c++ socket binary file - c++

Question

i have this function to get the content of file ,
#define BUFSIZE 512
vector<int> getContFile(char* pFile) {
ifstream vCin(pFile, ios::binary);
ifstream::pos_type size;
// get vLength of file:
vCin.seekg(0, ios::end);
size = vCin.tellg();
vCin.seekg(0, ios::beg);
vector<int> vTmp;
for (int i = 0; i < size; i++)
vTmp.push_back(vCin.get());
vCin.close();
return vTmp;
}
and this to send to the server
void SendFile() {
SendS("upFileUser");
int i;
vector<int> vTmp = getContFile("/usr/home/alex/Desktop/eval.tar");
for (i = 0; i < vTmp.size(); i += BUFSIZE) {
char *vBuff = new char[BUFSIZE];
for (int j = i; j < BUFSIZE; j++)
vBuff[j] = (char(vTmp[i]));
SendS(vBuff);
}
if (i < (vTmp.size() - 1)) {
char *vBuff = new char[vTmp.size() - i];
for (int j = 0; j < vTmp.size() - i; j++)
vBuff[j + i] = (char(vTmp[j + i]));
SendS(vBuff);
}
sendS("endOfFileTransmision");
}
void SendS(char* pSir) {
int vLen = strlen(pSir);
write(pSocket, &vLen, sizeof (int));
write(pSocket, pSir, vLen);
}
this is the receve function
char* reciveS() {
char* vTmp;
int vCt = 0;
read(pSocket, &vCt, sizeof (vCt));
if (vCt != 0) {
vTmp = new char[vCt];
read(vSocket, vTmp, vCt);
} else {
vTmp = NULL;
}
return vTmp;
}
bool receveFile(void) {
char* vReceve = reciveS();
if (strcmp(vReceve, "upFileUser") == 0)
{
ofstream vCoutFile;
vCoutFile.open("data2.tar", ios::out | ios::binary);
while (true) {
char *vTmp = new char[BUFSIZ];
vTmp = reciveS();
cout<<vTmp;
if (strcmp(vTmp, "endOfFileTransmision") == 0) break;
else {
cout << vTmp;
vCoutFile << vTmp;
}
}
vCoutFile.close();
}
}
and the result are a broke pipe(i run this to freebsd 6.4 amd with g++ compiler) , so what i miss , the connection are good i can transfer text from client to server and reverse the problem are with binary file

Answer 1

I see two problems with your code:
You are making a lot of allocations (new) but you never free the memory.
In the SendS function you are taking the string length, but the data in that "string" is from a vector of integers and is binary. This means that the data can contain the string-terminating '\0' character (the integer 0).
Besides that, I really don't follow what you are doing. Instead of reading into a vector, create a char-buffer and allocate enough memory to put the whole file into that buffer (char *buffer = new char[length_of_file]) and send it, with the length of the buffer first.
Something like this:
std::pair<size_t, char *> getContFile(const char *pFile)
{
ifstream vCin(pFile, ios::binary);
ifstream::pos_type size;
vCin.seekg(0, ios::end);
size = vCin.tellg();
vCin.seekg(0, ios::beg);
char *buffer = new char[size];
vCin.read(buffer, size);
return std::make_pair(static_cast<size_t>(size), buffer);
}
void SendFile()
{
SendS("upFileUser", strlen("upFileUser"));
std::pair<size_t, char *> vTmp = getContFile("/usr/home/alex/Desktop/eval.tar");
SendS(vTmp.second, vTmp.first);
delete [] vTmp.second;
}
void SendS(char *buffer, size_t length)
{
// Send the length
size_t tmp = htonl(length);
write(pSocket, &tmp, sizeof(tmp));
// Send the buffer
while (length > 0)
{
ssize_t sent = write(pSocket, buffer, length);
if (sent <= 0)
{
// Some kind of error
break;
}
buffer += sent;
length -= sent;
}
}
Do something similar on the receiving side.