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PRINTF(1)		  BSD General Commands Manual		     PRINTF(1)

     printf -- formatted output

     printf format [arguments ...]

     The printf	utility	formats	and prints its arguments, after	the first, un-
     der control of the	format.	 The format is a character string which	con-
     tains three types of objects: plain characters, which are simply copied
     to	standard output, character escape sequences which are converted	and
     copied to the standard output, and	format specifications, each of which
     causes printing of	the next successive argument.

     The arguments after the first are treated as strings if the corresponding
     format is either c, b or s; otherwise it is evaluated as a	C constant,
     with the following	extensions:

	   o   A leading plus or minus sign is allowed.
	   o   If the leading character	is a single or double quote, the value
	       is the ASCII code of the	next character.

     The format	string is reused as often as necessary to satisfy the
     arguments.	 Any extra format specifications are evaluated with zero or
     the null string.

     Character escape sequences	are in backslash notation as defined in	the
     ANSI X3.159-1989 ("ANSI C89"), with extensions.  The characters and their
     meanings are as follows:

	   \a	   Write a <bell> character.
	   \b	   Write a <backspace> character.
	   \c	   Ignore remaining characters in this string.
	   \f	   Write a <form-feed> character.
	   \n	   Write a <new-line> character.
	   \r	   Write a <carriage return> character.
	   \t	   Write a <tab> character.
	   \v	   Write a <vertical tab> character.
	   \'	   Write a <single quote> character.
	   \\	   Write a backslash character.
	   \0num   Write an 8-bit character whose ASCII	value is the 1-, 2-,
		   or 3-digit octal number num.

     Each format specification is introduced by	the percent character (``%'').
     The remainder of the format specification includes, in the	following or-

     Zero or more of the following flags:

	     #	     A `#' character specifying	that the value should be
		     printed in	an ``alternate form''.	For c, d, and s, for-
		     mats, this	option has no effect.  For the o formats the
		     precision of the number is	increased to force the first
		     character of the output string to a zero.	For the	x (X)
		     format, a non-zero	result has the string 0x (0X)
		     prepended to it.  For e, E, f, g, and G, formats, the re-
		     sult will always contain a	decimal	point, even if no dig-
		     its follow	the point (normally, a decimal point only ap-
		     pears in the results of those formats if a	digit follows
		     the decimal point).  For g	and G formats, trailing	zeros
		     are not removed from the result as	they would otherwise

	     -	     A minus sign `-' which specifies left adjustment of the
		     output in the indicated field;

	     +	     A `+' character specifying	that there should always be a
		     sign placed before	the number when	using signed formats.

	     ` '     A space specifying	that a blank should be left before a
		     positive number for a signed format.  A `+' overrides a
		     space if both are used;

	     0	     A zero `0'	character indicating that zero-padding should
		     be	used rather than blank-padding.	 A `-' overrides a `0'
		     if	both are used;

     Field Width:
	     An	optional digit string specifying a field width;	if the output
	     string has	fewer characters than the field	width it will be
	     blank-padded on the left (or right, if the	left-adjustment	indi-
	     cator has been given) to make up the field	width (note that a
	     leading zero is a flag, but an embedded zero is part of a field

	     An	optional period, `.', followed by an optional digit string
	     giving a precision	which specifies	the number of digits to	appear
	     after the decimal point, for e and	f formats, or the maximum num-
	     ber of characters to be printed from a string; if the digit
	     string is missing,	the precision is treated as zero;

	     A character which indicates the type of format to use (one	of
	     diouxXfFeEgGaAcsb).  The uppercase	formats	differ from their low-
	     ercase counterparts only in that the output of the	former is en-
	     tirely in uppercase.

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

     The format	characters and their meanings are:

     diouXx	 The argument is printed as a signed decimal (d	or i), un-
		 signed	octal, unsigned	decimal, or unsigned hexadecimal (X or
		 x), respectively.

     fF		 The argument is printed in the	style `[-]ddd.ddd' where the
		 number	of d's after the decimal point is equal	to the preci-
		 sion 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.	 The values
		 infinity and NaN are printed as `inf' and `nan', respec-

     eE		 The argument is printed in the	style e	`[-d.ddd+-dd]' where
		 there is one digit before the decimal point and the number
		 after is equal	to the precision specification for the argu-
		 ment; when the	precision is missing, 6	digits are produced.
		 The values infinity and NaN are printed as `inf' and `nan',

     gG		 The argument is printed in style f (F)	or in style e (E)
		 whichever gives full precision	in minimum space.

     aA		 The argument is printed in style `[-h.hhh+-pd]' where there
		 is one	digit before the hexadecimal point and the number af-
		 ter is	equal to the precision specification for the argument;
		 when the precision is missing,	enough digits are produced to
		 convey	the argument's exact double-precision floating-point
		 representation.  The values infinity and NaN are printed as
		 `inf' and `nan', respectively.

     c		 The first character of	argument is printed.

     s		 Characters from the string argument are printed until the end
		 is reached or until the number	of characters indicated	by the
		 precision specification is reached; however if	the precision
		 is 0 or missing, all characters in the	string are printed.

     b		 As for	s, but interpret character escapes in backslash	nota-
		 tion in the string argument.

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

     The decimal point character is defined in the program's locale (category

     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.

     The printf	utility	exits 0	on success, and	>0 if an error occurs.

     The traditional BSD behavior of converting	arguments of numeric formats
     not beginning with	a digit	to the ASCII code of the first character is
     not supported.

     echo(1), printf(3)

     The printf	command	is expected to be compatible with the IEEE Std 1003.2
     ("POSIX.2") specification.

     The printf	command	appeared in 4.3BSD-Reno.  It is	modeled	after the
     standard library function,	printf(3).

     Since the floating	point numbers are translated from ASCII	to floating-
     point and then back again,	floating-point precision may be	lost.

     ANSI hexadecimal character	constants were deliberately not	provided.

     The escape	sequence \000 is the string terminator.	 When present in the
     format, the format	will be	truncated at the \000 character.

     Multibyte characters are not recognized in	format strings (this is	only a
     problem if	`%' can	appear inside a	multibyte character).

BSD				 July 3, 2004				   BSD


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