printf string, variable length item

Question

#define SIZE 9
int number=5;
char letters[SIZE]; /* this wont be null-terminated */
... 

char fmt_string[20];
sprintf(fmt_string, \"%%d %%%ds\", SIZE);
/* fmt_strin         


        

Answer 1

A somewhat unknown function is asprintf. The first parameter is a **char. This function will malloc space for the string so you don't have to do the bookkeeping. Remember to free the string when done.

char *fmt_string;

asprintf(&fmt_string, "%%d %%%ds", SIZE);
printf(fmt_string, number, letters);
free(fmt_string);

is an example of use.