int
main(int argc, char *argv[])
{
if (argc < 4 || (strcmp(argv[1], "p") != 0 && strcmp(argv[1], "u") != 0)) {
printf(1, "usage: prot [p|u] pathname password\n");
exit();
}
if (strcmp(argv[1], "p") == 0) {
printf(1, "Locking %s with %s...\n", argv[2], argv[3]);
fprot(argv[2], argv[3]);
} else if (strcmp(argv[1], "u") == 0) {
printf(1, "Unlocking %s with %s...\n", argv[2], argv[3]);
funprot(argv[2], argv[3]);
}
exit();
}
int
main(int argc, char *argv[])
{
int fd = open("README", O_RDWR);
close(fd);
printf(1,"a.txt===>%d\n",fd);
// father put password
int res = fprot("README", "12345678");
printf(1,"set password: ==> %d\n",res);
int id= fork();
if (id==0){
res = funprot("README", "12345678");
//res = funlock("README", "12345678");
printf(1,"funlock\\funprot right password ==> %d\n",res);
fd = open("README", O_RDONLY);
printf(1,"printing first 30 chars of file, fd is ==> %d\n",fd);
char buf[31];
read(fd,buf,30);
printf(1,"%s\n",buf);
close(fd);
exit();
}
else{
wait();
fd = open("README", O_RDONLY);
if (fd>0) {
printf(1,"printing first 30 chars of file, fd is ==> %d\n",fd);
char buf[31];
read(fd,buf,30);
printf(1,"%s\n",buf);
close(fd);
}
else
printf(1,"error opening file\n");
exit();
}
exit();
}
int
main(int argc, char *argv[])
{
if(argc !=3){
printf(2,"Usage: test2 pathname password\n");
exit();
}
char * pathname = argv[1];
char * password = argv[2];
char buf[BUF_SIZE];
int pid,unlock, fd, prot,br,unprot;
// locks file with password
printf(1, "Attempting to protect %s with password %s\n", pathname, password);
if((prot = fprot(pathname, password)) < 0){
printf(1,"protection failed: %d\n" ,prot);
exit();
}
printf(1,"protection successful\n");
if((pid = fork()) == 0){ // child process
printf(1, "Child attempting to unlock %s\n", pathname);
// unlocks file
if((unlock = funlock(pathname,password)) < 0){
printf(1,"child: unlock failed: %d\n" ,unlock);
exit();
}
printf(1,"child: unlock successful\n");
// open file to read
printf(1, "Child attempting to open unlocked file %s\n", pathname);
if((fd = open(pathname, O_RDONLY)) < 0){
printf(1,"child: open failed\n");
exit();
}
printf(1,"child: open successful\nchild: file contents are:\n");
// reads contents.
while((br = read(fd, buf, BUF_SIZE)) > 0){
printf(1,"%s",buf); // prints to screen
}
printf(1,"\nchild: finished reading\n");
// close file
if(close(fd) < 0){
printf(1,"child: close failed\n");
exit();
}
printf(1,"\nchild: closed file\n");
exit();
} else { // parent process
wait(); // wait for child
// open file
if((fd = open(pathname, O_RDONLY)) >= 0){
printf(1,"parent: open successful\n");
exit();
}
printf(1,"parent: open failed\nparent: now cat supposed to fail\n");
// read using cat while still protected
cat(fd); // supposed to fail
// unprotect
if((unprot = funprot(pathname,password)) < 0){
printf(1,"parent: unprot failed: %d\n" ,unprot);
exit();
}
printf(1,"parent: unprotect successful\nparent: now cat supposed to succeed\n");
cat(fd); // supposed to succeed
}
printf(1,"Test Passed\n");
exit();
}
