获取主机和用户信息

#include  <sys/types.h>

#include  <sys/utsname.h>

#include <pwd.h>

#include <stdio.h>

#include  <unistd.h>

#include <stdlib.h>

int main(int argc,char * argv[])

{

     char computer[256];

     struct utsname uts;

     if(gethostname(computer,255)!=0||uname(&uts)<0)

     {

         fprintf(stderr,"could not get host information\n");

         exit(1);

     }

     printf("computer name is %s\n",computer);

     printf("system  is %s on %s handware\n",uts.sysname,uts.machine);

     printf("nodename is %s\n",uts.nodename);

     printf("version is %s,%s\n",uts.release,uts.version);

     printf("domainname is %s\n",uts.domainname);

////////////////////////////////////////////////////////////////////////

     uid_t uid;

     gid_t gid;

     struct passwd *pw;

     uid=getuid();

     gid=getgid();

     printf("user is %s\n",getlogin());

     printf("user IDs:uid= %d, gid=%d\n",uid,gid);

     pw=getpwuid(uid);

     printf("UID passwd entry:\n name=%s, uid=%d,  gid=%d, home=%s, shell=%s\n",

            pw->pw_name,pw->pw_uid,pw->pw_gid,pw->pw_dir,pw->pw_shell);

     pw=getpwnam("root");

     printf("UID passwd entry:\n name=%s, uid=%d,  gid=%d, home=%s, shell=%s\n",

            pw->pw_name,pw->pw_uid,pw->pw_gid,pw->pw_dir,pw->pw_shell);

      exit(0);

}