uname_gname.c

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#include "config.h"
#include "uname_gname.h"

#include <string.h>
#include <stdlib.h>
#include <grp.h>

#include "len.h"

static char *cached_uname;
static char *cached_gname;

static uid_t cached_uid;        /* valid only if cached_uname is not NULL */
static gid_t cached_gid;        /* valid only if cached_gname is not NULL */

char *get_uname(uid_t uid)
{
        char *ret = NULL;
        if(cached_uname == NULL || uid != cached_uid)
        {
                struct passwd *passwd = getpwuid(uid);
                if(passwd)
                {
                        cached_uid = uid;
                        free(cached_uname);
                        cached_uname = malloc(str_len(passwd->pw_name) + 1);
                        strcpy(cached_uname, passwd->pw_name);
                }
                else
                        return NULL;
        }
        ret = malloc(str_len(cached_uname) + 1);
        strcpy(ret, cached_uname);
        return ret;
}

char *get_gname(gid_t gid)
{
        char *ret = NULL;
        if(cached_gname == NULL || gid != cached_gid)
        {
                struct group *group = getgrgid(gid);
                if(group)
                {
                        cached_gid = gid;
                        free(cached_gname);
                        cached_gname = malloc(str_len(group->gr_name) + 1);
                        strcpy(cached_gname, group->gr_name);
                }
                else
                        return NULL;
        }
        ret = malloc(str_len(cached_gname) + 1);
        strcpy(ret, cached_gname);
        return ret;
}