cannot look at specific char returned by recv

Question

I need to read in only the values of a header that terminate with \\r\\n\\r\\n

Something like GETFILE OK 1024\\r\\n\\r\\n <content>

I'm trying to get the first \\r\\n and then get the next pair in a subsequent recv call. The call to this function is: read_in_header(gfr, headerRecvBuff, 1);

Issue: The logic in the while referring to \\n is completely ignored, or does not show any matches, when I know they exist. Is this the right way to compare the char newline?

int read_in_header(gfcrequest_t *gfr, char *buf, int len) {
char *s = buf;
int slen = len;
int c = 0;
int count = 0;
//get the first \r\n pair
do {
    c = recv(gfr->client_fd, s, slen, 0);
    printf("checking to see what s has now: %s\n", s);
    count += c;
} while ((c > 0) && (s[count - 1] != '\n'));

//get the second \r\n pair
count = 0;
do {
    c = recv(gfr->client_fd, s, slen, 0);
    printf("checking to see what s has now: %s\n", s);
    count += c;
} while ((c > 0) && (s[count - 1] != '\n'));

printf("checking to see what s has now: %s\n", s);


if (c < 0) {
    return c;
} else if (c == 0) {
    puts("Time to disconnect, the server is done.");
    //total bytes received should not include header length
    gfr->totalbytesReceived -= gfr->headerbytes_received;
    return 0;
} else {
    s[c - 1] = '\0';
}
gfr->totalbytesReceived += count;
return c;
}

Answer 1

Regarding Is this the right way to compare the char newline?

Since s is a buffer (not a single char), for the first loop the comparison method can be changed to

while ((c > 0) && (strstr(s, "\r\n") == NULL));

To require both "\\r" & "\\n" are there. This takes advantage of string searching to check both values are present in one line.

resulting in:

do {
    c = recv(gfr->client_fd, s, slen, 0);
    printf("checking to see what s has now: %s\n", s);
    //  count += c; //not needed
} while ((c > 0) && (strstr(s, "\r\n") == NULL));

If you decided to capture the line that has all 4, ie \\r\\n\\r\\n , then make that the argument of the comparison.

One side note, unless you have set socket options to non-blocking, recv() is a blocking call. Look into how to set a socket to non-blocking