một nhóm các máy chủ trong một mạng. Nó cho phép quản lý tập trung của người sử dụng, các nhóm, và mật khẩu, ví chương trình đơn giản cho phép bạn kiểm tra các giá trị trả về bởi uname (2) được thể hiện trong Ví dụ . Chương trình này gọi uname (2) và sau đó hiển thị nội dung của các thông tin | a group of hosts in a network. It permits a centralized management of users groups and passwords for example. A simple program to permit you to test the values returned by uname 2 is shown in Listing . This program invokes uname 2 and then displays the contents of the information it has returned in the structure utsname. Listing A Simple Test Program for uname 2 1 2 3 Example of uname 2 4 5 include 6 include 7 include 8 include 9 include 10 include sys 11 12 int 13 main int argc char argv 14 int z 15 struct utsname u_name 16 17 z uname u_name 18 19 if z -1 20 fprintf stderr s uname 2 n 21 strerror errno 22 exit 1 23 24 25 printf sysname s n 26 27 printf nodename s n 28 29 printf release s n 30 31 printf version s n 32 33 printf machine s n 34 35 printf domainname s n 36 37 38 return 0 39 The steps used in Listing are as follows Linux Socket Programming by Example - Warren W. Gay 206 1. Allocate a structure u_name to receive the data from uname 2 line 15 . 2. Call upon uname 2 in line 17. 3. Check for and report errors lines 19 to 23 . 4. Report the values returned lines 25 to 36 . The following session output shows how to compile and run the program. The output from the program on the example system tux is also included as an example note that this system is not configured to use NIS @tux make uname gcc -c -D_GNU_SOURCE -Wall -Wreturn-type gcc -o uname @tux . uname sysname Linux nodename tux release version 1 Sun Jul 4 00 28 57 EDT 1999 machine i686 domainname @tux Note Your values might differ substantially from the example shown depending upon how your system is configured. For example the domain name might show an NIS domain name instead of an empty string. Many hobby Linux systems that are not configured to use NIS might show an empty domain name string instead. If .
