C++ Programming :: How to empty the variable buffer in recv() before accepting a string.


	How to empty the variable buffer in recv() before accepting a string. Hi I am using recv() from socket.h in one of my TCP-client projects. The problem is that the buffer variable in recv(socketDescriptor, buffer, flags) points to some stray location and when the incoming string is filled into it, there are trailing junk characters also. The code portion refering to it is somewhat like: int rcvStatus; char buffer; rcvStatus = recv(socketDescriptor, buffer, flags); std::cout<< buffer << std::endl; If I initialize the buffer variable to NULL or "0", the recv() returns -1, that is it doesn't accept the incoming string. So, Please help me to clean the buffer variable, before it is being filled with the incoming string. Thanks Aditya the following will work: int len = 1024; char buffer[1024 + 1]; len = recv(socketDescriptor, buffer, len,flags); if (len > 0){ //there is actual data received. buffer[len] = '\0'; //process the data in buffer. }else if (len == 0){ //the connection has closed. }else{ //unknown error occur. } On 5 29 , 12 55 , Aditya <adityagupta@gmail.com> wrote: - Hide quoted text - > Hi > I am using recv() from socket.h in one of my TCP-client projects. > The problem is that the buffer variable in recv(socketDescriptor, > buffer, flags) points to some stray location and when the incoming > string is filled into it, there are trailing junk characters also. > The code portion refering to it is somewhat like: > int rcvStatus; > char buffer; > rcvStatus = recv(socketDescriptor, buffer, flags); > std::cout<< buffer << std::endl; > If I initialize the buffer variable to NULL or "0", the recv() returns > -1, that is it doesn't accept the incoming string. > So, Please help me to clean the buffer variable, before it is being > filled with the incoming string. > Thanks > Aditya On May 28, 9:55 pm, Aditya <adityagupta@gmail.com> wrote: > Hi > I am using recv() from socket.h in one of my TCP-client projects. > The problem is that the buffer variable in recv(socketDescriptor, > buffer, flags) points to some stray location and when the incoming > string is filled into it, there are trailing junk characters also. > The code portion refering to it is somewhat like: > int rcvStatus; > char buffer; > rcvStatus = recv(socketDescriptor, buffer, flags); What is the size of the buffer? Typically you should allocate a buffer of some size either on the stack or heap and then pass this size to recv as the 3rd arg. recv on success returns the number of bytes received. You should then read only those many bytes from the buffer passed to recv. Hope his helps. - Hide quoted text - > std::cout<< buffer << std::endl; > If I initialize the buffer variable to NULL or "0", the recv() returns > -1, that is it doesn't accept the incoming string. > So, Please help me to clean the buffer variable, before it is being > filled with the incoming string. > Thanks > Aditya Aditya wrote: > Hi > I am using recv() from socket.h in one of my TCP-client projects. Please don't multi-post on Usenet, as you where told elsewhere, this belongs on comp.unix.programmer. -- Ian Collins. On May 29, 10:18 am, Archie <nraut@gmail.com> wrote: - Hide quoted text - > On May 28, 9:55 pm, Aditya <adityagupta@gmail.com> wrote: > > Hi > > I am using recv() from socket.h in one of my TCP-client projects. > > The problem is that the buffer variable in recv(socketDescriptor, > > buffer, flags) points to some stray location and when the incoming > > string is filled into it, there are trailing junk characters also. > > The code portion refering to it is somewhat like: > > int rcvStatus; > > char buffer; > > rcvStatus = recv(socketDescriptor, buffer, flags); > What is the size of the buffer? Typically you should allocate a > buffer of some size either on the stack or heap and then pass this > size to recv as the 3rd arg. recv on success returns the number of > bytes received. You should then read only those many bytes from the > buffer passed to recv. Hope his helps. > > std::cout<< buffer << std::endl; > > If I initialize the buffer variable to NULL or "0", the recv() returns > > -1, that is it doesn't accept the incoming string. > > So, Please help me to clean the buffer variable, before it is being > > filled with the incoming string. > > Thanks > > Aditya- Hide quoted text - > Hi Thanks That Helps....