Information Security System Design Foundation Tenth Week study summary

Cp1

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>

#define BUFFERSIZE 4096
#define Copymode 0644

void oops (char *, char *);

int main (int argc, char *argv[])
{
int in_fd, OUT_FD, N_chars;
Char Buf[buffersize];
if (argc! = 3) {
fprintf (stderr, "Usage:%s source destination\n", *argv);
Exit (1);
}

if ((in_fd = open (argv[1], o_rdonly)) = =-1)
Oops ("Cannot open", argv[1]);

if ((out_fd = creat (argv[2], copymode)) = = =-1)
Oops ("Cannot creat", argv[2]);

while ((N_chars = Read (IN_FD, buf, buffersize)) > 0)
if (Write (OUT_FD, buf, n_chars)! = n_chars)
Oops ("Write error to", Argv[2]);
if (N_chars = =-1)
Oops ("Read error from", Argv[1]);

if (Close (in_fd) = =-1 | | close (OUT_FD) = =-1)
Oops ("Error Closing Files", "");
}

void oops (char *s1, char *s2)
{
fprintf (stderr, "Error:%s", S1);
Perror (S2);
Exit (1);
}

Ls1

#include <stdio.h>
#include <sys/types.h>
#include <dirent.h>

void Do_ls (char []);

int main (int argc, char *argv[])
{
if (argc = = 1)
Do_ls (".");
Else
while (--ARGC) {
printf ("%s:\n", *++ARGV);
Do_ls (*ARGV);
}

return 0;

}

void Do_ls (char dirname[])
{
Dir*dir_ptr;
struct DIRENT*DIRENTP;

if ((Dir_ptr = Opendir (dirname)) = = NULL)
fprintf (stderr, "Ls1:cannot open%s\n", dirname);
Else
{
while ((DIRENTP = Readdir (dir_ptr)) = NULL)
printf ("%s\n", direntp->d_name);
Closedir (DIR_PTR);
}
}

Ls2

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>

void Do_ls (char[]);
void Dostat (char *);
void Show_file_info (char *, struct stat *);
void Mode_to_letters (int, char []);
Char *uid_to_name (uid_t);
Char *gid_to_name (gid_t);

int main (int argc, char *argv[])
{
if (argc = = 1)
Do_ls (".");
Else
while (--ARGC) {
printf ("%s:\n", *++ARGV);
Do_ls (*ARGV);
}

return 0;
}

void Do_ls (char dirname[])
{
Dir*dir_ptr;
struct DIRENT*DIRENTP;

if ((Dir_ptr = Opendir (dirname)) = = NULL)
fprintf (stderr, "Ls1:cannot open%s\n", dirname);
Else
{
while ((DIRENTP = Readdir (dir_ptr)) = NULL)
Dostat (Direntp->d_name);
Closedir (DIR_PTR);
}
}

void Dostat (char *filename)
{
struct STAT info;

if (stat (filename, &info) = =-1)
perror (filename);
Else
Show_file_info (filename, &info);
}

void Show_file_info (char *filename, struct stat *info_p)
{
Char*uid_to_name (), *ctime (), *gid_to_name (), *filemode ();
Voidmode_to_letters ();
Char modestr[11];

Mode_to_letters (Info_p->st_mode, MODESTR);

printf ("%s", MODESTR);
printf ("%4d", (int) info_p->st_nlink);
printf ("%-8s", Uid_to_name (Info_p->st_uid));
printf ("%-8s", Gid_to_name (Info_p->st_gid));
printf ("%8ld", (long) info_p->st_size);
printf ("%.12s", 4+ctime (&info_p->st_mtime));
printf ("%s\n", filename);

}

void Mode_to_letters (int mode, char str[])
{
strcpy (str, "----------");

if (S_isdir (mode)) str[0] = ' d ';
if (S_ISCHR (mode)) str[0] = ' C ';
if (s_isblk (mode)) str[0] = ' B ';

if (Mode & S_IRUSR) str[1] = ' R ';
if (Mode & S_IWUSR) str[2] = ' W ';
if (Mode & S_IXUSR) str[3] = ' x ';

if (Mode & S_IRGRP) str[4] = ' R ';
if (Mode & S_IWGRP) str[5] = ' W ';
if (Mode & S_IXGRP) str[6] = ' x ';

if (Mode & S_iroth) str[7] = ' R ';
if (Mode & S_iwoth) str[8] = ' W ';
if (Mode & S_ixoth) str[9] = ' x ';
}

#include <pwd.h>

Char *uid_to_name (uid_t uid)
{
STRUCTPASSWD *getpwuid (), *pw_ptr;
static Char numstr[10];

if ((pw_ptr = Getpwuid (uid)) = = = NULL) {
sprintf (Numstr, "%d", UID);
return numstr;
}
Else
return pw_ptr->pw_name;
}

#include <grp.h>

Char *gid_to_name (gid_t GID)
{
struct group *getgrgid (), *grp_ptr;
static Char numstr[10];

if ((grp_ptr = Getgrgid (gid)) = = NULL) {
sprintf (Numstr, "%d", GID);
return numstr;
}
Else
Return grp_ptr->gr_name;
}

Who1

#include <stdio.h>
#include <stdlib.h>
#include <utmp.h>
#include <fcntl.h>
#include <unistd.h>

#defineSHOWHOST

int show_info (struct utmp *UTBUFP)
{
printf ("%-8.8s", utbufp->ut_name);
printf ("");
printf ("%-8.8s", utbufp->ut_line);
printf ("");
printf ("%10ld", utbufp->ut_time);
printf ("");
#ifdefSHOWHOST
printf ("(%s)", utbufp->ut_host);
#endif
printf ("\ n");

return 0;
}
int main ()
{
struct UTMP Current_record;
INTUTMPFD;
Intreclen = sizeof (Current_record);

if ((UTMPFD = open (Utmp_file, o_rdonly)) = =-1) {
Perror (Utmp_file);
Exit (1);
}
while (read (UTMPFD, &current_record, reclen) = = Reclen)
Show_info (&current_record);
Close (UTMPFD);
return 0;
}

Who2

#include <stdio.h>
#include <stdlib.h>
#include <utmp.h>
#include <fcntl.h>
#include <unistd.h>

#defineSHOWHOST

int show_info (struct utmp *UTBUFP)
{
printf ("%-8.8s", utbufp->ut_name);
printf ("");
printf ("%-8.8s", utbufp->ut_line);
printf ("");
printf ("%10ld", utbufp->ut_time);
printf ("");
#ifdefSHOWHOST
printf ("(%s)", utbufp->ut_host);
#endif
printf ("\ n");

return 0;
}
int main ()
{
struct UTMP Current_record;
INTUTMPFD;
Intreclen = sizeof (Current_record);

if ((UTMPFD = open (Utmp_file, o_rdonly)) = =-1) {
Perror (Utmp_file);
Exit (1);
}
while (read (UTMPFD, &current_record, reclen) = = Reclen)
Show_info (&current_record);
Close (UTMPFD);
return 0;
}

Echostate

#include <stdio.h>
#include <stdlib.h>
#include <termios.h>

int main ()
{
struct Termios info;
int RV;

RV = tcgetattr (0, &info); /* Read values from driver */

if (rv = =-1) {
Perror ("tcgetattr");
Exit (1);
}
if (Info.c_lflag & ECHO)
printf ("Echo is on, since it bit is 1\n");
Else
printf ("Echo is OFF, since it bit is 0\n");

return 0;
}

Setecho

#include <stdio.h>
#include <stdlib.h>
#include <termios.h>

#define OOPS (s,x) {perror (s); exit (x);}

int main (int argc, char *argv[])
{
struct Termios info;

if (argc = = 1)
Exit (0);

if (tcgetattr (0,&info) = =-1)/* Get attribs */
Oops ("Tcgettattr", 1);

if (argv[1][0] = = ' Y ')
Info.c_lflag |= ECHO; /* Turn on bit */
Else
Info.c_lflag &= ~echo; /* Turn off bit */

if (tcsetattr (0,tcsanow,&info) = =-1)/* Set Attribs */
Oops ("Tcsetattr", 2);

return 0;
}

FileInfo

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>

void Show_stat_info (char *, struct stat *);

int main (int argc, char *argv[])
{
struct STAT info;

if (argc>1)
{

if (stat (argv[1], &info)! =-1) {
Show_stat_info (argv[1], &info);
return 0;
}
Else
Perror (argv[1]);
}
return 1;
}
void Show_stat_info (char *fname, struct stat *buf)
{
printf ("Mode:%o\n", Buf->st_mode);
printf ("Links:%d\n", Buf->st_nlink);
printf ("User:%d\n", buf->st_uid);
printf ("Group:%d\n", Buf->st_gid);
printf ("Size:%d\n", (int) buf->st_size);
printf ("Modtime:%d\n", (int) buf->st_mtime);
printf ("Name:%s\n", fname);
}

FileSize

#include <stdio.h>
#include <sys/stat.h>

int main ()
{
struct stat infobuf;

if (Stat ("/etc/passwd", &infobuf) = =-1)
Perror ("/etc/passwd");
Else
printf ("The size of/etc/passwd is%d\n", infobuf.st_size);
}

Spwd

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>

Ino_tget_inode (char *);
void Printpathto (ino_t);
void Inum_to_name (ino_t, char *, int);

int main ()
{
Printpathto (Get_inode ("."));
Putchar (' \ n ');
return 0;
}

void Printpathto (ino_t this_inode)
{
Ino_tmy_inode;
Charits_name[bufsiz];

if (Get_inode (".")! = This_inode)
{
ChDir ("..");

Inum_to_name (This_inode,its_name,bufsiz);

My_inode = Get_inode (".");
Printpathto (My_inode);
printf ("/%s", its_name);

}
}

void Inum_to_name (ino_t inode_to_find, char *namebuf, int buflen)
{
Dir*dir_ptr;
struct DIRENT*DIRENTP;

Dir_ptr = Opendir (".");
if (dir_ptr = = NULL) {
Perror (".");
Exit (1);
}

while ((DIRENTP = Readdir (dir_ptr)) = NULL)
if (Direntp->d_ino = = Inode_to_find)
{
strncpy (Namebuf, Direntp->d_name, Buflen);
Namebuf[buflen-1] = ' + ';
Closedir (DIR_PTR);
Return
}
fprintf (stderr, "error looking for Inum%d\n", (int) inode_to_find);
Exit (1);
}

ino_t Get_inode (char *fname)
{
struct STAT info;

if (stat (fname, &info) = =-1) {
fprintf (stderr, "cannot stat");
Perror (fname);
Exit (1);
}
return Info.st_ino;
}

Testioctl

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>

int main ()
{
struct winsize size;
if (Isatty (stdout_fileno) = = 0)
Exit (1);
if (IOCTL (Stdout_fileno, Tiocgwinsz, &size) < 0) {
Perror ("IOCTL Tiocgwinsz error");
Exit (1);
}

printf ("%d rows%d columns\n", Size.ws_row, Size.ws_col);
return 0;
}

Information Security System Design Foundation Tenth Week study summary