/*
 * Look up user and/or group names.
 *
 * This file should be modified for non-unix systems to do something
 * reasonable.
 *
 * @(#)names.c 1.1 9/9/86 Public Domain - gnu
 * MS-DOS port 2/87 by E. Roskos.
 * Minix  port 3/88 by E. Roskos.
 */
#include <sys/types.h>
#ifndef MSDOS
#include <pwd.h>
#include <grp.h>
#endif
#include "tar.h"

static int      saveuid = -993;
static char     saveuname[TUNMLEN];
static int      my_uid = -993;

static int      savegid = -993;
static char     savegname[TGNMLEN];
static int      my_gid = -993;

#define myuid	( my_uid < 0? my_uid = getuid(): my_uid )
#define	mygid	( my_gid < 0? my_gid = getgid(): my_gid )


#ifndef NONAMES
/*
 * Look up a user or group name from a uid/gid, maintaining a cache.
 * FIXME, for now it's a one-entry cache.
 * FIXME2, the "-993" is to reduce the chance of a hit on the first lookup.
 *
 * This is ifdef'd because on Suns, it drags in about 38K of "yellow
 * pages" code, roughly doubling the program size.  Thanks guys.
 */
void
finduname(uname, uid)
char            uname[TUNMLEN];
int             uid;

{
	struct passwd  *pw;
	extern struct passwd *getpwuid();

	if (uid != saveuid)
	{
		saveuid = uid;
		saveuname[0] = '\0';
		pw = getpwuid(uid);
		if (pw)
			strncpy(saveuname, pw->pw_name, TUNMLEN);
	}
	strncpy(uname, saveuname, TUNMLEN);
}

int
finduid(uname)
char            uname[TUNMLEN];

{
	struct passwd  *pw;
	extern struct passwd *getpwnam();

	if (uname[0] != saveuname[0]/* Quick test w/o proc call */
		|| 0 != strncmp(uname, saveuname, TUNMLEN))
	{
		strncpy(saveuname, uname, TUNMLEN);
		pw = getpwnam(uname);
		if (pw)
		{
			saveuid = pw->pw_uid;
		}
		else
		{
			saveuid = myuid;
		}
	}
	return saveuid;
}


void
findgname(gname, gid)
char            gname[TGNMLEN];
int             gid;

{
	struct group   *gr;
	extern struct group *getgrgid();

	if (gid != savegid)
	{
		savegid = gid;
		savegname[0] = '\0';
		(void) setgrent();
		gr = getgrgid(gid);
		if (gr)
			strncpy(savegname, gr->gr_name, TGNMLEN);
	}
	(void) strncpy(gname, savegname, TGNMLEN);
}


int
findgid(gname)
char            gname[TUNMLEN];

{
	struct group   *gr;
	extern struct group *getgrnam();

	if (gname[0] != savegname[0]/* Quick test w/o proc call */
		|| 0 != strncmp(gname, savegname, TUNMLEN))
	{
		strncpy(savegname, gname, TUNMLEN);
		gr = getgrnam(gname);
		if (gr)
		{
			savegid = gr->gr_gid;
		}
		else
		{
			savegid = mygid;
		}
	}
	return savegid;
}

#endif