Commit | Line | Data |
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657820b8 | 1 | static char *sccsid = "@(#)exec.c 4.8 %G%"; |
c5fd306c BJ |
2 | |
3 | #include "sh.h" | |
657820b8 | 4 | #include <sys/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 | /* | |
ec1a81af | 93 | * We must do this AFTER any possible forking (like `foo` |
c5fd306c BJ |
94 | * in glob) so that this shell can still do subprocesses. |
95 | */ | |
2f2a0649 SL |
96 | #ifdef notdef |
97 | sigsys(SIGCHLD, SIG_IGN); /* sigsys for vforks sake */ | |
98 | #endif | |
99 | sigsetmask(0); | |
c5fd306c BJ |
100 | |
101 | /* | |
102 | * If no path, no words in path, or a / in the filename | |
103 | * then restrict the command search. | |
104 | */ | |
105 | if (v == 0 || v->vec[0] == 0 || slash) | |
106 | pv = justabs; | |
107 | else | |
108 | pv = v->vec; | |
109 | sav = strspl("/", *av); /* / command name for postpending */ | |
110 | #ifdef VFORK | |
111 | Vsav = sav; | |
112 | #endif | |
113 | if (havhash) | |
114 | hashval = xhash[hash(*av)]; | |
115 | i = 0; | |
116 | #ifdef VFORK | |
117 | hits++; | |
118 | #endif | |
119 | do { | |
120 | if (!slash && pv[0][0] == '/' && havhash && (hashval & (1 << (i % 8))) == 0) | |
121 | goto cont; | |
122 | if (pv[0][0] == 0 || eq(pv[0], ".")) /* don't make ./xxx */ | |
123 | texec(*av, av); | |
124 | else { | |
125 | dp = strspl(*pv, sav); | |
126 | #ifdef VFORK | |
127 | Vdp = dp; | |
128 | #endif | |
129 | texec(dp, av); | |
130 | #ifdef VFORK | |
131 | Vdp = 0; | |
132 | #endif | |
133 | xfree(dp); | |
134 | } | |
135 | #ifdef VFORK | |
136 | misses++; | |
137 | #endif | |
138 | cont: | |
139 | pv++; | |
140 | i++; | |
141 | } while (*pv); | |
142 | #ifdef VFORK | |
143 | hits--; | |
144 | #endif | |
145 | #ifdef VFORK | |
146 | Vsav = 0; | |
147 | Vav = 0; | |
148 | #endif | |
149 | xfree(sav); | |
150 | xfree(av); | |
151 | pexerr(); | |
152 | } | |
153 | ||
154 | pexerr() | |
155 | { | |
156 | ||
157 | /* Couldn't find the damn thing */ | |
158 | setname(expath); | |
159 | /* xfree(expath); */ | |
160 | if (exerr) | |
161 | bferr(exerr); | |
162 | bferr("Command not found"); | |
163 | } | |
164 | ||
165 | /* Last resort shell */ | |
166 | char *lastsh[] = { SHELLPATH, 0 }; | |
167 | ||
168 | /* | |
169 | * Execute command f, arg list t. | |
170 | * Record error message if not found. | |
171 | * Also do shell scripts here. | |
172 | */ | |
173 | texec(f, t) | |
174 | char *f; | |
175 | register char **t; | |
176 | { | |
177 | register struct varent *v; | |
178 | register char **vp; | |
179 | extern char *sys_errlist[]; | |
180 | ||
181 | execv(f, t); | |
182 | switch (errno) { | |
183 | ||
184 | case ENOEXEC: | |
185 | /* | |
186 | * If there is an alias for shell, then | |
187 | * put the words of the alias in front of the | |
188 | * argument list replacing the command name. | |
189 | * Note no interpretation of the words at this point. | |
190 | */ | |
191 | v = adrof1("shell", &aliases); | |
192 | if (v == 0) { | |
193 | #ifdef OTHERSH | |
194 | register int ff = open(f, 0); | |
195 | char ch; | |
196 | #endif | |
197 | ||
198 | vp = lastsh; | |
199 | vp[0] = adrof("shell") ? value("shell") : SHELLPATH; | |
200 | #ifdef OTHERSH | |
201 | if (ff != -1 && read(ff, &ch, 1) == 1 && ch != '#') | |
202 | vp[0] = OTHERSH; | |
203 | close(ff); | |
204 | #endif | |
205 | } else | |
206 | vp = v->vec; | |
207 | t[0] = f; | |
208 | t = blkspl(vp, t); /* Splice up the new arglst */ | |
209 | f = *t; | |
210 | execv(f, t); | |
211 | xfree((char *)t); | |
212 | /* The sky is falling, the sky is falling! */ | |
213 | ||
214 | case ENOMEM: | |
215 | Perror(f); | |
216 | ||
217 | case ENOENT: | |
218 | break; | |
219 | ||
220 | default: | |
221 | if (exerr == 0) { | |
222 | exerr = sys_errlist[errno]; | |
223 | expath = savestr(f); | |
224 | } | |
225 | } | |
226 | } | |
227 | ||
228 | execash(t, kp) | |
229 | register struct command *kp; | |
230 | { | |
231 | ||
232 | didcch++; | |
30211ec6 | 233 | rechist(); |
c5fd306c BJ |
234 | signal(SIGINT, parintr); |
235 | signal(SIGQUIT, parintr); | |
236 | signal(SIGTERM, parterm); /* if doexec loses, screw */ | |
237 | lshift(kp->t_dcom, 1); | |
238 | exiterr++; | |
239 | doexec(kp); | |
240 | /*NOTREACHED*/ | |
241 | } | |
242 | ||
243 | xechoit(t) | |
244 | char **t; | |
245 | { | |
246 | ||
247 | if (adrof("echo")) { | |
248 | flush(); | |
249 | haderr = 1; | |
250 | blkpr(t), printf("\n"); | |
251 | haderr = 0; | |
252 | } | |
253 | } | |
254 | ||
255 | dohash() | |
256 | { | |
257 | struct stat stb; | |
9363f20d KM |
258 | DIR *dirp; |
259 | register struct direct *dp; | |
260 | register int cnt; | |
c5fd306c BJ |
261 | int i = 0; |
262 | struct varent *v = adrof("path"); | |
263 | char **pv; | |
264 | ||
265 | havhash = 1; | |
266 | for (cnt = 0; cnt < HSHSIZ; cnt++) | |
267 | xhash[cnt] = 0; | |
268 | if (v == 0) | |
269 | return; | |
270 | for (pv = v->vec; *pv; pv++, i = (i + 1) % 8) { | |
271 | if (pv[0][0] != '/') | |
272 | continue; | |
9363f20d KM |
273 | dirp = opendir(*pv); |
274 | if (dirp == NULL) | |
c5fd306c | 275 | continue; |
9363f20d KM |
276 | if (fstat(dirp->dd_fd, &stb) < 0 || !isdir(stb)) { |
277 | closedir(dirp); | |
c5fd306c BJ |
278 | continue; |
279 | } | |
9363f20d KM |
280 | while ((dp = readdir(dirp)) != NULL) { |
281 | if (dp->d_ino == 0) | |
282 | continue; | |
283 | xhash[hash(dp->d_name)] |= (1 << i); | |
c5fd306c | 284 | } |
9363f20d | 285 | closedir(dirp); |
c5fd306c BJ |
286 | } |
287 | } | |
288 | ||
289 | dounhash() | |
290 | { | |
291 | ||
292 | havhash = 0; | |
293 | } | |
294 | ||
295 | #ifdef VFORK | |
296 | hashstat() | |
297 | { | |
298 | ||
299 | if (hits+misses) | |
300 | printf("%d hits, %d misses, %2d%%\n", hits, misses, 100 * hits / (hits + misses)); | |
301 | } | |
302 | #endif | |
303 | ||
304 | hash(cp) | |
305 | register char *cp; | |
306 | { | |
307 | register long hash = 0; | |
308 | int retval; | |
309 | ||
310 | while (*cp) | |
311 | hash += hash + *cp++; | |
312 | if (hash < 0) | |
313 | hash = -hash; | |
314 | retval = hash % HSHSIZ; | |
315 | return (retval); | |
316 | } |