Flag Specifiers

The printf() conversion flags are enabled by specifying one or more of the following characters, which may appear in any order:

'

The integer portion of the result of a decimal conversion (%i, %d, %u, %f, %g, or %G) is formatted with thousands grouping characters using the non-monetary grouping character. Some locales, including the POSIX C locale, do not provide non-monetary grouping characters for use with this flag.

-

The result of the conversion is left-justified within the field. The conversion is right-justified if this flag is not specified.

+

The result of signed conversion always begins with a sign (+ or -). If this flag is not specified, the conversion begins with a sign only when a negative value is converted.

space

If the first character of a signed conversion is not a sign or if a signed conversion results in no characters, a space is placed before the result. If the space and + flags both appear, the space flag is ignored.

#

The value is converted to an alternate form if an alternate form is defined for the selected conversion. The alternate formats for conversions are described along with the corresponding conversion.

0

For d, i, o, u, x, X, e, E, f, g, and G conversions, leading zeroes (following any indication of sign or base) are used to pad to the field width. No space padding is performed. If the 0 and - flags both appear, the 0 flag is ignored. For d, i, o, u, x and X conversions, if a precision is specified, the 0 flag is ignored. If the 0 and ' flags both appear, the grouping characters are inserted before the zero padding.