the user whose password should be verified
the realm the user is in
the plaintext password to verify
Retruns TRUE if passwords equal, FALSE if they don't, or PEAR_Error on failure.
Table 37-1. Possible PEAR_Error values
| Error Code | Summary |
|---|---|
| FILE_PASSWD_E_USER_NOT_IN_REALM | the specified user doesn't exist in the supplied realm |