rax_string_catf

rax_string_t rax_string_catf(rax_string_t *to_string,
 const char *format_string,
 ...); 
 

Append to to_string a string that is created from the format string and the following parameters. The format string is interpreted in the same way as the format string in C's printf function. The first parameter is modified and returned as the result.