PWCACHE(3)              NetBSD Library Functions Manual             PWCACHE(3)

NAME
     pwcache, user_from_uid, group_from_gid -- cache password and group
     entries

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <pwd.h>

     const char *
     user_from_uid(uid_t uid, int nouser);

     int
     uid_from_user(const char *name, uid_t *uid);

     int
     pwcache_userdb(int (*setpassent)(int), void (*endpwent)(void),
         struct passwd * (*getpwnam)(const char *),
         struct passwd * (*getpwuid)(uid_t));

     #include <grp.h>

     const char *
     group_from_gid(gid_t gid, int nogroup);

     int
     gid_from_group(const char *name, gid_t *gid);

     int
     pwcache_groupdb(int (*setgroupent)(int), void (*endgrent)(void),
         struct group * (*getgrnam)(const char *),
         struct group * (*getgrgid)(gid_t));

DESCRIPTION
     The user_from_uid() function returns the user name associated with the
     argument uid.  The user name is cached so that multiple calls with the
     same uid do not require additional calls to getpwuid(3).  If there is no
     user associated with the uid, a pointer is returned to a string represen-
     tation of the uid, unless the argument nouser is non-zero, in which case
     a NULL pointer is returned.

     The group_from_gid() function returns the group name associated with the
     argument gid.  The group name is cached so that multiple calls with the
     same gid do not require additional calls to getgrgid(3).  If there is no
     group associated with the gid, a pointer is returned to a string repre-
     sentation of the gid, unless the argument nogroup is non-zero, in which
     case a NULL pointer is returned.

     The uid_from_user() function returns the uid associated with the argument
     name.  The uid is cached so that multiple calls with the same name do not
     require additional calls to getpwnam(3).  If there is no uid associated
     with the name, the uid_from_user() function returns -1; otherwise it
     stores the uid at the location pointed to by uid and returns 0.

     The gid_from_group() function returns the gid associated with the argu-
     ment name.  The gid is cached so that multiple calls with the same name
     do not require additional calls to getgrnam(3).  If there is no gid asso-
     ciated with the name, the gid_from_group() function returns -1; otherwise
     it stores the gid at the location pointed to by gid and returns 0.

     The pwcache_userdb() function changes the user database access routines
     which user_from_uid() and uid_from_user() call to search for users.  The
     caches are flushed and the existing endpwent() method is called before
     switching to the new routines.  getpwnam and getpwuid must be provided,
     and setpassent and endpwent may be NULL pointers.

     The pwcache_groupdb() function changes the group database access routines
     which group_from_gid() and gid_from_group() call to search for groups.
     The caches are flushed and the existing endgrent() method is called
     before switching to the new routines.  getgrnam and getgrgid must be pro-
     vided, and setgroupent and endgrent may be NULL pointers.

SEE ALSO
     getgrgid(3), getgrnam(3), getpwnam(3), getpwuid(3)

HISTORY
     The user_from_uid() and group_from_gid() functions first appeared in
     4.4BSD.

     The uid_from_user() and gid_from_group() functions first appeared in
     NetBSD 1.4.

     The pwcache_userdb() and pwcache_groupdb() functions first appeared in
     NetBSD 1.6.

NetBSD 5.0_STABLE              January 24, 2002              NetBSD 5.0_STABLE
