HP-UX Reference (11i v1 05/09) - 3 Library Functions N-Z (vol 7)

p
printf(3S) printf(3S)
A field width or precision can be indicated by an asterisk instead of a digit string. In this case, an integer
arg supplies the field width or precision. The arg that is actually converted is not fetched until the conver-
sion letter is seen, so the args specifying field width, or precision, or both must appear in that order before
the arg, if any, to be converted. A negative field width is taken as a
- flag followed by a positive field
width. A negative precision is taken as if the precision were omitted. Format strings containing
%n$
conversion specifications can also indicate a field width or precision by the sequence
*n$. The n indicates
the position of an integer arg . With the
*n$ sequence, the args specifying field width or precision can
appear before or after the arg to be converted.
The flag characters and their meanings are:
’ The integer portion of the result of a decimal conversion (%i, %d, %u, %f, %g, or %G) will
be formatted with thousands’ grouping characters. Thousands’ grouping and the separator
character are determined by the "grouping" and "thousands_sep" fields of the
LC_NUMERIC category respectively. (See localedef(4)). For other conversions the behavior
is undefined. The nonmonetary grouping character is used.
- The resulting conversion is left-justified within the field.
+ The resulting signed conversion always begins with a sign (+ or -).
blank If the first character of a signed conversion is not a sign, a blank is prefixed to the result.
This implies that if the blank and
+ flags both appear, the blank flag is ignored.
# This flag specifies that the value is converted to an ‘‘alternate form’’. For
c, d, i, s, n, and
u conversions, the flag has no effect. For o conversion, it increases the precision to force
the first digit of the result to be a zero. For x or X
conversion, a nonzero result is prefixed
by
0x or 0X.Forap conversion, a nonzero result is prefixed by
0x.Fore, E, f, g, and G
conversions, the result always contains a radix character, even if no digits follow the radix.
(Normally, a radix character appears in the resulting conversions only if followed by a
digit). For
g and G conversions, trailing zeros are not removed from the result (which they
normally are).
0 Leading zeros (following any indication of sign or base) are used to pad to the field width for
all conversion characters. No space padding is performed. If both the 0 and - appear, the
0 flag is ignored. For d, i, o, u,
p, x, and X, conversions, if a precision is specified, the 0
flag is ignored.
The conversion characters and their meanings are:
d,i,o,u,x,X The integer arg is converted to signed decimal (
d and i are identical), unsigned octal
(
o), decimal (u), or hexadecimal notation (x and X), respectively; the letters
abcdef
are used for x conversion and the letters ABCDEF for X conversion. The precision
specifies the minimum number of digits to appear. If the value being converted can be
represented in fewer digits, it is expanded with leading zeros. (For compatibility with
older versions, padding with leading zeros can alternatively be specified by inserting a
zero in front of the field width. This does not imply an octal value for the field width).
The default precision is 1. The result of converting a zero value with a precision of
zero is a null string.
f The double arg is converted to decimal notation in the style [-]dddrddd, where r is
the radix character. The number of digits after the radix character is equal to the pre-
cision specification. If the precision is missing, six digits are output. If the precision
is explicitly zero, no radix character appears.
e,E The double arg is converted in the style [-]drddde±ddd, where r is the radix char-
acter. There is one digit before the radix character and the number of digits after it is
equal to the precision; when the precision is missing, six digits are produced; if the
precision is zero, no radix character appears. The E format code produces a number
with E instead of e introducing the exponent. The exponent always contains at least
two digits.
g,G The double arg is printed in style f or e (or in style E in the case of a G format code),
with the precision specifying the number of significant digits. The style used depends
on the value converted: style e is used only if the exponent resulting from the conver-
sion is less than -4 or greater than or equal to the precision. Trailing zeros are
removed from the fractional part of the result; a radix character appears only if it is
followed by a digit.
HP-UX 11i Version 1: September 2005 − 2 − Hewlett-Packard Company Section 3−−663