tailieunhanh - Red Hat Linux 7.2 Bible, Unlimited ed phần 8

Mô-đun trong thư mục đó sau đó có thể được tải và bốc dỡ khi cần thiết. Chú ý: Trong các phiên bản trước, Red Hat Linux được lưu trữ mô-đun trong thư mục lib / / thư mục module, chứ không phải là thư mục / lib/moduels/ *. Cấu trúc này cho phép | Configuring sendmail If you ever find the need to strike up a conversation with a system administrator simply mention file address rewriting rules or mail loops back to itself and you will be instantly understood considered a compatriot and find yourself the recipient of much sympathy. The file or sendmail configuration file is legendary and infamous for arcane syntax nearly indecipherable rule sets and its capability to make an administrator tear out his or her hair. In reality some of this reputation is earned and well deserved but configuring sendmail has gotten much easier in the past few years with the advent of m4 preprocessor macros which are discussed at the end of this section. Even better the default etc file that is included in the sendmail RPM will likely work without modification although a small amount of tweaking should be performed anyway. The file etc contains the configuration information and optional values used to direct the behavior of the sendmail daemon. The entire file is well over 1 000 lines in length at least half of which are not discussed here and you are to be pitied if you ever find the need to manipulate those lines . Some potentially useful lines are presented in the sections that follow with comments interjected after related blocks of options. The generic format of the file is a single-letter command followed by a parameter usually represented by a single letter although not necessarily . For example options are preceded by a capital O for option . If a value is required this is specified last. The command must start in the first column of the line because leading white space indicates a continuation of the previous line. Also only one command may exist on a single line. The valid commands are described in Table 19-3. Lines that begin with a are considered comments and are not processed. Table 19-3 Commands Available in etc Command Description C Defines a .