// Copyright (C) 1992-1998 by Michael K. Johnson, johnsonm@redhat.com// Note: most likely none of his code remains//// Copyright 2002, Albert Cahalan//// This file is placed under the conditions of the GNU Library// General Public License, version 2, or any later version.// See file COPYING for information on distribution conditions.#include <stdio.h>#include <string.h>#include <sys/types.h>#include <stdlib.h>#include <pwd.h>#include "alloc.h"#include "pwcache.h"#include <grp.h>// might as well fill cache lines... else we waste memory anyway#define	HASHSIZE	64		/* power of 2 */#define	HASH(x)		((x) & (HASHSIZE - 1))static struct pwbuf {    struct pwbuf *next;    uid_t uid;    char name[P_G_SZ];} *pwhash[HASHSIZE];char *user_from_uid(uid_t uid) {    struct pwbuf **p;    struct passwd *pw;    p = &pwhash[HASH(uid)];    while (*p) {	if ((*p)->uid == uid)	    return((*p)->name);	p = &(*p)->next;    }    *p = (struct pwbuf *) xmalloc(sizeof(struct pwbuf));    (*p)->uid = uid;    pw = getpwuid(uid);    if(!pw || strlen(pw->pw_name) >= P_G_SZ)	sprintf((*p)->name, "%u", uid);    else        strcpy((*p)->name, pw->pw_name);    (*p)->next = NULL;    return((*p)->name);}static struct grpbuf {    struct grpbuf *next;    gid_t gid;    char name[P_G_SZ];} *grphash[HASHSIZE];char *group_from_gid(gid_t gid) {    struct grpbuf **g;    struct group *gr;    g = &grphash[HASH(gid)];    while (*g) {        if ((*g)->gid == gid)            return((*g)->name);        g = &(*g)->next;    }    *g = (struct grpbuf *) malloc(sizeof(struct grpbuf));    (*g)->gid = gid;    gr = getgrgid(gid);    if (!gr || strlen(gr->gr_name) >= P_G_SZ)        sprintf((*g)->name, "%u", gid);    else        strcpy((*g)->name, gr->gr_name);    (*g)->next = NULL;    return((*g)->name);}