ifdef VFORK | |
293 | hashstat() | |
294 | { | |
295 | ||
296 | if (hits+misses) | |
297 | printf("%d hits, %d misses, %2d%%\n", hits, misses, 100 * hits / (hits + misses)); | |
298 | } | |
299 | #endif | |
300 | ||
301 | hash(cp) | |
302 | register char *cp; | |
303 | { | |
304 | register long hash = 0; | |
305 | int retval; | |
306 | ||
307 | while (*cp) | |
308 | hash += hash + *cp++; | |
309 | if (hash < 0) | |
310 | hash = -hash; | |
311 | retval = hash % HSHSIZ; | |
312 | return (retval); | |
313 | } |