Help me find where error? After "strcat", data all become 0x00!!!!
 

Hi:

I create a http client to send data to server. The code :

*********************************************************************/
int main(int argc, char *argv[])
{
int sockfd;
char buffer[1024];
struct sockaddr_in server_addr;
//struct hostent *host;
int portnumber,nbytes;
char host_addr[256];
char host_file[1024];
char local_file[256];
FILE * fp;
char *request;
char post[300],host[100],content_len[100];
int send, totalsend;
int i;
char * pt;
char data[19] = {0x41,0x54,0x4d,0x53,0x30,0x31,0x31,0x01,0x01,0x0,0x0,0x0,0x03,0x01,0x0a,0x0a,0x12,0x0f,0x38};

memset(post,0,sizeof(post));
memset(host,0,sizeof(host));
memset(content_len,0,sizeof(content_len));

if(argc!=2)
{
fprintf(stderr,"Usage:%s web-address\a\n",argv[0]);
exit(1);
}
#if debug
printf("parameter.1 is: %s\n", argv[1]);
#endif

GetHost(argv[1], host_addr, host_file, &portnumber);

#if debug
printf("webhost:%s\n", host_addr);
printf("hostfile:%s\n", host_file);
printf("portnumber:%d\n\n", portnumber);
printf("Before socket\n");
#endif

if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
{
fprintf(stderr,"Socket Error:%s\a\n",strerror(errno));
exit(1);
}

bzero(&server_addr,sizeof(server_addr));
server_addr.sin_family=AF_INET;
server_addr.sin_port=htons(portnumber);
//server_addr.sin_addr=*((struct in_addr *) host->h_addr);
server_addr.sin_addr.s_addr=inet_addr(host_addr);

if(connect(sockfd,(struct sockaddr *)(&server_addr),sizeof(struct sockaddr))==-1)
{
fprintf(stderr,"Connect Error:%s\a\n",strerror(errno));
exit(1);
}
/*
sprintf(request,"POST /%s HTTP/1.1\r\n\
Host:%s:%d\r\n\
Content-Length: 7\r\n\
Cache-Control: no-cache\r\n\r\nHello!",host_file,host_addr,portnumber);
*/
sprintf(post,"POST /%s HTTP/1.1\r\n",host_file);
sprintf(host,"Host:%s:%d\r\n",host_addr,portnumber);
sprintf(content_len,"Content-Length:%d\r\n\r\n",19);

nbytes = strlen(post)+strlen(host)+strlen(content_len)+19+1;
request = (char *)malloc(nbytes);
if(request==NULL)
{
return -1;
}
memcpy(request,post,strlen(post));
strcat(request,host);
strcat(request,content_len);
strcat(request,data);

printf("%s", request);

for(i=0;i<nbytes;i++)
printf("%02x ",request[i]);
printf("\n");

…………

result is :
50 4f 53 54 20 2f 6c 69 66 74 2f 66 61 75 6c 74 54 72 61 6e 73 66 2f 20 48 54 54 50 2f 31 2e 31 0d 0a 48 6f 73 74 3a 31 39 32 2e 31 36 38 2e 31 2e 31 37 32 3a 38 30 38 30 0d 0a 43 6f 6e 74 65 6e 74 2d 4c 65 6e 67 74 68 3a 31 39 0d 0a 0d 0a 41 54 4d 53 30 31 31 01 01 00 00 00 00 00 00 00 00 00 00 00

but the data is 0x41,0x54,0x4d,0x53,0x30,0x31,0x31,0x01,0x01,0x0,0x0,0x0,0x03,0x01,0x0a,0x0a,0x12,0x0f,0x38

Help me ! thanks!

Doesn't a null character (i.e 0x00) terminate a string? If so strcat() is probably the wrong function.

The problem is in request = (char *)malloc(nbytes);

Allocate more memory and check

Hi,Thanks all the same!

I have fixed the question:

All "strcat" are replaced with “memcpy”.