fossil: import from plan 9

R=rsc
https://codereview.appspot.com/7988047

1 files changed, 948 insertions, 0 deletions

diff --git a/src/cmd/fossil/9user.c b/src/cmd/fossil/9user.c
new file mode 100644
index 00000000..98203d0b
--- /dev/null
+++ b/src/cmd/fossil/9user.c
@@ -0,0 +1,948 @@
+#include "stdinc.h"
+
+#include "9.h"
+
+enum {
+	NUserHash	= 1009,
+};
+
+typedef struct Ubox Ubox;
+typedef struct User User;
+
+struct User {
+	char*	uid;
+	char*	uname;
+	char*	leader;
+	char**	group;
+	int	ngroup;
+
+	User*	next;			/* */
+	User*	ihash;			/* lookup by .uid */
+	User*	nhash;			/* lookup by .uname */
+};
+
+#pragma varargck type "U"   User*
+
+struct Ubox {
+	User*	head;
+	User*	tail;
+	int	nuser;
+	int	len;
+
+	User*	ihash[NUserHash];	/* lookup by .uid */
+	User*	nhash[NUserHash];	/* lookup by .uname */
+};
+
+static struct {
+	VtLock*	lock;
+
+	Ubox*	box;
+} ubox;
+
+static char usersDefault[] = {
+	"adm:adm:adm:sys\n"
+	"none:none::\n"
+	"noworld:noworld::\n"
+	"sys:sys::glenda\n"
+	"glenda:glenda:glenda:\n"
+};
+
+static char* usersMandatory[] = {
+	"adm",
+	"none",
+	"noworld",
+	"sys",
+	nil,
+};
+
+char* uidadm = "adm";
+char* unamenone = "none";
+char* uidnoworld = "noworld";
+
+static u32int
+userHash(char* s)
+{
+	uchar *p;
+	u32int hash;
+
+	hash = 0;
+	for(p = (uchar*)s; *p != '\0'; p++)
+		hash = hash*7 + *p;
+
+	return hash % NUserHash;
+}
+
+static User*
+_userByUid(Ubox* box, char* uid)
+{
+	User *u;
+
+	if(box != nil){
+		for(u = box->ihash[userHash(uid)]; u != nil; u = u->ihash){
+			if(strcmp(u->uid, uid) == 0)
+				return u;
+		}
+	}
+	vtSetError("uname: uid '%s' not found", uid);
+	return nil;
+}
+
+char*
+unameByUid(char* uid)
+{
+	User *u;
+	char *uname;
+
+	vtRLock(ubox.lock);
+	if((u = _userByUid(ubox.box, uid)) == nil){
+		vtRUnlock(ubox.lock);
+		return nil;
+	}
+	uname = vtStrDup(u->uname);
+	vtRUnlock(ubox.lock);
+
+	return uname;
+}
+
+static User*
+_userByUname(Ubox* box, char* uname)
+{
+	User *u;
+
+	if(box != nil){
+		for(u = box->nhash[userHash(uname)]; u != nil; u = u->nhash){
+			if(strcmp(u->uname, uname) == 0)
+				return u;
+		}
+	}
+	vtSetError("uname: uname '%s' not found", uname);
+	return nil;
+}
+
+char*
+uidByUname(char* uname)
+{
+	User *u;
+	char *uid;
+
+	vtRLock(ubox.lock);
+	if((u = _userByUname(ubox.box, uname)) == nil){
+		vtRUnlock(ubox.lock);
+		return nil;
+	}
+	uid = vtStrDup(u->uid);
+	vtRUnlock(ubox.lock);
+
+	return uid;
+}
+
+static int
+_groupMember(Ubox* box, char* group, char* member, int whenNoGroup)
+{
+	int i;
+	User *g, *m;
+
+	/*
+	 * Is 'member' a member of 'group'?
+	 * Note that 'group' is a 'uid' and not a 'uname'.
+	 * A 'member' is automatically in their own group.
+	 */
+	if((g = _userByUid(box, group)) == nil)
+		return whenNoGroup;
+	if((m = _userByUname(box, member)) == nil)
+		return 0;
+	if(m == g)
+		return 1;
+	for(i = 0; i < g->ngroup; i++){
+		if(strcmp(g->group[i], member) == 0)
+			return 1;
+	}
+	return 0;
+}
+
+int
+groupWriteMember(char* uname)
+{
+	int ret;
+
+	/*
+	 * If there is a ``write'' group, then only its members can write
+	 * to the file system, no matter what the permission bits say.
+	 *
+	 * To users not in the ``write'' group, the file system appears
+	 * read only.  This is used to serve sources.cs.bell-labs.com
+	 * to the world.
+	 *
+	 * Note that if there is no ``write'' group, then this routine
+	 * makes it look like everyone is a member -- the opposite
+	 * of what groupMember does.
+	 *
+	 * We use this for sources.cs.bell-labs.com.
+	 * If this slows things down too much on systems that don't
+	 * use this functionality, we could cache the write group lookup.
+	 */
+
+	vtRLock(ubox.lock);
+	ret = _groupMember(ubox.box, "write", uname, 1);
+	vtRUnlock(ubox.lock);
+	return ret;
+}
+
+static int
+_groupRemMember(Ubox* box, User* g, char* member)
+{
+	int i;
+
+	if(_userByUname(box, member) == nil)
+		return 0;
+
+	for(i = 0; i < g->ngroup; i++){
+		if(strcmp(g->group[i], member) == 0)
+			break;
+	}
+	if(i >= g->ngroup){
+		if(strcmp(g->uname, member) == 0)
+			vtSetError("uname: '%s' always in own group", member);
+		else
+			vtSetError("uname: '%s' not in group '%s'",
+				member, g->uname);
+		return 0;
+	}
+
+	vtMemFree(g->group[i]);
+
+	box->len -= strlen(member);
+	if(g->ngroup > 1)
+		box->len--;
+	g->ngroup--;
+	switch(g->ngroup){
+	case 0:
+		vtMemFree(g->group);
+		g->group = nil;
+		break;
+	default:
+		for(; i < g->ngroup; i++)
+			g->group[i] = g->group[i+1];
+		g->group[i] = nil;		/* prevent accidents */
+		g->group = vtMemRealloc(g->group, g->ngroup * sizeof(char*));
+		break;
+	}
+
+	return 1;
+}
+
+static int
+_groupAddMember(Ubox* box, User* g, char* member)
+{
+	User *u;
+
+	if((u = _userByUname(box, member)) == nil)
+		return 0;
+	if(_groupMember(box, g->uid, u->uname, 0)){
+		if(strcmp(g->uname, member) == 0)
+			vtSetError("uname: '%s' always in own group", member);
+		else
+			vtSetError("uname: '%s' already in group '%s'",
+				member, g->uname);
+		return 0;
+	}
+
+	g->group = vtMemRealloc(g->group, (g->ngroup+1)*sizeof(char*));
+	g->group[g->ngroup] = vtStrDup(member);
+	box->len += strlen(member);
+	g->ngroup++;
+	if(g->ngroup > 1)
+		box->len++;
+
+	return 1;
+}
+
+int
+groupMember(char* group, char* member)
+{
+	int r;
+
+	if(group == nil)
+		return 0;
+
+	vtRLock(ubox.lock);
+	r = _groupMember(ubox.box, group, member, 0);
+	vtRUnlock(ubox.lock);
+
+	return r;
+}
+
+int
+groupLeader(char* group, char* member)
+{
+	int r;
+	User *g;
+
+	/*
+	 * Is 'member' the leader of 'group'?
+	 * Note that 'group' is a 'uid' and not a 'uname'.
+	 * Uname 'none' cannot be a group leader.
+	 */
+	if(strcmp(member, unamenone) == 0 || group == nil)
+		return 0;
+
+	vtRLock(ubox.lock);
+	if((g = _userByUid(ubox.box, group)) == nil){
+		vtRUnlock(ubox.lock);
+		return 0;
+	}
+	if(g->leader != nil){
+		if(strcmp(g->leader, member) == 0){
+			vtRUnlock(ubox.lock);
+			return 1;
+		}
+		r = 0;
+	}
+	else
+		r = _groupMember(ubox.box, group, member, 0);
+	vtRUnlock(ubox.lock);
+
+	return r;
+}
+
+static void
+userFree(User* u)
+{
+	int i;
+
+	vtMemFree(u->uid);
+	vtMemFree(u->uname);
+	if(u->leader != nil)
+		vtMemFree(u->leader);
+	if(u->ngroup){
+		for(i = 0; i < u->ngroup; i++)
+			vtMemFree(u->group[i]);
+		vtMemFree(u->group);
+	}
+	vtMemFree(u);
+}
+
+static User*
+userAlloc(char* uid, char* uname)
+{
+	User *u;
+
+	u = vtMemAllocZ(sizeof(User));
+	u->uid = vtStrDup(uid);
+	u->uname = vtStrDup(uname);
+
+	return u;
+}
+
+int
+validUserName(char* name)
+{
+	Rune *r;
+	static Rune invalid[] = L"#:,()";
+
+	for(r = invalid; *r != '\0'; r++){
+		if(utfrune(name, *r))
+			return 0;
+	}
+	return 1;
+}
+
+static int
+userFmt(Fmt* fmt)
+{
+	User *u;
+	int i, r;
+
+	u = va_arg(fmt->args, User*);
+
+	r = fmtprint(fmt, "%s:%s:", u->uid, u->uname);
+	if(u->leader != nil)
+		r += fmtprint(fmt, u->leader);
+	r += fmtprint(fmt, ":");
+	if(u->ngroup){
+		r += fmtprint(fmt, u->group[0]);
+		for(i = 1; i < u->ngroup; i++)
+			r += fmtprint(fmt, ",%s", u->group[i]);
+	}
+
+	return r;
+}
+
+static int
+usersFileWrite(Ubox* box)
+{
+	Fs *fs;
+	User *u;
+	int i, r;
+	Fsys *fsys;
+	char *p, *q, *s;
+	File *dir, *file;
+
+	if((fsys = fsysGet("main")) == nil)
+		return 0;
+	fsysFsRlock(fsys);
+	fs = fsysGetFs(fsys);
+
+	/*
+	 * BUG:
+	 * 	the owner/group/permissions need to be thought out.
+	 */
+	r = 0;
+	if((dir = fileOpen(fs, "/active")) == nil)
+		goto tidy0;
+	if((file = fileWalk(dir, uidadm)) == nil)
+		file = fileCreate(dir, uidadm, ModeDir|0775, uidadm);
+	fileDecRef(dir);
+	if(file == nil)
+		goto tidy;
+	dir = file;
+	if((file = fileWalk(dir, "users")) == nil)
+		file = fileCreate(dir, "users", 0664, uidadm);
+	fileDecRef(dir);
+	if(file == nil)
+		goto tidy;
+	if(!fileTruncate(file, uidadm))
+		goto tidy;
+
+	p = s = vtMemAlloc(box->len+1);
+	q = p + box->len+1;
+	for(u = box->head; u != nil; u = u->next){
+		p += snprint(p, q-p, "%s:%s:", u->uid, u->uname);
+		if(u->leader != nil)
+			p+= snprint(p, q-p, u->leader);
+		p += snprint(p, q-p, ":");
+		if(u->ngroup){
+			p += snprint(p, q-p, u->group[0]);
+			for(i = 1; i < u->ngroup; i++)
+				p += snprint(p, q-p, ",%s", u->group[i]);
+		}
+		p += snprint(p, q-p, "\n");
+	}
+	r = fileWrite(file, s, box->len, 0, uidadm);
+	vtMemFree(s);
+
+tidy:
+	if(file != nil)
+		fileDecRef(file);
+tidy0:
+	fsysFsRUnlock(fsys);
+	fsysPut(fsys);
+
+	return r;
+}
+
+static void
+uboxRemUser(Ubox* box, User *u)
+{
+	User **h, *up;
+
+	h = &box->ihash[userHash(u->uid)];
+	for(up = *h; up != nil && up != u; up = up->ihash)
+		h = &up->ihash;
+	assert(up == u);
+	*h = up->ihash;
+	box->len -= strlen(u->uid);
+
+	h = &box->nhash[userHash(u->uname)];
+	for(up = *h; up != nil && up != u; up = up->nhash)
+		h = &up->nhash;
+	assert(up == u);
+	*h = up->nhash;
+	box->len -= strlen(u->uname);
+
+	h = &box->head;
+	for(up = *h; up != nil && strcmp(up->uid, u->uid) != 0; up = up->next)
+		h = &up->next;
+	assert(up == u);
+	*h = u->next;
+	u->next = nil;
+
+	box->len -= 4;
+	box->nuser--;
+}
+
+static void
+uboxAddUser(Ubox* box, User* u)
+{
+	User **h, *up;
+
+	h = &box->ihash[userHash(u->uid)];
+	u->ihash = *h;
+	*h = u;
+	box->len += strlen(u->uid);
+
+	h = &box->nhash[userHash(u->uname)];
+	u->nhash = *h;
+	*h = u;
+	box->len += strlen(u->uname);
+
+	h = &box->head;
+	for(up = *h; up != nil && strcmp(up->uid, u->uid) < 0; up = up->next)
+		h = &up->next;
+	u->next = *h;
+	*h = u;
+
+	box->len += 4;
+	box->nuser++;
+}
+
+static void
+uboxDump(Ubox* box)
+{
+	User* u;
+
+	consPrint("nuser %d len = %d\n", box->nuser, box->len);
+
+	for(u = box->head; u != nil; u = u->next)
+		consPrint("%U\n", u);
+}
+
+static void
+uboxFree(Ubox* box)
+{
+	User *next, *u;
+
+	for(u = box->head; u != nil; u = next){
+		next = u->next;
+		userFree(u);
+	}
+	vtMemFree(box);
+}
+
+static int
+uboxInit(char* users, int len)
+{
+	User *g, *u;
+	Ubox *box, *obox;
+	int blank, comment, i, nline, nuser;
+	char *buf, *f[5], **line, *p, *q, *s;
+
+	/*
+	 * Strip out whitespace and comments.
+	 * Note that comments are pointless, they disappear
+	 * when the server writes the database back out.
+	 */
+	blank = 1;
+	comment = nline = 0;
+
+	s = p = buf = vtMemAlloc(len+1);
+	for(q = users; *q != '\0'; q++){
+		if(*q == '\r' || *q == '\t' || *q == ' ')
+			continue;
+		if(*q == '\n'){
+			if(!blank){
+				if(p != s){
+					*p++ = '\n';
+					nline++;
+					s = p;
+				}
+				blank = 1;
+			}
+			comment = 0;
+			continue;
+		}
+		if(*q == '#')
+			comment = 1;
+		blank = 0;
+		if(!comment)
+			*p++ = *q;
+	}
+	*p = '\0';
+
+	line = vtMemAllocZ((nline+2)*sizeof(char*));
+	if((i = gettokens(buf, line, nline+2, "\n")) != nline){
+		fprint(2, "nline %d (%d) botch\n", nline, i);
+		vtMemFree(line);
+		vtMemFree(buf);
+		return 0;
+	}
+
+	/*
+	 * Everything is updated in a local Ubox until verified.
+	 */
+	box = vtMemAllocZ(sizeof(Ubox));
+
+	/*
+	 * First pass - check format, check for duplicates
+	 * and enter in hash buckets.
+	 */
+	nuser = 0;
+	for(i = 0; i < nline; i++){
+		s = vtStrDup(line[i]);
+		if(getfields(s, f, nelem(f), 0, ":") != 4){
+			fprint(2, "bad line '%s'\n", line[i]);
+			vtMemFree(s);
+			continue;
+		}
+		if(*f[0] == '\0' || *f[1] == '\0'){
+			fprint(2, "bad line '%s'\n", line[i]);
+			vtMemFree(s);
+			continue;
+		}
+		if(!validUserName(f[0])){
+			fprint(2, "invalid uid '%s'\n", f[0]);
+			vtMemFree(s);
+			continue;
+		}
+		if(_userByUid(box, f[0]) != nil){
+			fprint(2, "duplicate uid '%s'\n", f[0]);
+			vtMemFree(s);
+			continue;
+		}
+		if(!validUserName(f[1])){
+			fprint(2, "invalid uname '%s'\n", f[0]);
+			vtMemFree(s);
+			continue;
+		}
+		if(_userByUname(box, f[1]) != nil){
+			fprint(2, "duplicate uname '%s'\n", f[1]);
+			vtMemFree(s);
+			continue;
+		}
+
+		u = userAlloc(f[0], f[1]);
+		uboxAddUser(box, u);
+		line[nuser] = line[i];
+		nuser++;
+
+		vtMemFree(s);
+	}
+	assert(box->nuser == nuser);
+
+	/*
+	 * Second pass - fill in leader and group information.
+	 */
+	for(i = 0; i < nuser; i++){
+		s = vtStrDup(line[i]);
+		getfields(s, f, nelem(f), 0, ":");
+
+		assert(g = _userByUname(box, f[1]));
+		if(*f[2] != '\0'){
+			if((u = _userByUname(box, f[2])) == nil)
+				g->leader = vtStrDup(g->uname);
+			else
+				g->leader = vtStrDup(u->uname);
+			box->len += strlen(g->leader);
+		}
+		for(p = f[3]; p != nil; p = q){
+			if((q = utfrune(p, L',')) != nil)
+				*q++ = '\0';
+			if(!_groupAddMember(box, g, p)){
+				// print/log error here
+			}
+		}
+
+		vtMemFree(s);
+	}
+
+	vtMemFree(line);
+	vtMemFree(buf);
+
+	for(i = 0; usersMandatory[i] != nil; i++){
+		if((u = _userByUid(box, usersMandatory[i])) == nil){
+			vtSetError("user '%s' is mandatory", usersMandatory[i]);
+			uboxFree(box);
+			return 0;
+		}
+		if(strcmp(u->uid, u->uname) != 0){
+			vtSetError("uid/uname for user '%s' must match",
+				usersMandatory[i]);
+			uboxFree(box);
+			return 0;
+		}
+	}
+
+	vtLock(ubox.lock);
+	obox = ubox.box;
+	ubox.box = box;
+	vtUnlock(ubox.lock);
+
+	if(obox != nil)
+		uboxFree(obox);
+
+	return 1;
+}
+
+int
+usersFileRead(char* path)
+{
+	char *p;
+	File *file;
+	Fsys *fsys;
+	int len, r;
+	uvlong size;
+
+	if((fsys = fsysGet("main")) == nil)
+		return 0;
+	fsysFsRlock(fsys);
+
+	if(path == nil)
+		path = "/active/adm/users";
+
+	r = 0;
+	if((file = fileOpen(fsysGetFs(fsys), path)) != nil){
+		if(fileGetSize(file, &size)){
+			len = size;
+			p = vtMemAlloc(size+1);
+			if(fileRead(file, p, len, 0) == len){
+				p[len] = '\0';
+				r = uboxInit(p, len);
+			}
+		}
+		fileDecRef(file);
+	}
+
+	fsysFsRUnlock(fsys);
+	fsysPut(fsys);
+
+	return r;
+}
+
+static int
+cmdUname(int argc, char* argv[])
+{
+	User *u, *up;
+	int d, dflag, i, r;
+	char *p, *uid, *uname;
+	char *createfmt = "fsys main create /active/usr/%s %s %s d775";
+	char *usage = "usage: uname [-d] uname [uid|:uid|%%newname|=leader|+member|-member]";
+
+	dflag = 0;
+
+	ARGBEGIN{
+	default:
+		return cliError(usage);
+	case 'd':
+		dflag = 1;
+		break;
+	}ARGEND
+
+	if(argc < 1){
+		if(!dflag)
+			return cliError(usage);
+		vtRLock(ubox.lock);
+		uboxDump(ubox.box);
+		vtRUnlock(ubox.lock);
+		return 1;
+	}
+
+	uname = argv[0];
+	argc--; argv++;
+
+	if(argc == 0){
+		vtRLock(ubox.lock);
+		if((u = _userByUname(ubox.box, uname)) == nil){
+			vtRUnlock(ubox.lock);
+			return 0;
+		}
+		consPrint("\t%U\n", u);
+		vtRUnlock(ubox.lock);
+		return 1;
+	}
+
+	vtLock(ubox.lock);
+	u = _userByUname(ubox.box, uname);
+	while(argc--){
+		if(argv[0][0] == '%'){
+			if(u == nil){
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+			p = &argv[0][1];
+			if((up = _userByUname(ubox.box, p)) != nil){
+				vtSetError("uname: uname '%s' already exists",
+					up->uname);
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+			for(i = 0; usersMandatory[i] != nil; i++){
+				if(strcmp(usersMandatory[i], uname) != 0)
+					continue;
+				vtSetError("uname: uname '%s' is mandatory",
+					uname);
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+
+			d = strlen(p) - strlen(u->uname);
+			for(up = ubox.box->head; up != nil; up = up->next){
+				if(up->leader != nil){
+					if(strcmp(up->leader, u->uname) == 0){
+						vtMemFree(up->leader);
+						up->leader = vtStrDup(p);
+						ubox.box->len += d;
+					}
+				}
+				for(i = 0; i < up->ngroup; i++){
+					if(strcmp(up->group[i], u->uname) != 0)
+						continue;
+					vtMemFree(up->group[i]);
+					up->group[i] = vtStrDup(p);
+					ubox.box->len += d;
+					break;
+				}
+			}
+
+			uboxRemUser(ubox.box, u);
+			vtMemFree(u->uname);
+			u->uname = vtStrDup(p);
+			uboxAddUser(ubox.box, u);
+		}
+		else if(argv[0][0] == '='){
+			if(u == nil){
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+			if((up = _userByUname(ubox.box, &argv[0][1])) == nil){
+				if(argv[0][1] != '\0'){
+					vtUnlock(ubox.lock);
+					return 0;
+				}
+			}
+			if(u->leader != nil){
+				ubox.box->len -= strlen(u->leader);
+				vtMemFree(u->leader);
+				u->leader = nil;
+			}
+			if(up != nil){
+				u->leader = vtStrDup(up->uname);
+				ubox.box->len += strlen(u->leader);
+			}
+		}
+		else if(argv[0][0] == '+'){
+			if(u == nil){
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+			if((up = _userByUname(ubox.box, &argv[0][1])) == nil){
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+			if(!_groupAddMember(ubox.box, u, up->uname)){
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+		}
+		else if(argv[0][0] == '-'){
+			if(u == nil){
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+			if((up = _userByUname(ubox.box, &argv[0][1])) == nil){
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+			if(!_groupRemMember(ubox.box, u, up->uname)){
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+		}
+		else{
+			if(u != nil){
+				vtSetError("uname: uname '%s' already exists",
+					u->uname);
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+
+			uid = argv[0];
+			if(*uid == ':')
+				uid++;
+			if((u = _userByUid(ubox.box, uid)) != nil){
+				vtSetError("uname: uid '%s' already exists",
+					u->uid);
+				vtUnlock(ubox.lock);
+				return 0;
+			}
+
+			u = userAlloc(uid, uname);
+			uboxAddUser(ubox.box, u);
+			if(argv[0][0] != ':'){
+				// should have an option for the mode and gid
+				p = smprint(createfmt, uname, uname, uname);
+				r = cliExec(p);
+				vtMemFree(p);
+				if(r == 0){
+					vtUnlock(ubox.lock);
+					return 0;
+				}
+			}
+		}
+		argv++;
+	}
+
+	if(usersFileWrite(ubox.box) == 0){
+		vtUnlock(ubox.lock);
+		return 0;
+	}
+	if(dflag)
+		uboxDump(ubox.box);
+	vtUnlock(ubox.lock);
+
+	return 1;
+}
+
+static int
+cmdUsers(int argc, char* argv[])
+{
+	Ubox *box;
+	int dflag, r, wflag;
+	char *file;
+	char *usage = "usage: users [-d | -r file] [-w]";
+
+	dflag = wflag = 0;
+	file = nil;
+
+	ARGBEGIN{
+	default:
+		return cliError(usage);
+	case 'd':
+		dflag = 1;
+		break;
+	case 'r':
+		file = ARGF();
+		if(file == nil)
+			return cliError(usage);
+		break;
+	case 'w':
+		wflag = 1;
+		break;
+	}ARGEND
+
+	if(argc)
+		return cliError(usage);
+
+	if(dflag && file)
+		return cliError("cannot use -d and -r together");
+
+	if(dflag)
+		uboxInit(usersDefault, sizeof(usersDefault));
+	else if(file){
+		if(usersFileRead(file) == 0)
+			return 0;
+	}
+
+	vtRLock(ubox.lock);
+	box = ubox.box;
+	consPrint("\tnuser %d len %d\n", box->nuser, box->len);
+
+	r = 1;
+	if(wflag)
+		r = usersFileWrite(box);
+	vtRUnlock(ubox.lock);
+	return r;
+}
+
+int
+usersInit(void)
+{
+	fmtinstall('U', userFmt);
+
+	ubox.lock = vtLockAlloc();
+	uboxInit(usersDefault, sizeof(usersDefault));
+
+	cliAddCmd("users", cmdUsers);
+	cliAddCmd("uname", cmdUname);
+
+	return 1;
+}