Expected token error in file RecvFile function - c++

Question

I'm learning some examples about C++ socket. One of the code here has an error : "expect token while got fclose" at the line above the last line
The code seems fine with me, so I can't figure out what is wrong here.
Any ideas are appreciated.
void RecvFile(int sock, const char* filename)
{
int rval;
char buf[0x1000];
FILE *file = fopen(filename, "wb");
if (!file)
{
printf("Can't open file for writing");
return;
}
do
{
rval = recv(sock, buf, sizeof(buf), 0);
if (rval < 0)
{
// if the socket is non-blocking, then check
// the socket error for WSAEWOULDBLOCK/EAGAIN
// (depending on platform) and if true then
// use select() to wait for a small period of
// time to see if the socket becomes readable
// again before failing the transfer...
printf("Can't read from socket");
fclose(file);
return;
}
if (rval == 0)
break;
int off = 0;
do
{
int written = fwrite(&buf[off], 1, rval - off, file);
if (written < 1)
{
printf("Can't write to file");
fclose(file);
return;
}
off += written;
}
while (off < rval);
}
fclose(file);
}

Answer 1

You have a do with no corresponding while:
do
{
// ...
do
{
// ...
}
while (off < rval);
}
// No while here
fclose(file);
It appears that it should just be while (true), which you might as well just stick at the top, instead of doing a do while. Execution will break from the loop if recv returns 0 or less, which indicate an orderly shutdown and an error respectively. So change it to:
while (true)
{
// ...
do
{
// ...
}
while (off < rval);
}
fclose(file);

Answer 2

You have a do statement without a corresponding while:
do // <== THERE IS NO CORRESPONDING while FOR THIS do
{
rval = recv(sock, buf, sizeof(buf), 0);
if (rval < 0)
{
// ...
}
// ...
do
{
// ...
}
while (off < rval); // <== This is OK: the "do" has a matching "while"
}
// Nothing here! Should have a "while (condition)"
If you just want to repeat your loop indefinitely, then you should use while (true) - either replacing the do keyword (preferably), or adding it where the missing while should go (as indicated by the above comments).

Answer 3

You started a do without actually supplying a while();
do
{
rval = recv(sock, buf, sizeof(buf), 0);
if (rval < 0)
{
// if the socket is non-blocking, then check
// the socket error for WSAEWOULDBLOCK/EAGAIN
// (depending on platform) and if true then
// use select() to wait for a small period of
// time to see if the socket becomes readable
// again before failing the transfer...
printf("Can't read from socket");
fclose(file);
return;
}
if (rval == 0)
break;
int off = 0;
do
{
int written = fwrite(&buf[off], 1, rval - off, file);
if (written < 1)
{
printf("Can't write to file");
fclose(file);
return;
}
off += written;
}
while (off < rval);
} //while() Needs to go here
fclose(file);