1 #define NOPLAN9DEFINES
2 #include	"mk.h"
3 #include	<sys/wait.h>
4 #include	<signal.h>
5 #include	<sys/stat.h>
6 #include	<sys/time.h>
7 
8 char	*shell = "/bin/sh";
9 char	*shellname = "sh";
10 
11 extern char **environ;
12 
13 static void
14 mkperror(char *s)
15 {
16 	fprint(2, "%s: %r\n", s);
17 }
18 
19 void
20 readenv(void)
21 {
22 	char **p, *s;
23 	Word *w;
24 
25 	for(p = environ; *p; p++){
26 /* rsc 5/5/2004 -- This misparses fn#cd={whatever}
27 		s = shname(*p);
28 		if(*s == '=') {
29 			*s = 0;
30 			w = newword(s+1);
31 		} else
32 			w = newword("");
33 */
34 		s = strchr(*p, '=');
35 		if(s){
36 			*s = 0;
37 			w = newword(s+1);
38 		} else
39 			w = newword("");
40 		if (symlook(*p, S_INTERNAL, 0))
41 			continue;
42 		s = strdup(*p);
43 		setvar(s, (void *)w);
44 		symlook(s, S_EXPORTED, (void*)"")->u.ptr = "";
45 	}
46 }
47 
48 /*
49  *	done on child side of fork, so parent's env is not affected
50  *	and we don't care about freeing memory because we're going
51  *	to exec immediately after this.
52  */
53 void
54 exportenv(Envy *e, Shell *sh)
55 {
56 	int w, n;
57 	char **p;
58 	Envy *e1;
59 	static char buf[16384];
60 
61 	n = 0;
62 	for(e1 = e; e1->name; e1++)
63 		n++;
64 	p = Malloc((n+1)*sizeof(char*));
65 	w = 0;
66 	for(; e->name; e++) {
67 		if(sh == &rcshell && (e->values == 0 || e->values->s == 0 || e->values->s[0] == 0))
68 			continue; /* do not write empty string for empty list */
69 		if(e->values)
70 			snprint(buf, sizeof buf, "%s=%s", e->name,  wtos(e->values, sh->iws));
71 		else
72 			snprint(buf, sizeof buf, "%s=", e->name);
73 		p[w++] = strdup(buf);
74 	}
75 	p[w] = 0;
76 	environ = p;
77 }
78 
79 int
80 waitfor(char *msg)
81 {
82 	int status;
83 	int pid;
84 
85 	*msg = 0;
86 	pid = wait(&status);
87 	if(pid > 0) {
88 		if(status&0x7f) {
89 			if(status&0x80)
90 				snprint(msg, ERRMAX, "signal %d, core dumped", status&0x7f);
91 			else
92 				snprint(msg, ERRMAX, "signal %d", status&0x7f);
93 		} else if(status&0xff00)
94 			snprint(msg, ERRMAX, "exit(%d)", (status>>8)&0xff);
95 	}
96 	return pid;
97 }
98 
99 void
100 expunge(int pid, char *msg)
101 {
102 	if(strcmp(msg, "interrupt"))
103 		kill(pid, SIGINT);
104 	else
105 		kill(pid, SIGHUP);
106 }
107 
108 int mypid;
109 
110 int
111 shargv(Word *cmd, int extra, char ***pargv)
112 {
113 	char **argv;
114 	int i, n;
115 	Word *w;
116 
117 	n = 0;
118 	for(w=cmd; w; w=w->next)
119 		n++;
120 
121 	argv = Malloc((n+extra+1)*sizeof(argv[0]));
122 	i = 0;
123 	for(w=cmd; w; w=w->next)
124 		argv[i++] = w->s;
125 	argv[n] = 0;
126 	*pargv = argv;
127 	return n;
128 }
129 
130 int
131 execsh(char *args, char *cmd, Bufblock *buf, Envy *e, Shell *sh, Word *shellcmd)
132 {
133 	char *p, **argv;
134 	int tot, n, pid, in[2], out[2];
135 
136 	if(buf && pipe(out) < 0){
137 		mkperror("pipe");
138 		Exit();
139 	}
140 	pid = fork();
141 	mypid = getpid();
142 	if(pid < 0){
143 		mkperror("mk fork");
144 		Exit();
145 	}
146 	if(pid == 0){
147 		if(buf)
148 			close(out[0]);
149 		if(pipe(in) < 0){
150 			mkperror("pipe");
151 			Exit();
152 		}
153 		pid = fork();
154 		if(pid < 0){
155 			mkperror("mk fork");
156 			Exit();
157 		}
158 		if(pid != 0){
159 			dup2(in[0], 0);
160 			if(buf){
161 				dup2(out[1], 1);
162 				close(out[1]);
163 			}
164 			close(in[0]);
165 			close(in[1]);
166 			if (e)
167 				exportenv(e, sh);
168 			n = shargv(shellcmd, 1, &argv);
169 			argv[n++] = args;
170 			argv[n] = 0;
171 			execvp(argv[0], argv);
172 			mkperror(shell);
173 			_exit(1);
174 		}
175 		close(out[1]);
176 		close(in[0]);
177 		if(DEBUG(D_EXEC))
178 			fprint(1, "starting: %s\n", cmd);
179 		p = cmd+strlen(cmd);
180 		while(cmd < p){
181 			n = write(in[1], cmd, p-cmd);
182 			if(n < 0)
183 				break;
184 			cmd += n;
185 		}
186 		close(in[1]);
187 		_exit(0);
188 	}
189 	if(buf){
190 		close(out[1]);
191 		tot = 0;
192 		for(;;){
193 			if (buf->current >= buf->end)
194 				growbuf(buf);
195 			n = read(out[0], buf->current, buf->end-buf->current);
196 			if(n <= 0)
197 				break;
198 			buf->current += n;
199 			tot += n;
200 		}
201 		if (tot && buf->current[-1] == '\n')
202 			buf->current--;
203 		close(out[0]);
204 	}
205 	return pid;
206 }
207 
208 int
209 pipecmd(char *cmd, Envy *e, int *fd, Shell *sh, Word *shellcmd)
210 {
211 	int pid, pfd[2];
212 	int n;
213 	char **argv;
214 
215 	if(DEBUG(D_EXEC))
216 		fprint(1, "pipecmd='%s'\n", cmd);/**/
217 
218 	if(fd && pipe(pfd) < 0){
219 		mkperror("pipe");
220 		Exit();
221 	}
222 	pid = fork();
223 	if(pid < 0){
224 		mkperror("mk fork");
225 		Exit();
226 	}
227 	if(pid == 0){
228 		if(fd){
229 			close(pfd[0]);
230 			dup2(pfd[1], 1);
231 			close(pfd[1]);
232 		}
233 		if(e)
234 			exportenv(e, sh);
235 		n = shargv(shellcmd, 2, &argv);
236 		argv[n++] = "-c";
237 		argv[n++] = cmd;
238 		argv[n] = 0;
239 		execvp(argv[0], argv);
240 		mkperror(shell);
241 		_exit(1);
242 	}
243 	if(fd){
244 		close(pfd[1]);
245 		*fd = pfd[0];
246 	}
247 	return pid;
248 }
249 
250 void
251 Exit(void)
252 {
253 	while(wait(0) >= 0)
254 		;
255 	exits("error");
256 }
257 
258 static	struct
259 {
260 	int	sig;
261 	char	*msg;
262 }	sigmsgs[] =
263 {
264 	SIGALRM,	"alarm",
265 	SIGFPE,		"sys: fp: fptrap",
266 	SIGPIPE,	"sys: write on closed pipe",
267 	SIGILL,		"sys: trap: illegal instruction",
268 /*	SIGSEGV,	"sys: segmentation violation", */
269 	0,		0
270 };
271 
272 static void
273 notifyf(int sig)
274 {
275 	int i;
276 
277 	for(i = 0; sigmsgs[i].msg; i++)
278 		if(sigmsgs[i].sig == sig)
279 			killchildren(sigmsgs[i].msg);
280 
281 	/* should never happen */
282 	signal(sig, SIG_DFL);
283 	kill(getpid(), sig);
284 }
285 
286 void
287 catchnotes(void)
288 {
289 	int i;
290 
291 	for(i = 0; sigmsgs[i].msg; i++)
292 		signal(sigmsgs[i].sig, notifyf);
293 }
294 
295 char*
296 maketmp(int *pfd)
297 {
298 	static char temp[] = "/tmp/mkargXXXXXX";
299 	static char buf[100];
300 	int fd;
301 
302 	strcpy(buf, temp);
303 	fd = mkstemp(buf);
304 	if(fd < 0)
305 		return 0;
306 	*pfd = fd;
307 	return buf;
308 }
309 
310 int
311 chgtime(char *name)
312 {
313 	if(access(name, 0) >= 0)
314 		return utimes(name, 0);
315 	return close(creat(name, 0666));
316 }
317 
318 void
319 rcopy(char **to, Resub *match, int n)
320 {
321 	int c;
322 	char *p;
323 
324 	*to = match->s.sp;		/* stem0 matches complete target */
325 	for(to++, match++; --n > 0; to++, match++){
326 		if(match->s.sp && match->e.ep){
327 			p = match->e.ep;
328 			c = *p;
329 			*p = 0;
330 			*to = strdup(match->s.sp);
331 			*p = c;
332 		}
333 		else
334 			*to = 0;
335 	}
336 }
337 
338 unsigned long
339 mkmtime(char *name)
340 {
341 	struct stat st;
342 
343 	if(stat(name, &st) < 0)
344 		return 0;
345 
346 	return st.st_mtime;
347 }