#include "common.h"#include <auth.h>#include <ndb.h> /* *  return the date */char*thedate(void){	static char now[64]; 	strcpy(now, ctime(time(0)));	now[28] = 0;	return now;} /* *  return the user id of the current user */char *getlog(void){	return getuser();} /* *  return the lock name (we use one lock per directory) */static voidlockname(Mlock *l, char *path){	char *e, *q; 	seprint(l->name, e = l->name+sizeof l->name, "%s", path);	q = strrchr(l->name, '/');	if(q == nil)		q = l->name;	else		q++;	seprint(q, e, "%s", "L.mbox");} intsyscreatelocked(char *path, int mode, int perm){	return create(path, mode, DMEXCL|perm);} intsysopenlocked(char *path, int mode){/*	return open(path, OEXCL|mode);/**/	return open(path, mode);		/* until system call is fixed */} intsysunlockfile(int fd){	return close(fd);} /* *  try opening a lock file.  If it doesn't exist try creating it. */static intopenlockfile(Mlock *l){	int fd;	Dir *d, nd;	char *p; 	l->fd = open(l->name, OREAD);	if(l->fd >= 0)		return 0;	if(d = dirstat(l->name)){		free(d);		return 1;	/* try again later */	}	l->fd = create(l->name, OREAD, DMEXCL|0666);	if(l->fd >= 0){		nulldir(&nd);		nd.mode = DMEXCL|0666;		if(dirfwstat(l->fd, &nd) < 0){			/* if we can't chmod, don't bother */			/* live without the lock but log it */			close(l->fd);			l->fd = -1;			syslog(0, "mail", "lock error: %s: %r", l->name);			remove(l->name);		}		return 0;	}	/* couldn't create; let's see what we can whine about */	p = strrchr(l->name, '/');	if(p != 0){		*p = 0;		fd = access(l->name, 2);		*p = '/';	}else		fd = access(".", 2);	if(fd < 0)		/* live without the lock but log it */		syslog(0, "mail", "lock error: %s: %r", l->name);	close(fd);	return 0;} #define LSECS 5*60 /* *  Set a lock for a particular file.  The lock is a file in the same directory *  and has L. prepended to the name of the last element of the file name. */Mlock*syslock(char *path){	Mlock *l;	int tries; 	l = mallocz(sizeof(Mlock), 1);	if(l == 0)		return nil; 	lockname(l, path);	/*	 *  wait LSECS seconds for it to unlock	 */	for(tries = 0; tries < LSECS*2; tries++)		switch(openlockfile(l)){		case 0:			return l;		case 1:			sleep(500);			break;		}	free(l);	return nil;} /* *  like lock except don't wait */Mlock *trylock(char *path){	char buf[1];	int fd;	Mlock *l; 	l = mallocz(sizeof(Mlock), 1);	if(l == 0)		return 0; 	lockname(l, path);	if(openlockfile(l) != 0){		free(l);		return 0;	}		/* fork process to keep lock alive */	switch(l->pid = rfork(RFPROC)){	default:		break;	case 0:		fd = l->fd;		for(;;){			sleep(1000*60);			if(pread(fd, buf, 1, 0) < 0)				break;		}		_exits(nil);	}	return l;} voidsyslockrefresh(Mlock *l){	char buf[1]; 	pread(l->fd, buf, 1, 0);} voidsysunlock(Mlock *l){	if(l == 0)		return;	close(l->fd);	if(l->pid > 0)		postnote(PNPROC, l->pid, "time to die");	free(l);} /* *  Open a file.  The modes are: * *	l	- locked *	a	- set append permissions *	r	- readable *	w	- writable *	A	- append only (doesn't exist in Bio) */Biobuf*sysopen(char *path, char *mode, ulong perm){	int sysperm, sysmode, fd, docreate, append, truncate;	Dir *d, nd;	Biobuf *bp; 	/*	 *  decode the request	 */	sysperm = 0;	sysmode = -1;	docreate = 0;	append = 0;	truncate = 0; 	for(; *mode; mode++)		switch(*mode){		case 'A':			sysmode = OWRITE;			append = 1;			break;		case 'c':			docreate = 1;			break;		case 'l':			sysperm |= DMEXCL;			break;		case 'a':			sysperm |= DMAPPEND;			break;		case 'w':			if(sysmode == -1)				sysmode = OWRITE;			else				sysmode = ORDWR;			break;		case 'r':			if(sysmode == -1)				sysmode = OREAD;			else				sysmode = ORDWR;			break;		case 't':			truncate = 1;			break;		default:			break;		}	switch(sysmode){	case OREAD:	case OWRITE:	case ORDWR:		break;	default:		if(sysperm&DMAPPEND)			sysmode = OWRITE;		else			sysmode = OREAD;		break;	} 	/*	 *  create file if we need to	 */	if(truncate)		sysmode |= OTRUNC;	fd = open(path, sysmode);	if(fd < 0){		d = dirstat(path);		if(d == nil){			if(docreate == 0)				return 0; 			fd = create(path, sysmode, sysperm|perm);			if(fd < 0)				return 0;			nulldir(&nd);			nd.mode = sysperm|perm;			dirfwstat(fd, &nd);		} else {			free(d);			return 0;		}	} 	bp = (Biobuf*)malloc(sizeof(Biobuf));	if(bp == 0){		close(fd);		return 0;	}	memset(bp, 0, sizeof(Biobuf));	Binit(bp, fd, sysmode&~OTRUNC); 	if(append)		Bseek(bp, 0, 2);	return bp;} /* *  close the file, etc. */intsysclose(Biobuf *bp){	int rv; 	rv = Bterm(bp);	close(Bfildes(bp));	free(bp);	return rv;} /* *  make a directory */intsysmkdir(char *file, ulong perm){	int fd; 	if((fd = create(file, OREAD, DMDIR|perm)) < 0)		return -1;	close(fd);	return 0;} /* *  read in the system name */char *sysname_read(void){	static char name[128];	char *s, *c; 	c = s = getenv("site");	if(!c)		c = alt_sysname_read();	if(!c)		c = "kremvax";	strecpy(name, name+sizeof name, c);	free(s);	return name;} char *alt_sysname_read(void){	return sysname();} /* *  get all names */char**sysnames_read(void){	int n;	Ndbtuple *t, *nt;	static char **namev; 	if(namev)		return namev; 	free(csgetvalue(0, "sys", sysname(), "dom", &t)); 	n = 0;	for(nt = t; nt; nt = nt->entry)		if(strcmp(nt->attr, "dom") == 0)			n++; 	namev = (char**)malloc(sizeof(char *)*(n+3));	if(namev){		namev[0] = strdup(sysname_read());		namev[1] = strdup(alt_sysname_read());		n = 2;		for(nt = t; nt; nt = nt->entry)			if(strcmp(nt->attr, "dom") == 0)				namev[n++] = strdup(nt->val);		namev[n] = 0;	}	if(t)		ndbfree(t); 	return namev;} /* *  read in the domain name */char*domainname_read(void){	char **p; 	for(p = sysnames_read(); *p; p++)		if(strchr(*p, '.'))			return *p;	return 0;} /* *  rename a file, fails unless both are in the same directory */intsysrename(char *old, char *new){	Dir d;	char *obase;	char *nbase; 	obase = strrchr(old, '/');	nbase = strrchr(new, '/');	if(obase){		if(nbase == 0)			return -1;		if(strncmp(old, new, obase-old) != 0)			return -1;		nbase++;	} else {		if(nbase)			return -1;		nbase = new;	}	nulldir(&d);	d.name = nbase;	return dirwstat(old, &d);} intsysexist(char *file){	return access(file, AEXIST) == 0;} static char yankeepig[] = "die: yankee pig dog"; intsyskill(int pid){	return postnote(PNPROC, pid, yankeepig);} intsyskillpg(int pid){	return postnote(PNGROUP, pid, yankeepig);} intsysdetach(void){	if(rfork(RFENVG|RFNAMEG|RFNOTEG) < 0) {		werrstr("rfork failed");		return -1;	}	return 0;} /* *  catch a write on a closed pipe */static int *closedflag;static intcatchpipe(void *, char *msg){	static char *foo = "sys: write on closed pipe"; 	if(strncmp(msg, foo, strlen(foo)) == 0){		if(closedflag)			*closedflag = 1;		return 1;	}	return 0;}voidpipesig(int *flagp){	closedflag = flagp;	atnotify(catchpipe, 1);}voidpipesigoff(void){	atnotify(catchpipe, 0);} intislikeatty(int fd){	char buf[64];	int l; 	if(fd2path(fd, buf, sizeof buf) != 0)		return 0; 

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