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@(#)pwcache.3 8.1 (Berkeley) 6/9/93
.Dd October 19, 2012 .Dt PWCACHE 3 .Os .Sh NAME .Nm pwcache , .Nm user_from_uid , .Nm group_from_gid .Nd cache password and group entries .Sh LIBRARY .Lb libc .Sh SYNOPSIS n pwd.h .Ft const char * .Fn user_from_uid "uid_t uid" "int nouser" .Ft int .Fn uid_from_user "const char *name" "uid_t *uid" .Ft int .Fn pwcache_userdb "int (*setpassent)(int)" "void (*endpwent)(void)" "struct passwd * (*getpwnam)(const char *)" "struct passwd * (*getpwuid)(uid_t)" n grp.h .Ft const char * .Fn group_from_gid "gid_t gid" "int nogroup" .Ft int .Fn gid_from_group "const char *name" "gid_t *gid" .Ft int .Fn pwcache_groupdb "int (*setgroupent)(int)" "void (*endgrent)(void)" "struct group * (*getgrnam)(const char *)" "struct group * (*getgrgid)(gid_t)" .Sh DESCRIPTION The .Fn user_from_uid function returns the user name associated with the argument .Fa uid . The user name is cached so that multiple calls with the same .Fa uid do not require additional calls to .Xr getpwuid 3 . If there is no user associated with the .Fa uid , a pointer is returned to a string representation of the .Fa uid , unless the argument .Fa nouser is non-zero, in which case a .Dv NULL pointer is returned.
p The .Fn group_from_gid function returns the group name associated with the argument .Fa gid . The group name is cached so that multiple calls with the same .Fa gid do not require additional calls to .Xr getgrgid 3 . If there is no group associated with the .Fa gid , a pointer is returned to a string representation of the .Fa gid , unless the argument .Fa nogroup is non-zero, in which case a .Dv NULL pointer is returned.
p The .Fn uid_from_user function returns the uid associated with the argument .Fa name . The uid is cached so that multiple calls with the same .Fa name do not require additional calls to .Xr getpwnam 3 . If there is no uid associated with the .Fa name , the .Fn uid_from_user function returns -1; otherwise it stores the uid at the location pointed to by .Fa uid and returns 0.
p The .Fn gid_from_group function returns the gid associated with the argument .Fa name . The gid is cached so that multiple calls with the same .Fa name do not require additional calls to .Xr getgrnam 3 . If there is no gid associated with the .Fa name , the .Fn gid_from_group function returns -1; otherwise it stores the gid at the location pointed to by .Fa gid and returns 0.
p The .Fn pwcache_userdb function changes the user database access routines which .Fn user_from_uid and .Fn uid_from_user call to search for users. The caches are flushed and the existing .Fn endpwent method is called before switching to the new routines. .Fa getpwnam and .Fa getpwuid must be provided, and .Fa setpassent and .Fa endpwent may be .Dv NULL pointers.
p The .Fn pwcache_groupdb function changes the group database access routines which .Fn group_from_gid and .Fn gid_from_group call to search for groups. The caches are flushed and the existing .Fn endgrent method is called before switching to the new routines. .Fa getgrnam and .Fa getgrgid must be provided, and .Fa setgroupent and .Fa endgrent may be .Dv NULL pointers. .Sh SEE ALSO .Xr getgrgid 3 , .Xr getgrnam 3 , .Xr getpwnam 3 , .Xr getpwuid 3 .Sh HISTORY The .Fn user_from_uid and .Fn group_from_gid functions first appeared in x 4.4 .
p The .Fn uid_from_user and .Fn gid_from_group functions first appeared in .Nx 1.4 .
p The .Fn pwcache_userdb and .Fn pwcache_groupdb functions first appeared in .Nx 1.6 and .Fx 10.0 .