A recreation of parts of the printf function, including correct behaviour for undefined situations.

It matches the output exactly for all combinations of the following implementations:

After writing a '%' sign, the following specifiers are supported:

• 'c' - A single character.
• 's' - A string.
• 'p' - A pointer (as a hexadecimal address).
• 'd' - An integer in decimal format.
• 'i' - An integer in decimal format.
• 'u' - An unsigned integer in decimal format.
• 'x' - An unsigned integer in hexadecimal format with lowercase letters.
• 'X' - An unsigned integer in hexadecimal format with uppercase letters.
• '%' - To just print a percent sign.

Additionally, the following flags can be added in any order between the '%' and the specifier:

• '#' - Prepend "0x"/"0X" for x/X specifier, respectively.
• '+' - Always print the sign for signed integers. Overrides a space flag.
• ' ' - If no plus flag is given, print a space in front of signed integers.
• '-' - Left-justify. Overrides a 0 flag.
• '0' - Instead of spaces, pad the value with zeros.

Following the flags, a width can be given:

• number, or '*' - The minimum number of characters to be printed.
  • If the conversion prints less, the rest will be printed as padding with spaces to the left of the value by default. This can be adjusted with the flags.

After or instead of width, a precision can be given:

• '.', followed by a number, or '*' - The minimum number of digits to be printed for number conversions, or the maximum number of characters to be printed from a string.
  • Just a dot is taken as a precision of 0.

For both width and precision, a '*' can be placed instead so the value will be taken from the next argument.