361 lines
11 KiB
C
361 lines
11 KiB
C
/*
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms are permitted
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* provided that the above copyright notice and this paragraph are
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* duplicated in all such forms and that any documentation,
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* advertising materials, and other materials related to such
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* distribution and use acknowledge that the software was developed
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* by the University of California, Berkeley. The name of the
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* University may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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*/
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/*
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FUNCTION
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<<printf>>, <<fprintf>>, <<sprintf>>, <<snprintf>>---format output
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INDEX
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fprintf
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INDEX
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printf
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INDEX
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sprintf
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INDEX
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snprintf
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ANSI_SYNOPSIS
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#include <stdio.h>
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int printf(const char *<[format]> [, <[arg]>, ...]);
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int fprintf(FILE *<[fd]>, const char *<[format]> [, <[arg]>, ...]);
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int sprintf(char *<[str]>, const char *<[format]> [, <[arg]>, ...]);
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int snprintf(char *<[str]>, size_t <[size]>, const char *<[format]> [, <[arg]>, ...]);
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TRAD_SYNOPSIS
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#include <stdio.h>
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int printf(<[format]> [, <[arg]>, ...])
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char *<[format]>;
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int fprintf(<[fd]>, <[format]> [, <[arg]>, ...]);
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FILE *<[fd]>;
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char *<[format]>;
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int sprintf(<[str]>, <[format]> [, <[arg]>, ...]);
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char *<[str]>;
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char *<[format]>;
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int snprintf(<[str]>, size_t <[size]>, <[format]> [, <[arg]>, ...]);
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char *<[str]>;
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size_t <[size]>;
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char *<[format]>;
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DESCRIPTION
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<<printf>> accepts a series of arguments, applies to each a
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format specifier from <<*<[format]>>>, and writes the
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formatted data to <<stdout>>, terminated with a null character.
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The behavior of <<printf>> is undefined if there are not enough
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arguments for the format.
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<<printf>> returns when it reaches the end of the format string.
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If there are more arguments than the format requires, excess
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arguments are ignored.
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<<fprintf>>, <<sprintf>> and <<snprintf>> are identical to <<printf>>,
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other than the destination of the formatted output: <<fprintf>> sends
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the output to a specified file <[fd]>, while <<sprintf>> stores the
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output in the specified char array <[str]> and <<snprintf>> limits
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number of characters written to <[str]> to at most <[size]> (including
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terminating <<0>>). For <<sprintf>> and <<snprintf>>, the behavior is
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also undefined if the output <<*<[str]>>> overlaps with one of the
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arguments. <[format]> is a pointer to a charater string containing
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two types of objects: ordinary characters (other than <<%>>), which
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are copied unchanged to the output, and conversion
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specifications, each of which is introduced by <<%>>.
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(To include <<%>> in the output, use <<%%>> in the format string.)
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A conversion specification has the following form:
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. %[<[flags]>][<[width]>][.<[prec]>][<[size]>][<[type]>]
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The fields of the conversion specification have the following meanings:
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O+
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o <[flags]>
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an optional sequence of characters which control
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output justification, numeric signs, decimal points,
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trailing zeroes, and octal and hex prefixes.
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The flag characters are minus (<<->>), plus (<<+>>),
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space ( ), zero (<<0>>), and sharp (<<#>>). They can
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appear in any combination.
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o+
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o -
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The result of the conversion is left justified, and the right is
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padded with blanks. If you do not use this flag, the result is right
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justified, and padded on the left.
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o +
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The result of a signed conversion (as determined by <[type]>)
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will always begin with a plus or minus sign. (If you do not use
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this flag, positive values do not begin with a plus sign.)
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o " " (space)
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If the first character of a signed conversion specification
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is not a sign, or if a signed conversion results in no
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characters, the result will begin with a space. If the
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space ( ) flag and the plus (<<+>>) flag both appear,
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the space flag is ignored.
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o 0
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If the <[type]> character is <<d>>, <<i>>, <<o>>, <<u>>,
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<<x>>, <<X>>, <<e>>, <<E>>, <<f>>, <<g>>, or <<G>>: leading zeroes,
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are used to pad the field width (following any indication of sign or
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base); no spaces are used for padding. If the zero (<<0>>) and
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minus (<<->>) flags both appear, the zero (<<0>>) flag will
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be ignored. For <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, and <<X>>
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conversions, if a precision <[prec]> is specified, the zero (<<0>>)
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flag is ignored.
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Note that <<0>> is interpreted as a flag, not as the beginning
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of a field width.
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o #
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The result is to be converted to an alternative form, according
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to the next character:
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o+
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o 0
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increases precision to force the first digit
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of the result to be a zero.
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o x
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a non-zero result will have a <<0x>> prefix.
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o X
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a non-zero result will have a <<0X>> prefix.
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o e, E or f
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The result will always contain a decimal point
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even if no digits follow the point.
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(Normally, a decimal point appears only if a
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digit follows it.) Trailing zeroes are removed.
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o g or G
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same as <<e>> or <<E>>, but trailing zeroes
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are not removed.
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o all others
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undefined.
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o-
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o-
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o <[width]>
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<[width]> is an optional minimum field width. You can either
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specify it directly as a decimal integer, or indirectly by
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using instead an asterisk (<<*>>), in which case an <<int>>
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argument is used as the field width. Negative field widths
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are not supported; if you attempt to specify a negative field
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width, it is interpreted as a minus (<<->>) flag followed by a
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positive field width.
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o <[prec]>
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an optional field; if present, it is introduced with `<<.>>'
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(a period). This field gives the maximum number of
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characters to print in a conversion; the minimum number of
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digits of an integer to print, for conversions with <[type]>
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<<d>>, <<i>>, <<o>>, <<u>>, <<x>>, and <<X>>; the maximum number of
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significant digits, for the <<g>> and <<G>> conversions;
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or the number of digits to print after the decimal
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point, for <<e>>, <<E>>, and <<f>> conversions. You can specify
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the precision either directly as a decimal integer or
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indirectly by using an asterisk (<<*>>), in which case
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an <<int>> argument is used as the precision. Supplying a negative
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precision is equivalent to omitting the precision.
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If only a period is specified the precision is zero.
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If a precision appears with any other conversion <[type]>
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than those listed here, the behavior is undefined.
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o <[size]>
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<<h>>, <<l>>, and <<L>> are optional size characters which
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override the default way that <<printf>> interprets the
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data type of the corresponding argument. <<h>> forces
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the following <<d>>, <<i>>, <<o>>, <<u>>, <<x>> or <<X>> conversion
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<[type]> to apply to a <<short>> or <<unsigned short>>. <<h>> also
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forces a following <<n>> <[type]> to apply to
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a pointer to a <<short>>. Similarily, an
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<<l>> forces the following <<d>>, <<i>>, <<o>>, <<u>>,
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<<x>> or <<X>> conversion <[type]> to apply to a <<long>> or
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<<unsigned long>>. <<l>> also forces a following <<n>> <[type]> to
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apply to a pointer to a <<long>>. If an <<h>>
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or an <<l>> appears with another conversion
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specifier, the behavior is undefined. <<L>> forces a
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following <<e>>, <<E>>, <<f>>, <<g>> or <<G>> conversion <[type]> to
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apply to a <<long double>> argument. If <<L>> appears with
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any other conversion <[type]>, the behavior is undefined.
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o <[type]>
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<[type]> specifies what kind of conversion <<printf>> performs.
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Here is a table of these:
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o+
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o %
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prints the percent character (<<%>>)
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o c
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prints <[arg]> as single character
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o s
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prints characters until precision is reached or a null terminator
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is encountered; takes a string pointer
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o d
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prints a signed decimal integer; takes an <<int>> (same as <<i>>)
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o i
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prints a signed decimal integer; takes an <<int>> (same as <<d>>)
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o o
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prints a signed octal integer; takes an <<int>>
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o u
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prints an unsigned decimal integer; takes an <<int>>
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o x
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prints an unsigned hexadecimal integer (using <<abcdef>> as
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digits beyond <<9>>); takes an <<int>>
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o X
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prints an unsigned hexadecimal integer (using <<ABCDEF>> as
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digits beyond <<9>>); takes an <<int>>
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o f
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prints a signed value of the form <<[-]9999.9999>>; takes
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a floating point number
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o e
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prints a signed value of the form <<[-]9.9999e[+|-]999>>; takes a
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floating point number
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o E
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prints the same way as <<e>>, but using <<E>> to introduce the
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exponent; takes a floating point number
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o g
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prints a signed value in either <<f>> or <<e>> form, based on given
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value and precision---trailing zeros and the decimal point are
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printed only if necessary; takes a floating point number
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o G
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prints the same way as <<g>>, but using <<E>> for the exponent if an
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exponent is needed; takes a floating point number
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o n
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stores (in the same object) a count of the characters written;
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takes a pointer to <<int>>
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o p
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prints a pointer in an implementation-defined format.
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This implementation treats the pointer as an
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<<unsigned long>> (same as <<Lu>>).
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o-
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O-
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RETURNS
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<<sprintf>> returns the number of bytes in the output string,
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save that the concluding <<NULL>> is not counted.
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<<printf>> and <<fprintf>> return the number of characters transmitted.
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If an error occurs, <<printf>> and <<fprintf>> return <<EOF>>. No
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error returns occur for <<sprintf>>.
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PORTABILITY
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The ANSI C standard specifies that implementations must
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support at least formatted output of up to 509 characters.
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Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
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<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
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*/
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#include <stdio.h>
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#ifdef _HAVE_STDC
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#include <stdarg.h>
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#else
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#include <varargs.h>
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#endif
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#include <limits.h>
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#include <_ansi.h>
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#include "local.h"
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int
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#ifdef _HAVE_STDC
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_DEFUN (_sprintf_r, (ptr, str, fmt), struct _reent *ptr _AND char *str _AND _CONST char *fmt _DOTS)
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#else
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_sprintf_r (ptr, str, fmt, va_alist)
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struct _reent *ptr;
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char *str;
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_CONST char *fmt;
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va_dcl
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#endif
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{
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int ret;
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va_list ap;
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FILE f;
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f._flags = __SWR | __SSTR;
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f._bf._base = f._p = (unsigned char *) str;
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f._bf._size = f._w = INT_MAX;
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f._data = ptr;
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#ifdef _HAVE_STDC
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va_start (ap, fmt);
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#else
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va_start (ap);
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#endif
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ret = vfprintf (&f, fmt, ap);
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va_end (ap);
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*f._p = 0;
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return (ret);
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}
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#ifndef _REENT_ONLY
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int
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#ifdef _HAVE_STDC
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_DEFUN (sprintf, (str, fmt), char *str _AND _CONST char *fmt _DOTS)
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#else
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sprintf (str, fmt, va_alist)
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char *str;
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_CONST char *fmt;
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va_dcl
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#endif
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{
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int ret;
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va_list ap;
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FILE f;
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f._flags = __SWR | __SSTR;
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f._bf._base = f._p = (unsigned char *) str;
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f._bf._size = f._w = INT_MAX;
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f._data = _REENT;
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#ifdef _HAVE_STDC
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va_start (ap, fmt);
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#else
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va_start (ap);
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#endif
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ret = vfprintf (&f, fmt, ap);
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va_end (ap);
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*f._p = 0;
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return (ret);
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}
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#endif
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