plucky (3) pwcache.3bsd.gz

NAME

     user_from_uid, uid_from_user, group_from_gid, gid_from_group — cache password and group entries

LIBRARY

     Utility functions from BSD systems (libbsd, -lbsd)

SYNOPSIS

     #include <pwd.h>
     (See libbsd(7) for include usage.)

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

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

     #include <grp.h>

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

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

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 representation of the uid, unless the
     argument nouser is non-zero, in which case a null pointer is returned.

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

     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 representation of the gid, unless
     the argument nogroup is non-zero, in which case a null pointer is returned.

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

SEE ALSO

     getgrgid(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 and OpenBSD 6.4.