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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();
void mode_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 )
{
struct passwd *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>

#define SHOWHOST

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(" ");
#ifdef SHOWHOST
printf("(%s)", utbufp->ut_host);
#endif
printf("\n");

return 0;
}
int main()
{
struct utmp current_record;
int utmpfd;
int reclen = 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>

#define SHOWHOST

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(" ");
#ifdef SHOWHOST
printf("(%s)", utbufp->ut_host);
#endif
printf("\n");

return 0;
}
int main()
{
struct utmp current_record;
int utmpfd;
int reclen = 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 its bit is 1\n");
else
printf(" echo is OFF, since its 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_t get_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_t my_inode ;
char its_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] = ‘\0‘;
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;
}

信息安全系统设计基础第十周学习总结

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原文地址：http://www.cnblogs.com/20135310cqr/p/4966435.html