3. The length of the link is 3600m and the propagation speed is 3*10^8 m/s.
so 3600m/(3*10^8)=0.000036 m/s
distance/(propagation speed)+(file size)/(transmission rate)= ((3600m)/(3*10^8))
+((10MB)
/(1Gbps))
= 0.000036 + 10MB/1Gbps
= 0.000036 + (10*10^6)/(1*10^9) =
0.010036secs for a 10MB to reach the end of a 3600m link with a 1Gbps rate
b) ((2m)/(3*10^8)) + ((10MB)/(10bps)) = 0.010036 + 1,000,000bps
0.010036 + 1,000,000bps
= 1,000,000.010036secs
for a 10MB to reach the end of 2m link with a 10bps rate
4. a) The pipe function needs these
Headers. (in Ubuntu or LINUX platforms only)
#include <unistd.h>
Int pipe(int states[2]);
#define _GNU Source
#include <fcntl.h>
#include <unistd.h>
Int pipe2(int
state[2], int flags);
Functions and
Variables
The pipe() function makes an one-directional path that is
used for IPC. The fork function is very important in network communication, so
the states variable will be determined by the fork function. Then, the states
variable is used to implement two file function at the end of the pipe. When it
is state[-1] it is for the error function. Then if it is state[0] then it means
to fread the end of the pipe. Lastly if it is state[1], it means to write the
end of the pipe. The information in the write function is buffered until it is
used from the read function, so it needs a char buf[]. If it is successful in reading and write the
end of the pipe then it returns 0 by default or does nothing, if not then it
hits the error state.
5. fread and fwrite functions only need headers.
#include <stdio.h>
#imclude <stdlib.h>
Functions
Similar
to OOP you need an object to be associated with the file stream functions. So
the variable for that would be FILE *name.
These FILE stream options are also accompanied by fopen and fclose functions (Used to open and close a file used in the program's scope)
fwrite() functions is used to permanently edit on the corresponding file that was opened.
fread () functions is used to read or scan a file after it's opened depending on what it's looking for and holding that value for later purposes.
Example:
#include <stdio.h>
#include <stdlib.h>
int main (int argc, char *argv[]){
FILE *object;
char buf[100];
size_t sz;
/*Read Function*/
object = fopen(“file.ext”,
“r”);
if (object==NULL){
perror(“fopen”);
exit(1);
}
while(!feof(object))
{ sz= fread((void *) buf, 10, 1, object);
buf[9]=’\0’;
printf(“%s”,buf); }
printf(“\n”);
fclose(object);
/*Write function*/
object1 = fopen(“file.ext”, “w”);
if (object1==NULL){
perror(“fopen”);
exit(1);
}
while(!feof(object1))
{ sz= fread((void *) buf, 10, 1, object1);
buf[9]=’\0’;
printf(“%s”,buf); }
printf(“\n”);
fclose(object1);
return 0;
}
}
