Question

how do I allocate memory for strlen(esc) in a proper way? The temp and str are char datatypes.

double esc = t1.tv_sec+(t1.tv_usec/1000000.0);
strAll = malloc(strlen(temp) + strlen(str) + strlen(esc) + 1);

Answer 1

You cannot take strlen(esc). As I am sure the compiler has already told you, the argument to strlen() must be char *, you are passing it a double. Try first converting the double to array of char with snprintf().