PRINTF(3S)																PRINTF(3S)

NAME

       printf, fprintf, sprintf - formatted output conversion

SYNOPSIS

       #include <stdio.h>

       printf(format [, arg ] ...  )
       char *format;

       fprintf(stream, format [, arg ] ...  )
       FILE *stream;
       char *format;

       sprintf(s, format [, arg ] ...  )
       char *s, format;

DESCRIPTION

       Printf  places  output on the standard output stream stdout.  Fprintf places output on the named output stream.	Sprintf places `output' in
       the string s, followed by the character `'.

       Each of these functions converts, formats, and prints its arguments after the first under control of the first argument.  The  first  argu-
       ment is a character string which contains two types of objects: plain characters, which are simply copied to the output stream, and conver-
       sion specifications, each of which causes conversion and printing of the next successive arg printf.

       Each conversion specification is introduced by the character %.	Following the %, there may be

       -      an optional minus sign `-' which specifies left adjustment of the converted value in the indicated field;

       -      an optional digit string specifying a field width; if the converted value has fewer characters than  the	field  width  it  will	be
	      blank-padded  on the left (or right, if the left-adjustment indicator has been given) to make up the field width; if the field width
	      begins with a zero, zero-padding will be done instead of blank-padding;

       -      an optional period `.'  which serves to separate the field width from the next digit string;

       -      an optional digit string specifying a precision which specifies the number of digits to appear after the decimal point, for  e-  and
	      f-conversion, or the maximum number of characters to be printed from a string;

       -      the  character l specifying that a following d, o, x, or u corresponds to a long integer arg.  (A capitalized conversion code accom-
	      plishes the same thing.)

       -      a character which indicates the type of conversion to be applied.

       A field width or precision may be `*' instead of a digit string.  In this case an integer arg supplies the field width or precision.

       The conversion characters and their meanings are

       dox    The integer arg is converted to decimal, octal, or hexadecimal notation respectively.

       f      The float or double arg is converted to decimal notation in the style `[-]ddd.ddd' where the number of d's after the  decimal  point
	      is  equal  to  the  precision  specification for the argument.  If the precision is missing, 6 digits are given; if the precision is
	      explicitly 0, no digits and no decimal point are printed.

       e      The float or double arg is converted in the style `[-]d.ddde+-dd' where there is one digit before the decimal point and  the  number
	      after is equal to the precision specification for the argument; when the precision is missing, 6 digits are produced.

       g      The float or double arg is printed in style d, in style f, or in style e, whichever gives full precision in minimum space.

       c      The character arg is printed.  Null characters are ignored.

       s      Arg  is taken to be a string (character pointer) and characters from the string are printed until a null character or until the num-
	      ber of characters indicated by the precision specification is reached; however if the precision is 0 or missing all characters up to
	      a null are printed.

       u      The unsigned integer arg is converted to decimal and printed (the result will be in the range 0 to 65535).

       %      Print a `%'; no argument is converted.

       In  no  case  does  a  non-existent or small field width cause truncation of a field; padding takes place only if the specified field width
       exceeds the actual width.  Characters generated by printf are printed by putc(3).

       Examples
       To print a date and time in the form `Sunday, July 3, 10:02', where weekday and month are pointers to null-terminated strings:

	      printf("%s, %s %d, %02d:%02d", weekday, month, day, hour, min);

       To print pi to 5 decimals:

	      printf("pi = %.5f", 4*atan(1.0));

SEE ALSO

       putc(3), scanf(3), ecvt(3)

BUGS

       Very wide fields (>128 characters) fail.

																	PRINTF(3S)