fprintf

fprintf( 
p_port 
t_formatString 
[ g_arg1 ... ] 
) 
=> t

Description

Writes formatted output to a port.

The fprintf function writes formatted output to the port given as the first argument. The optional arguments following the format string are printed according to their corresponding format specifications.

printf is identical to fprintf except that it does not take the p_port argument and the output is written to poport.

Output is right justified within a field by default unless an optional minus sign “-” immediately follows the % character, which will then be left justified. To print a percent sign, you must use two percent signs in succession. You must explicitly put \n in your format string to print a newline character and \t for a tab.

Common Output Format Specifications

Format Specification	Type(s) of Argument	Prints
%d	fixnum	Integer in decimal radix
%o	fixnum	Integer in octal
%x	fixnum	Integer in hexadecimal
%f	flonum	Floating-point number in the style [-]ddd.ddd
%e	flonum	Floating-point number in the style [-]d.ddde[-]ddd
%g	flonum	Floating-point number in style f or e, whichever gives full precision in minimum space Qualifying %g with width may cause imprecise results to be printed.
%s	string, symbol	Prints out a string (without quotes) or the print name of a symbol
%c	string, symbol	The first character
%n	fixnum, flonum	Number
%P	list	Point
%B	list	Box
%N	any	Prints an object in the old style, that is, does not call the printself function
%L	list	Default format for the data type Print behavior depends on the value of the printpretty variable: If printpretty is nil, this behaves like %N If printpretty is non-nil (default), %L uses printself for standard objects
%A	any	Prints any type of object using the printself representation

The t_formatString argument is a conversion control string containing directives listed in the table above. The %L, %P, and %B directives ignore the width and precision fields.

%[-][width][.precision]conversion_code 
    [-]              = left justify 
    [width]          = minimum number of character positions 
    [.precision]     = number of characters to be printed 
    conversion_code 

Arguments

p_port	Output port to write to.
t_formatString	Characters to be printed verbatim, intermixed with format specifications prefixed by the % sign.
g_arg1	The arguments following the format string are printed according to their corresponding format specifications.

Value Returned

t	Prints the formatted output and returns t.

Examples

p = outfile("power.out")
=> port:"power.out"

for(i 0 15 fprintf(p "%20d %-20d\n" 2**i 3**i))
=> t

close( p)

At this point the power.out file has the following contents.

The following example shows the use of %A, which calls the printself method.

defmethod(printself ((obj fixnum))

sprintf(nil "FIXNUM{%d}" obj));;Defines the printself method

printf("Print control A returns: %A\n" 42);; %A calls the printself method

=> Print control A returns: FIXNUM{42}

The following example shows the use of %L, which calls printself only for standard objects.

defmethod(printself ((obj fixnum))

sprintf(nil "FIXNUM{%d}" obj));;Defines the printself method

printf("Print control L returns: %L\n" 42)

=> Print control L returns: 42

The following example shows the use of %L, %A, and %N print controls with printf when printing standard objects. %A prints the same result as %L and %N does not call the printself method.

defclass(A () ());; Defines a class A

defmethod(printself ((obj A));; Defines the printself method

sprintf(nil "OBJ_A{%L}" obj))

printf("Print control L returns: %L\n" Instance('A))

printf("Print control A returns: %A\n" Instance('A))

printf("Print control N returns: %N\n" Instance('A))

=> Print control L returns: OBJ_A{stdobj@0x83bf024}

Print control A returns: OBJ_A{stdobj@0x83bf024}

Print control N returns: stdobj@0x83bf03c

Related Topics

close

fscanf, scanf, sscanf

outfile

printf

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