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Printf, Returns, Example – Zilog ZUSBOPTS User Manual

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Standard Functions

UM017105-0511

430

Zilog Developer Studio II – ZNEO™
User Manual

Returns

The value of x raised to the power y.

Example

double x=2.0;

double y=3.0;

double res;

res=pow(x,y);

printf

Writes output to the stream pointed to by stdout, under control of the string pointed to by
format that specifies how subsequent arguments are converted for output.

A format string contains two types of objects: plain characters, which are copied
unchanged to stdout, and conversion specifications, each of which fetch zero or more sub-
sequent arguments. The results are undefined if there are insufficient arguments for the
format. If the format is exhausted while arguments remain, the excess arguments are eval-
uated but otherwise ignored. The

printf

function returns when the end of the format

string is encountered.

Each conversion specification is introduced by the character “

%

”. After this

%

character,

the following events occur in sequence:

1. Zero or more flags that modify the meaning of the conversion specification.

2. An optional decimal integer specifying a minimum field width. If the converted value

has fewer characters than the field width, it is padded on the left (or right, if the left
adjustment flag, described later, has been given) to the field width. The padding is
with spaces unless the field width integer starts with a zero, in which case the padding
is with zeros.

3. An optional precision that gives the minimum number of digits to appear for the d, i,

o, u, x, and X conversions, the number of digits to appear after the decimal point for e,
E, and f conversions, the maximum number of significant digits for the g and G con-
versions, or the maximum number of characters to be written from a string in s con-
version. The precision takes the form of a period (.) followed by an optional decimal
integer; if the integer is omitted, it is treated as zero. The amount of padding specified
by the precision overrides that specified by the field width.

4. An optional h specifies that a following d, i, o, u, x, or X conversion character applies

to a

short_int

or

unsigned_short_int

argument (the argument has been pro-

moted according to the integral promotions, and its value is converted to

short_int

or

unsigned_short_int

before printing). An optional l (ell) specifies that a follow-

ing d, i, o, u, x or X conversion character applies to a

long_int

or

unsigned_long_int

argument. An optional L specifies that a following e, E, f, g, or

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