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

NAME
     printf -- formatted output

SYNOPSIS
     printf format [arguments ...]

DESCRIPTION
     Printf formats and	prints its arguments, after the	first, under control
     of	the format.  The format	is a character string which contains 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	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, or	not a
	       digit, plus, or minus sign, 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").  The characters and	their meanings are as
     follows:

	   \a	   Write a <bell> character.
	   \b	   Write a <backspace> character.
	   \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.
	   \num	   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-
     der:

     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
		     be;

	     -	     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
	     width);

     Precision:
	     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;

     Format:
	     A character which indicates the type of format to use (one	of
	     diouxXfwEgGcs).

     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.

     f		 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.

     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.
		 An upper-case E is used for an	`E' format.

     gG		 The argument is printed in style f or in style	e (E) which-
		 ever gives full precision in minimum space.

     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.

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

     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.

     Some shells may provide a builtin printf command which is similar or
     identical to this utility.	 Consult the builtin(1)	manual page.

RETURN VALUES
     Printf exits 0 on success,	1 on failure.

SEE ALSO
     builtin(1), csh(1), sh(1),	printf(3)

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

BUGS
     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.

BSD				 June 6, 1993				   BSD

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | SEE ALSO | HISTORY | BUGS

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