9base

unix.c (5290B)

---

 #define NOPLAN9DEFINES
 #include	"mk.h"
 #include	<sys/wait.h>
 #include	<signal.h>
 #include	<sys/stat.h>
 #include	<sys/time.h>
 
 char	*shell = "/bin/sh";
 char	*shellname = "sh";
 
 extern char **environ;
 
 static void
 mkperror(char *s)
 {
 	fprint(2, "%s: %r\n", s);
 }
 
 void
 readenv(void)
 {
 	char **p, *s;
 	Word *w;
 
 	for(p = environ; *p; p++){
 /* rsc 5/5/2004 -- This misparses fn#cd={whatever} 
 		s = shname(*p);
 		if(*s == '=') {
 			*s = 0;
 			w = newword(s+1);
 		} else
 			w = newword("");
 */
 		s = strchr(*p, '=');
 		if(s){
 			*s = 0;
 			w = newword(s+1);
 		} else
 			w = newword("");
 		if (symlook(*p, S_INTERNAL, 0))
 			continue;
 		s = strdup(*p);
 		setvar(s, (void *)w);
 		symlook(s, S_EXPORTED, (void*)"")->u.ptr = "";
 	}
 }
 
 /*
  *	done on child side of fork, so parent's env is not affected
  *	and we don't care about freeing memory because we're going
  *	to exec immediately after this.
  */
 void
 exportenv(Envy *e, Shell *sh)
 {
 	int i;
 	char **p;
 	static char buf[16384];
 
 	p = 0;
 	for(i = 0; e->name; e++, i++) {
 		p = (char**) Realloc(p, (i+2)*sizeof(char*));
 		if(e->values)
 			snprint(buf, sizeof buf, "%s=%s", e->name,  wtos(e->values, sh->iws));
 		else
 			snprint(buf, sizeof buf, "%s=", e->name);
 		p[i] = strdup(buf);
 	}
 	p[i] = 0;
 	environ = p;
 }
 
 int
 waitfor(char *msg)
 {
 	int status;
 	int pid;
 
 	*msg = 0;
 	pid = wait(&status);
 	if(pid > 0) {
 		if(status&0x7f) {
 			if(status&0x80)
 				snprint(msg, ERRMAX, "signal %d, core dumped", status&0x7f);
 			else
 				snprint(msg, ERRMAX, "signal %d", status&0x7f);
 		} else if(status&0xff00)
 			snprint(msg, ERRMAX, "exit(%d)", (status>>8)&0xff);
 	}
 	return pid;
 }
 
 void
 expunge(int pid, char *msg)
 {
 	if(strcmp(msg, "interrupt"))
 		kill(pid, SIGINT);
 	else
 		kill(pid, SIGHUP);
 }
 
 int mypid;
 
 int
 shargv(Word *cmd, int extra, char ***pargv)
 {
 	char **argv;
 	int i, n;
 	Word *w;
 
 	n = 0;
 	for(w=cmd; w; w=w->next)
 		n++;
 	
 	argv = Malloc((n+extra+1)*sizeof(argv[0]));
 	i = 0;
 	for(w=cmd; w; w=w->next)
 		argv[i++] = w->s;
 	argv[n] = 0;
 	*pargv = argv;
 	return n;
 }	
 
 int
 execsh(char *args, char *cmd, Bufblock *buf, Envy *e, Shell *sh, Word *shellcmd)
 {
 	char *p, **argv;
 	int tot, n, pid, in[2], out[2];
 
 	if(buf && pipe(out) < 0){
 		mkperror("pipe");
 		Exit();
 	}
 	pid = fork();
 	mypid = getpid();
 	if(pid < 0){
 		mkperror("mk fork");
 		Exit();
 	}
 	if(pid == 0){
 		if(buf)
 			close(out[0]);
 		if(pipe(in) < 0){
 			mkperror("pipe");
 			Exit();
 		}
 		pid = fork();
 		if(pid < 0){
 			mkperror("mk fork");
 			Exit();
 		}
 		if(pid != 0){
 			dup2(in[0], 0);
 			if(buf){
 				dup2(out[1], 1);
 				close(out[1]);
 			}
 			close(in[0]);
 			close(in[1]);
 			if (e)
 				exportenv(e, sh);
 			n = shargv(shellcmd, 1, &argv);
 			argv[n++] = args;
 			argv[n] = 0;
 			execvp(argv[0], argv);
 			mkperror(shell);
 			_exit(1);
 		}
 		close(out[1]);
 		close(in[0]);
 		if(DEBUG(D_EXEC))
 			fprint(1, "starting: %s\n", cmd);
 		p = cmd+strlen(cmd);
 		while(cmd < p){
 			n = write(in[1], cmd, p-cmd);
 			if(n < 0)
 				break;
 			cmd += n;
 		}
 		close(in[1]);
 		_exit(0);
 	}
 	if(buf){
 		close(out[1]);
 		tot = 0;
 		for(;;){
 			if (buf->current >= buf->end)
 				growbuf(buf);
 			n = read(out[0], buf->current, buf->end-buf->current);
 			if(n <= 0)
 				break;
 			buf->current += n;
 			tot += n;
 		}
 		if (tot && buf->current[-1] == '\n')
 			buf->current--;
 		close(out[0]);
 	}
 	return pid;
 }
 
 int
 pipecmd(char *cmd, Envy *e, int *fd, Shell *sh, Word *shellcmd)
 {
 	int pid, pfd[2];
 	int n;
 	char **argv;
 
 	if(DEBUG(D_EXEC))
 		fprint(1, "pipecmd='%s'\n", cmd);/**/
 
 	if(fd && pipe(pfd) < 0){
 		mkperror("pipe");
 		Exit();
 	}
 	pid = fork();
 	if(pid < 0){
 		mkperror("mk fork");
 		Exit();
 	}
 	if(pid == 0){
 		if(fd){
 			close(pfd[0]);
 			dup2(pfd[1], 1);
 			close(pfd[1]);
 		}
 		if(e)
 			exportenv(e, sh);
 		n = shargv(shellcmd, 2, &argv);
 		argv[n++] = "-c";
 		argv[n++] = cmd;
 		argv[n] = 0;
 		execvp(argv[0], argv);
 		mkperror(shell);
 		_exit(1);
 	}
 	if(fd){
 		close(pfd[1]);
 		*fd = pfd[0];
 	}
 	return pid;
 }
 
 void
 Exit(void)
 {
 	while(wait(0) >= 0)
 		;
 	exits("error");
 }
 
 static	struct
 {
 	int	sig;
 	char	*msg;
 }	sigmsgs[] =
 {
 	SIGALRM,	"alarm",
 	SIGFPE,		"sys: fp: fptrap",
 	SIGPIPE,	"sys: write on closed pipe",
 	SIGILL,		"sys: trap: illegal instruction",
 /*	SIGSEGV,	"sys: segmentation violation", */
 	0,		0
 };
 
 static void
 notifyf(int sig)
 {
 	int i;
 
 	for(i = 0; sigmsgs[i].msg; i++)
 		if(sigmsgs[i].sig == sig)
 			killchildren(sigmsgs[i].msg);
 
 	/* should never happen */
 	signal(sig, SIG_DFL);
 	kill(getpid(), sig);
 }
 
 void
 catchnotes(void)
 {
 	int i;
 
 	for(i = 0; sigmsgs[i].msg; i++)
 		signal(sigmsgs[i].sig, notifyf);
 }
 
 char*
 maketmp(int *pfd)
 {
 	static char temp[] = "/tmp/mkargXXXXXX";
 	static char buf[100];
 	int fd;
 
 	strcpy(buf, temp);
 	fd = mkstemp(buf);
 	if(fd < 0)
 		return 0;
 	*pfd = fd;
 	return buf;
 }
 
 int
 chgtime(char *name)
 {
 	if(access(name, 0) >= 0)
 		return utimes(name, 0);
 	return close(creat(name, 0666));
 }
 
 void
 rcopy(char **to, Resub *match, int n)
 {
 	int c;
 	char *p;
 
 	*to = match->s.sp;		/* stem0 matches complete target */
 	for(to++, match++; --n > 0; to++, match++){
 		if(match->s.sp && match->e.ep){
 			p = match->e.ep;
 			c = *p;
 			*p = 0;
 			*to = strdup(match->s.sp);
 			*p = c;
 		}
 		else
 			*to = 0;
 	}
 }
 
 unsigned long
 mkmtime(char *name)
 {
 	struct stat st;
 
 	if(stat(name, &st) < 0)
 		return 0;
 
 	return st.st_mtime;
 }