C language to obtain the Linux local directory and native information of the small program instance _c language

Small program that shows the directory
shows the applet for the specified directory:

#include <unistd.h> #include <stdio.h> #include <dirent.h> #include <string.h> #include <sys
  /stat.h> #include <stdlib.h> void Printdir (char *dir,int depth) {dir *dp;
  struct Dirent *entry;
 
  struct stat statbuf;
    if (DP = Opendir (dir)) = = NULL) {fprintf (stderr, "Cannot Open Directory:%s\n", dir);
  Return
  } chdir (dir);
    while ((entry = Readdir (DP))!= NULL) {lstat (ENTRY-&GT;D_NAME,&AMP;STATBUF); if (S_isdir (Statbuf.st_mode)) {/*found a directory,but ignore.
      */if (strcmp (".", entry->d_name) = = 0 | | strcmp ("..", entry->d_name) = = 0) {continue;
      printf ("%*s%s/\", Depth, "" ", Entry->d_name);
    /*recurse at a new indent level*/printdir (entry->d_name,depth+4);
    }else{printf ("%*s%s \", Depth, "", entry->d_name);
  int main () {/* Show directory */printf ("Directory scan of/home:\n");
  Printdir ("/home", 0); printf ("Done.")
   
  \ n "); Exit0);
 }

According to the parameters output directory structure

#include <unistd.h> #include <stdio.h> #include <dirent.h> #include <string.h> #include <sys
  /stat.h> #include <stdlib.h> void Printdir (char *dir,int depth) {dir *dp;
  struct Dirent *entry;
 
  struct stat statbuf;
    if (DP = Opendir (dir)) = = NULL) {fprintf (stderr, "Cannot Open Directory:%s\n", dir);
  Return
  } chdir (dir);
    while ((entry = Readdir (DP))!= NULL) {lstat (ENTRY-&GT;D_NAME,&AMP;STATBUF); if (S_isdir (Statbuf.st_mode)) {/*found a directory,but ignore.
      */if (strcmp (".", entry->d_name) = = 0 | | strcmp ("..", entry->d_name) = = 0) {continue;
      printf ("%*s%s/\", Depth, "" ", Entry->d_name);
    /*recurse at a new indent level*/printdir (entry->d_name,depth+4);
    }else{printf ("%*s%s \", Depth, "", entry->d_name);
  int main (int argc, char* argv[]) {/* show directory/char *topdir = ".";
  if (argc >= 2) {topdir = argv[1]; } prinTF ("Directory scan of%s:\n", Topdir);
  Printdir (topdir,0); printf ("Done.")
   
  \ n ");
Exit (0);

 }

Get host basic information
Get host User information:

#include <sys/types.h>
#include <pwd.h>
#include <stdio.h>
#include <unistd.h>
 
int main () {
  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 ("Root passwd entry: \ n");
  printf ("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);
}

To obtain the host's own information:

#include <sys/utsname.h>
#include <unistd.h>
#include <stdio.h>
 
 
int main () {
  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 host name is%s \ n", Computer);
  printf ("System is%s on%s hardware \ n", Uts.sysname, uts.machine);
  printf ("NodeName is%s \ n", uts.nodename);
  printf ("Version is%s,%s \ n", Uts.release, uts.version);
 
  Exit (0);
}