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.\" Copyright (c) 1989, 1990, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\" Copyright (c) 1997-2005
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.\" Herbert Xu <herbert@gondor.apana.org.au>. All rights reserved.
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.\" This code is derived from software contributed to Berkeley by
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.\" the Institute of Electrical and Electronics Engineers, Inc.
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" from: @(#)printf.1 8.1 (Berkeley) 6/6/93
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formats and prints its arguments, after the first, under control
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is a character string which contains three types of objects: plain characters,
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which are simply copied to standard output, character escape sequences which
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are converted and copied to the standard output, and format specifications,
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each of which causes printing of the next successive
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after the first are treated as strings if the corresponding format is
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otherwise it is evaluated as a C constant, with the following extensions:
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.Bl -bullet -offset indent -compact
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A leading plus or minus sign is allowed.
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If the leading character is a single or double quote, the value is the
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code of the next character.
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The format string is reused as often as necessary to satisfy the
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Any extra format specifications are evaluated with zero or the null
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Character escape sequences are in backslash notation as defined in
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The characters and their meanings are as follows:
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.Bl -tag -width Ds -offset indent
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Write an \*[Lt]escape\*[Gt] character.
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Write a \*[Lt]bell\*[Gt] character.
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Write a \*[Lt]backspace\*[Gt] character.
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Write a \*[Lt]form-feed\*[Gt] character.
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Write a \*[Lt]new-line\*[Gt] character.
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Write a \*[Lt]carriage return\*[Gt] character.
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Write a \*[Lt]tab\*[Gt] character.
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Write a \*[Lt]vertical tab\*[Gt] character.
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Write a \*[Lt]single quote\*[Gt] character.
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Write a \*[Lt]double quote\*[Gt] character.
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Write a backslash character.
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Write an 8\-bit character whose
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value is the 1\-, 2\-, or 3\-digit octal number
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Write an 8\-bit character whose
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value is the 1\- or 2\-digit hexadecimal number
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Each format specification is introduced by the percent character
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The remainder of the format specification includes,
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in the following order:
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.It "Zero or more of the following flags:"
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specifying that the value should be printed in an ``alternative form''.
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formats, this option has no effect.
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format the precision of the number is increased to force the first
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character of the output string to a zero.
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format, a non-zero result has the string
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formats, the result will always contain a decimal point, even if no
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digits follow the point (normally, a decimal point only appears in the
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results of those formats if a digit follows the decimal point).
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formats, trailing zeros are not removed from the result as they
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.\" I turned this off - decided it isn't a valid use of '#'
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.\" format, backslash-escape sequences are expanded first;
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A minus sign `\-' which specifies
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of the output in the indicated field;
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A `+' character specifying that there should always be
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a sign placed before the number when using signed formats.
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A space specifying that a blank should be left before a positive number
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A `+' overrides a space if both are used;
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A zero `0' character indicating that zero-padding should be used
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rather than blank-padding.
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A `\-' overrides a `0' if both are used;
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An optional digit string specifying a
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if the output string has fewer characters than the field width it will
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be blank-padded on the left (or right, if the left-adjustment indicator
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has been given) to make up the field width (note that a leading zero
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is a flag, but an embedded zero is part of a field width);
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followed by an optional digit string giving a
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which specifies the number of digits to appear after the decimal point,
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formats, or the maximum number of characters to be printed
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formats); if the digit string is missing, the precision is treated
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A character which indicates the type of format to use (one of
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.Cm diouxXfwEgGbBcs ) .
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A field width or precision may be
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instead of a digit string.
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supplies the field width or precision.
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The format characters and their meanings are:
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is printed as a signed decimal (d or i), unsigned octal, unsigned decimal,
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or unsigned hexadecimal (X or x), respectively.
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is printed in the style
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.Pf [\-]ddd Cm \&. No ddd
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where the number of d's
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after the decimal point is equal to the precision specification for
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If the precision is missing, 6 digits are given; if the precision
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is explicitly 0, no digits and no decimal point are printed.
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is printed in the style
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.Pf [\-]d Cm \&. No ddd Cm e No \\*(Pmdd
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is one digit before the decimal point and the number after is equal to
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the precision specification for the argument; when the precision is
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missing, 6 digits are produced.
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An upper-case E is used for an `E' format.
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whichever gives full precision in minimum space.
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Characters from the string
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are printed with backslash-escape sequences expanded.
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The following additional backslash-escape sequences are supported:
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to ignore any remaining characters in the string operand containing it,
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any remaining string operands, and any additional characters in
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Write an 8\-bit character whose
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value is the 1\-, 2\-, or 3\-digit
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Write the control character
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Generates characters `\e000' through `\e037`, and `\e177' (from `\e^?').
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with the 8th bit set.
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Generates characters `\e241' through `\e376`.
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Write the control character
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with the 8th bit set.
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Generates characters `\e000' through `\e037`, and `\e177' (from `\eM^?').
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Characters from the string
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are printed with unprintable characters backslash-escaped using the
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.Pf ` Cm \e Ar c No ',
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.Pf ` Cm \e^ Ar c No ',
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.Pf ` Cm \eM\- Ar c No '
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.Pf ` Cm \eM^ Ar c No ',
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formats described above.
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The first character of
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Characters from the string
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are printed until the end is reached or until the number of characters
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indicated by the precision specification is reached; if the
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precision is omitted, all characters in the string are printed.
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Print a `%'; no argument is used.
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In no case does a non-existent or small field width cause truncation of
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a field; padding takes place only if the specified field width exceeds
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exits 0 on success, 1 on failure.
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Support for the floating point formats and `*' as a field width and precision
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are optional in POSIX.
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The behaviour of the %B format and the \e', \e", \exxx, \ee and
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\e[M][\-|^]c escape sequences are undefined in POSIX.
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Since the floating point numbers are translated from
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to floating-point and
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then back again, floating-point precision may be lost.
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Hexadecimal character constants are restricted to, and should be specified
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as, two character constants. This is contrary to the ISO C standard but
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does guarantee detection of the end of the constant.
added
removed
dash/bltin/printf.1
