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| fprintf |
| Portability: | ISO/ANSI C conforming, UNIX compatible |
| SYNOPSIS | |
| DESCRIPTION | |
| RETURN VALUE | |
| DIAGNOSTICS | |
| PORTABILITY | |
| IMPLEMENTATION | |
| EXAMPLE | |
| RELATED FUNCTIONS | |
| SEE ALSO |
| SYNOPSIS |
#include <stdio.h> int fprintf(FILE *f, const char *format, var1, var2, ...);
| DESCRIPTION |
fprintf
writes output to the stream associated with the
FILE
object addressed by
f
under
the control of the string addressed by
format
. The argument list following
format
may contain one or more additional arguments whose values are to be formatted
and transmitted.
format
points to a string
that contains ordinary characters (not including
%
) that are sent without modification to the file and 0 or more conversion
specifications. Conversion specifications begin with the
%
character. The
%
character may be followed by these specifications:
hh, h, l,
ll, j, z, t,
or L
d, i,
o, u, x, X, f,
e, E, g, G, c,
s, n, p, or V
that specifies the conversion to be performed.
-
|
left-justifies the result of the conversion within the field. |
+
|
always precedes the result of a signed conversion with a plus sign or minus sign. |
space
|
precedes the result of a signed conversion
with a space or a minus sign. (If both
space
and
+
are used, the
space
flag is ignored.) |
#
|
uses an alternate form of the conversion.
This flag affects the
o
and
x
(or
X
) integer-conversion specifiers
and all of the floating-point conversion specifiers.
For
For
|
0
|
for
d
,
i
,
o
,
u
,
x
,
X
,
e
,
E
,
f
,
g
, and
G
conversions, leading
0
s are used
to pad the field width. (If both
-
and
0
are used, the
0
flag is ignored.)
For
|
| @ |
for conversions that specify or dereference
a pointer (p, s, n, V), treat pointers as
_ _far. |
The field width specifies the minimum number of characters
in the converted value. If the value has fewer characters than that specified
by the field width, it is padded on the left (or right, if the
-
flag is used). By default, the pad character is a blank.
The precision specifies the minimum number of
digits
to appear for the
d
,
i
,
o
,
u
,
p
,
x,
and
X
conversions. For the
e
,
E,
and
f
conversions, the precision specifies the number
of digits to appear after the decimal indicator. For the
g
and
G
conversions, the precision
specifies the maximum number of significant digits to appear. Finally, the
precision specifies the maximum number of characters to be used in the
s
conversion.
An
*
may be used
for either the field width, the precision, or both. If used, the value of
the field width or precision is supplied by an
int
argument. This argument appears in the argument list before the
argument to be converted. A negative value for the field width is taken as
a
-
(left-justify) flag followed by a positive
field width. A negative value for the precision is ignored.
An
h
before a
d
,
i
,
o
,
u
,
x
, or
X
conversion
specifier indicates that the conversion applies to a
short int
or
unsigned short int
.
An
h
before an
n
conversion specifier indicates that the conversion applies to a pointer
to a
short int
.
An
l
, z, or t before a
d
,
i
,
o
,
u
,
x
, or
X
conversion specifier indicates
that the conversion applies to a
long int
or an
unsigned long int
. An
l
before an
n
conversion specifier
indicates that the conversion applies to a pointer to a
long int
. An
L
before an
e
,
E
,
f
,
g
, or
G
conversion specifier indicates that the conversion
applies to a
long double
.
The type of conversion to be performed is specified by one of these characters:
c
|
converts the corresponding
int
argument to
unsigned char
and writes the character. |
d
,
i
|
converts the corresponding
int
argument to decimal notation. |
e
,
E
|
converts the corresponding
double
argument to the form
[-] d.ddde± dd
or
[-] d.dddE±
dd
. The precision has the same effect as with the
f
conversion. The exponent always has two digits. |
f
|
converts the corresponding
double
argument to the form
[-] ddd.ddd
. The precision indicates the number of digits after the
decimal indicator. If no precision is given, the default is 6. If the precision
is given as 0, a decimal indicator is not used. If a decimal indicator is
used, at least one digit appears before it. |
g
,
G
|
converts the
double
argument using the
f
or
e
(or
E
) format.
The precision specifies the number of significant digits in the converted
result. An
e
conversion is used if the
exponent is greater than the precision or is less than -3. Unless the
#
(alternate form) flag is used, trailing 0s
are removed. The decimal indicator appears only if followed by a digit. |
n
|
writes a number into the string addressed
by the corresponding
int *
argument. The
number written is the number of characters written to the output stream so
far by this call to
fprintf
. |
o
|
converts the corresponding
unsigned int
argument to octal notation. |
p
|
converts the
void *
argument to a sequence of printable characters. In this implementation,
p
is converted as if
x
were
specified. |
s
|
writes characters from the string
addressed by the corresponding
char *
argument until a terminating null character ('\0') is encountered or the number
of characters specified by the precision have been copied. The null character,
if encountered, is not written. |
u
|
converts the corresponding
unsigned int
argument to decimal notation. |
V
|
is the same as the
%s
conversion specifier, except that it expects the corresponding argument
to be a pointer to a PL/I or Pascal format varying-length character string.
See the
SAS/C Compiler Interlanguage Communication Feature User's Guide for more information on this conversion specifier. |
x
,
X
|
converts the corresponding
unsigned int
argument to hexadecimal notation.
The letters abcdef are used for
x
conversion
and ABCDEF for
X
conversion. |
A
%
character can
be written by using the sequence
%%
in
the format string. The
fprintf
formats
are described in more detail in the ISO/ANSI C standard.
In support of installations that use terminals with
only uppercase characters, this implementation of
fprintf
accepts any of the lowercase format characters in uppercase.
Use of this extension renders a program nonportable.
| RETURN VALUE |
fprintf
returns the number of characters transmitted to the output file.
| DIAGNOSTICS |
If there is an error during output,
fprintf
returns a negative value.
| PORTABILITY |
The
%V
format is an extension and is not portable.
| IMPLEMENTATION |
The format string can also contain multibyte
characters. For details on how
fprintf
handles multibyte characters in the format string and in conversions, see
Chapter 11, "Multibyte Character Functions," in the
SAS/C Library Reference, Volume 2.
fprintf
can only
produce up to 512 characters per conversion specification, except for %s and
%V conversions, which are limited to 16 megabytes.
| EXAMPLE |
#include <math.h>
#include <stdio.h>
include <stdlib.h>
main()
{
int i;
double x;
FILE *sysout;
/* Print a columnar table of logs and square roots to an */
/* MVS SYSOUT data set. */
sysout = fopen("dsn:sysout=a", "w");
if (!sysout) abort();
fprintf(sysout, " x %10s log(x) %10s sqrt(x)\n\n", " ", " ");
/* Print heading. */ for(i = 1; i < = 20; ++i)
for(i = 1; i <= 20; ++i0 {
x = i;
fprintf(sysout, "%3d%10s%10.5f%10s%10.5f\n",
i, " ", log(x), " ", sqrt(x));
}
exit(EXIT_SUCCESS);
}
| RELATED FUNCTIONS |
fscanf
,
printf
,
sprintf
,
vfprintf
| SEE ALSO |
|
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Copyright © 2001 by SAS Institute Inc., Cary, NC, USA. All rights reserved.