Variable sized padding in printf

by

Yes, if you use * in your format string, it gets a number from the arguments:

printf ("%0*d\n", 3, 5);

will print “005”.

Keep in mind you can only pad with spaces or zeros. If you want to pad with something else, you can use something like:

#include <stdio.h>
#include <string.h>
int main (void) {
    char *s = "MyText";
    unsigned int sz = 9;
    char *pad = "########################################";
    printf ("%.*s%s\n", (sz < strlen(s)) ? 0 : sz - strlen(s), pad, s);
}

This outputs ###MyText when sz is 9, or MyText when sz is 2 (no padding but no truncation). You may want to add a check for pad being too short.

More Related Contents:

  1. How to format a number using comma as thousands separator in C?
  2. string format for intptr_t and uintptr_t
  3. Left-pad printf with spaces
  4. Function does not return printf
  5. Please explain the difference in the printfs below
  6. decimal of numbers in c
  7. Why does printf not flush after the call unless a newline is in the format string?
  8. Printing leading 0’s in C
  9. printf format specifiers for uint32_t and size_t
  10. printf adds extra `FFFFFF` to hex print from a char array [duplicate]
  11. call printf using va_list
  12. What is the argument for printf that formats a long?
  13. Behaviour of printf when printing a %d without supplying variable name
  14. How to printf “unsigned long” in C?
  15. Why is printf with a single argument (without conversion specifiers) deprecated?
  16. Determining sprintf buffer size – what’s the standard?
  17. using printf to print out floating values
  18. Centering strings with printf()
  19. Passing too many arguments to printf
  20. printf with “%d” of numbers starting with 0 (ex “0102”) giving unexpected answer (ex ‘”66″)
  21. What is the conversion specifier for printf that formats a long?
  22. Wrong format specifiers in scanf (or) printf
  23. What primitive data type is time_t? [duplicate]
  24. Does C have a string type? [closed]
  25. Is it possible to print out only a certain section of a C-string, without making a separate substring?
  26. Printf long long int in C with GCC?
  27. cross-platform printing of 64-bit integers with printf
  28. What precisely does the %g printf specifier mean?
  29. C dynamically printf double, no loss of precision and no trailing zeroes
  30. What is the difference between %f and %lf in C?

Leave a Comment