diff options
Diffstat (limited to 'newlib/libc/stdio/sprintf.c')
| -rw-r--r-- | newlib/libc/stdio/sprintf.c | 661 |
1 files changed, 450 insertions, 211 deletions
diff --git a/newlib/libc/stdio/sprintf.c b/newlib/libc/stdio/sprintf.c index 346749a68..d2203fb3c 100644 --- a/newlib/libc/stdio/sprintf.c +++ b/newlib/libc/stdio/sprintf.c @@ -17,7 +17,7 @@ /* FUNCTION - <<printf>>, <<fprintf>>, <<asprintf>>, <<sprintf>>, <<snprintf>>---format output +<<printf>>, <<fprintf>>, <<sprintf>>, <<snprintf>>, <<asprintf>>, <<asnprintf>>---format output INDEX fprintf @@ -29,6 +29,8 @@ INDEX sprintf INDEX snprintf +INDEX + asnprintf ANSI_SYNOPSIS #include <stdio.h> @@ -36,271 +38,508 @@ ANSI_SYNOPSIS int printf(const char *<[format]> [, <[arg]>, ...]); int fprintf(FILE *<[fd]>, const char *<[format]> [, <[arg]>, ...]); int sprintf(char *<[str]>, const char *<[format]> [, <[arg]>, ...]); - int asprintf(char **<[strp]>, const char *<[format]> [, <[arg]>, ...]); int snprintf(char *<[str]>, size_t <[size]>, const char *<[format]> [, <[arg]>, ...]); - -TRAD_SYNOPSIS - #include <stdio.h> - - int printf(<[format]> [, <[arg]>, ...]) - char *<[format]>; - - int fprintf(<[fd]>, <[format]> [, <[arg]>, ...]); - FILE *<[fd]>; - char *<[format]>; - - int asprintf(<[strp]>, <[format]> [, <[arg]>, ...]); - char **<[strp]>; - char *<[format]>; - - int sprintf(<[str]>, <[format]> [, <[arg]>, ...]); - char *<[str]>; - char *<[format]>; - - int snprintf(<[str]>, size_t <[size]>, <[format]> [, <[arg]>, ...]); - char *<[str]>; - size_t <[size]>; - char *<[format]>; + int asprintf(char **<[strp]>, const char *<[format]> [, <[arg]>, ...]); + char *asnprintf(char *<[str]>, size_t *<[size]>, const char *<[format]> + [, <[arg]>, ...]); + + int _printf_r(struct _reent *<[ptr]>, const char *<[format]> + [, <[arg]>, ...]); + int _fprintf_r(struct _reent *<[ptr]>, FILE *<[fd]>, + const char *<[format]> [, <[arg]>, ...]); + int _sprintf_r(struct _reent *<[ptr]>, char *<[str]>, + const char *<[format]> [, <[arg]>, ...]); + int _snprintf_r(struct _reent *<[ptr]>, char *<[str]>, size_t <[size]>, + const char *<[format]> [, <[arg]>, ...]); + int _asprintf_r(struct _reent *<[ptr]>, char **<[strp]>, + const char *<[format]> [, <[arg]>, ...]); + char *_asnprintf_r(struct _reent *<[ptr]>, char *<[str]>, + size_t *<[size]>, const char *<[format]> + [, <[arg]>, ...]); DESCRIPTION <<printf>> accepts a series of arguments, applies to each a format specifier from <<*<[format]>>>, and writes the - formatted data to <<stdout>>, terminated with a null character. - The behavior of <<printf>> is undefined if there are not enough - arguments for the format. - <<printf>> returns when it reaches the end of the format string. - If there are more arguments than the format requires, excess - arguments are ignored. - - <<fprintf>>, <<asprintf>>, <<sprintf>> and <<snprintf>> are identical - to <<printf>>, other than the destination of the formatted output: - <<fprintf>> sends the output to a specified file <[fd]>, while - <<asprintf>> stores the output in a dynamically allocated buffer, - while <<sprintf>> stores the output in the specified char array - <[str]> and <<snprintf>> limits number of characters written to - <[str]> to at most <[size]> (including terminating <<0>>). For - <<sprintf>> and <<snprintf>>, the behavior is undefined if the - output <<*<[str]>>> overlaps with one of the arguments. For - <<asprintf>>, <[strp]> points to a pointer to char which is filled - in with the dynamically allocated buffer. <[format]> is a pointer - to a charater string containing two types of objects: ordinary - characters (other than <<%>>), which are copied unchanged to the - output, and conversion specifications, each of which is introduced - by <<%>>. (To include <<%>> in the output, use <<%%>> in the format - string.) A conversion specification has the following form: - -. %[<[flags]>][<[width]>][.<[prec]>][<[size]>][<[type]>] - - The fields of the conversion specification have the following meanings: + formatted data to <<stdout>>, without a terminating NUL + character. The behavior of <<printf>> is undefined if there + are not enough arguments for the format. <<printf>> returns + when it reaches the end of the format string. If there are + more arguments than the format requires, excess arguments are + ignored. + + <<fprintf>> is like <<printf>>, except that output is directed + to the stream <[fd]> rather than <<stdout>>. + + <<sprintf>> is like <<printf>>, except that output is directed + to the buffer <[str]>, and a terminating NUL is output. + Behavior is undefined if more output is generated than the + buffer can hold. + + <<snprintf>> is like <<sprintf>>, except that output is + limited to at most <[size]> bytes, including the terminating + <<NUL>>. As a special case, if <[size]> is 0, <[str]> can be + NULL, and <<snprintf>> merely calculates how many bytes would + be printed. + + <<asprintf>> is like <<sprintf>>, except that the output is + stored in a dynamically allocated buffer, <[pstr]>, which + should be freed later with <<free>>. + + <<asnprintf>> is like <<sprintf>>, except that the return type + is either the original <[str]> if it was large enough, or a + dynamically allocated string if the output exceeds *<[size]>; + the length of the result is returned in *<[size]>. When + dynamic allocation occurs, the contents of the original + <[str]> may have been modified. + + For <<sprintf>>, <<snprintf>>, and <<asnprintf>>, the behavior + is undefined if the output <<*<[str]>>> overlaps with one of + the arguments. Behavior is also undefined if the argument for + <<%n>> within <<*<[format]>>> overlaps another argument. + + <[format]> is a pointer to a character string containing two + types of objects: ordinary characters (other than <<%>>), + which are copied unchanged to the output, and conversion + specifications, each of which is introduced by <<%>>. (To + include <<%>> in the output, use <<%%>> in the format string.) + A conversion specification has the following form: + +. %[<[pos]>][<[flags]>][<[width]>][.<[prec]>][<[size]>]<[type]> + + The fields of the conversion specification have the following + meanings: O+ + o <[pos]> + + Conversions normally consume arguments in the order that they + are presented. However, it is possible to consume arguments + out of order, and reuse an argument for more than one + conversion specification (although the behavior is undefined + if the same argument is requested with different types), by + specifying <[pos]>, which is a decimal integer followed by + '$'. The integer must be between 1 and <NL_ARGMAX> from + limits.h, and if argument <<%n$>> is requested, all earlier + arguments must be requested somewhere within <[format]>. If + positional parameters are used, then all conversion + specifications except for <<%%>> must specify a position. + o <[flags]> - an optional sequence of characters which control - output justification, numeric signs, decimal points, - trailing zeroes, and octal and hex prefixes. - The flag characters are minus (<<->>), plus (<<+>>), - space ( ), zero (<<0>>), and sharp (<<#>>). They can - appear in any combination. - - o+ - o - - The result of the conversion is left justified, and the right is - padded with blanks. If you do not use this flag, the result is right - justified, and padded on the left. - - o + - The result of a signed conversion (as determined by <[type]>) - will always begin with a plus or minus sign. (If you do not use - this flag, positive values do not begin with a plus sign.) - - o " " (space) - If the first character of a signed conversion specification - is not a sign, or if a signed conversion results in no - characters, the result will begin with a space. If the - space ( ) flag and the plus (<<+>>) flag both appear, - the space flag is ignored. - - o 0 - If the <[type]> character is <<d>>, <<i>>, <<o>>, <<u>>, - <<x>>, <<X>>, <<e>>, <<E>>, <<f>>, <<g>>, or <<G>>: leading zeroes, - are used to pad the field width (following any indication of sign or - base); no spaces are used for padding. If the zero (<<0>>) and - minus (<<->>) flags both appear, the zero (<<0>>) flag will - be ignored. For <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, and <<X>> - conversions, if a precision <[prec]> is specified, the zero (<<0>>) - flag is ignored. - - Note that <<0>> is interpreted as a flag, not as the beginning - of a field width. - - o # - The result is to be converted to an alternative form, according - to the next character: - - o+ - o 0 - increases precision to force the first digit - of the result to be a zero. + <[flags]> is an optional sequence of characters which control + output justification, numeric signs, decimal points, trailing + zeros, and octal and hex prefixes. The flag characters are + minus (<<->>), plus (<<+>>), space ( ), zero (<<0>>), sharp + (<<#>>), and quote (<<'>>). They can appear in any + combination, although not all flags can be used for all + conversion specification types. + + o+ + o ' + Since newlib only supports the C locale, this + flag has no effect in this implementation. + But in other locales, when <[type]> is <<i>>, + <<d>>, <<u>>, <<f>>, <<F>>, <<g>>, or <<G>>, + the locale-dependent thousand's separator is + inserted prior to zero padding. + + o - + The result of the conversion is left + justified, and the right is padded with + blanks. If you do not use this flag, the + result is right justified, and padded on the + left. + + o + + The result of a signed conversion (as + determined by <[type]> of <<d>>, <<i>>, <<a>>, + <<A>>, <<e>>, <<E>>, <<f>>, <<F>>, <<g>>, or + <<G>>) will always begin with a plus or minus + sign. (If you do not use this flag, positive + values do not begin with a plus sign.) + + o " " (space) + If the first character of a signed conversion + specification is not a sign, or if a signed + conversion results in no characters, the + result will begin with a space. If the space + ( ) flag and the plus (<<+>>) flag both + appear, the space flag is ignored. + + o 0 + If the <[type]> character is <<d>>, <<i>>, + <<o>>, <<u>>, <<x>>, <<X>>, <<a>>, <<A>>, + <<e>>, <<E>>, <<f>>, <<g>>, or <<G>>: leading + zeros are used to pad the field width + (following any indication of sign or base); no + spaces are used for padding. If the zero + (<<0>>) and minus (<<->>) flags both appear, + the zero (<<0>>) flag will be ignored. For + <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, and <<X>> + conversions, if a precision <[prec]> is + specified, the zero (<<0>>) flag is ignored. + + Note that <<0>> is interpreted as a flag, not + as the beginning of a field width. + + o # + The result is to be converted to an + alternative form, according to the <[type]> + character: + + o+ + o o + Increases precision to force the first + digit of the result to be a zero. o x - a non-zero result will have a <<0x>> prefix. + A non-zero result will have a <<0x>> + prefix. o X - a non-zero result will have a <<0X>> prefix. + A non-zero result will have a <<0X>> + prefix. - o e, E or f - The result will always contain a decimal point - even if no digits follow the point. - (Normally, a decimal point appears only if a - digit follows it.) Trailing zeroes are removed. + o a, A, e, E, f, or F + The result will always contain a + decimal point even if no digits follow + the point. (Normally, a decimal point + appears only if a digit follows it.) + Trailing zeros are removed. o g or G - same as <<e>> or <<E>>, but trailing zeroes - are not removed. + The result will always contain a + decimal point even if no digits follow + the point. Trailing zeros are not + removed. o all others - undefined. + Undefined. o- - o- - - o <[width]> - - <[width]> is an optional minimum field width. You can either - specify it directly as a decimal integer, or indirectly by - using instead an asterisk (<<*>>), in which case an <<int>> - argument is used as the field width. Negative field widths - are not supported; if you attempt to specify a negative field - width, it is interpreted as a minus (<<->>) flag followed by a - positive field width. - - o <[prec]> - - an optional field; if present, it is introduced with `<<.>>' - (a period). This field gives the maximum number of - characters to print in a conversion; the minimum number of - digits of an integer to print, for conversions with <[type]> - <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, and <<X>>; the maximum number of - significant digits, for the <<g>> and <<G>> conversions; - or the number of digits to print after the decimal - point, for <<e>>, <<E>>, and <<f>> conversions. You can specify - the precision either directly as a decimal integer or - indirectly by using an asterisk (<<*>>), in which case - an <<int>> argument is used as the precision. Supplying a negative - precision is equivalent to omitting the precision. - If only a period is specified the precision is zero. - If a precision appears with any other conversion <[type]> - than those listed here, the behavior is undefined. - - o <[size]> - - <<h>>, <<l>>, and <<L>> are optional size characters which - override the default way that <<printf>> interprets the - data type of the corresponding argument. <<h>> forces - the following <<d>>, <<i>>, <<o>>, <<u>>, <<x>> or <<X>> conversion - <[type]> to apply to a <<short>> or <<unsigned short>>. <<h>> also - forces a following <<n>> <[type]> to apply to - a pointer to a <<short>>. Similarily, an - <<l>> forces the following <<d>>, <<i>>, <<o>>, <<u>>, - <<x>> or <<X>> conversion <[type]> to apply to a <<long>> or - <<unsigned long>>. <<l>> also forces a following <<n>> <[type]> to - apply to a pointer to a <<long>>. <<l>> with <<c>>, <<s>> is - equivalent to <<C>>, <<S>> respectively. If an <<h>> - or an <<l>> appears with another conversion - specifier, the behavior is undefined. <<L>> forces a - following <<e>>, <<E>>, <<f>>, <<g>> or <<G>> conversion <[type]> to - apply to a <<long double>> argument. If <<L>> appears with - any other conversion <[type]>, the behavior is undefined. - - o <[type]> - - <[type]> specifies what kind of conversion <<printf>> performs. - Here is a table of these: - - o+ + o- + + o <[width]> + + <[width]> is an optional minimum field width. You can + either specify it directly as a decimal integer, or + indirectly by using instead an asterisk (<<*>>), in + which case an <<int>> argument is used as the field + width. If positional arguments are used, then the + width must also be specified positionally as <<*m$>>, + with m as a decimal integer. Negative field widths + are treated as specifying the minus (<<->>) flag for + left justfication, along with a positive field width. + The resulting format may be wider than the specified + width. + + o <[prec]> + + <[prec]> is an optional field; if present, it is + introduced with `<<.>>' (a period). You can specify + the precision either directly as a decimal integer or + indirectly by using an asterisk (<<*>>), in which case + an <<int>> argument is used as the precision. If + positional arguments are used, then the precision must + also be specified positionally as <<*m$>>, with m as a + decimal integer. Supplying a negative precision is + equivalent to omitting the precision. If only a + period is specified the precision is zero. The effect + depends on the conversion <[type]>. + + o+ + o d, i, o, u, x, or X + Minimum number of digits to appear. If no + precision is given, defaults to 1. + + o a or A + Number of digits to appear after the decimal + point. If no precision is given, the + precision defaults to the minimum needed for + an exact representation. + + o e, E, f or F + Number of digits to appear after the decimal + point. If no precision is given, the + precision defaults to 6. + + o g or G + Maximum number of significant digits. A + precision of 0 is treated the same as a + precision of 1. If no precision is given, the + precision defaults to 6. + + o s or S + Maximum number of characters to print from the + string. If no precision is given, the entire + string is printed. + + o all others + undefined. + + o- + + o <[size]> + + <[size]> is an optional modifier that changes the data + type that the corresponding argument has. Behavior is + unspecified if a size is given that does not match the + <[type]>. + + o+ + o hh + With <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, or + <<X>>, specifies that the argument should be + converted to a <<signed char>> or <<unsigned + char>> before printing. + + With <<n>>, specifies that the argument is a + pointer to a <<signed char>>. + + o h + With <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, or + <<X>>, specifies that the argument should be + converted to a <<short>> or <<unsigned short>> + before printing. + + With <<n>>, specifies that the argument is a + pointer to a <<short>>. + + o l + With <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, or + <<X>>, specifies that the argument is a + <<long>> or <<unsigned long>>. + + With <<c>>, specifies that the argument has + type <<wint_t>>. + + With <<s>>, specifies that the argument is a + pointer to <<wchar_t>>. + + With <<n>>, specifies that the argument is a + pointer to a <<long>>. + + With <<a>>, <<A>>, <<e>>, <<E>>, <<f>>, <<F>>, + <<g>>, or <<G>>, has no effect (because of + vararg promotion rules, there is no need to + distinguish between <<float>> and <<double>>). + + o ll + With <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, or + <<X>>, specifies that the argument is a + <<long long>> or <<unsigned long long>>. + + With <<n>>, specifies that the argument is a + pointer to a <<long long>>. + + o j + With <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, or + <<X>>, specifies that the argument is an + <<intmax_t>> or <<uintmax_t>>. + + With <<n>>, specifies that the argument is a + pointer to an <<intmax_t>>. + + o z + With <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, or + <<X>>, specifies that the argument is a + <<ssize_t>> or <<size_t>>. + + With <<n>>, specifies that the argument is a + pointer to a <<ssize_t>>. + + o t + With <<d>>, <<i>>, <<o>>, <<u>>, <<x>>, or + <<X>>, specifies that the argument is a + <<ptrdiff_t>>. + + With <<n>>, specifies that the argument is a + pointer to a <<ptrdiff_t>>. + + o L + With <<a>>, <<A>>, <<e>>, <<E>>, <<f>>, <<F>>, + <<g>>, or <<G>>, specifies that the argument + is a <<long double>>. + + o- + + o <[type]> + + <[type]> specifies what kind of conversion <<printf>> + performs. Here is a table of these: + + o+ o % - prints the percent character (<<%>>) + Prints the percent character (<<%>>). o c - prints <[arg]> as single character - + Prints <[arg]> as single character. If the + <<l>> size specifier is in effect, a multibyte + character is printed. + o C - prints wchar_t <[arg]> as single multibyte character - + Short for <<%lc>>. + o s - prints characters until precision is reached or a null terminator - is encountered; takes a string pointer + Prints the elements of a pointer to <<char>> + until the precision or a null character is + reached. If the <<l>> size specifier is in + effect, the pointer is to an array of + <<wchar_t>>, and the string is converted to + multibyte characters before printing. o S - converts wchar_t characters to multibyte output characters until - precision is reached or a null wchar_t terminator - is encountered; takes a wchar_t pointer + Short for <<%ls>>. - o d - prints a signed decimal integer; takes an <<int>> (same as <<i>>) + o d or i + Prints a signed decimal integer; takes an + <<int>>. Leading zeros are inserted as + necessary to reach the precision. A precision + of 0 produces an empty string. - o i - prints a signed decimal integer; takes an <<int>> (same as <<d>>) + o D + Newlib extension, short for <<%ld>>. o o - prints a signed octal integer; takes an <<int>> + Prints an unsigned octal integer; takes an + <<unsigned>>. Leading zeros are inserted as + necessary to reach the precision. A precision + of 0 produces an empty string. + + o O + Newlib extension, short for <<%lo>>. o u - prints an unsigned decimal integer; takes an <<int>> + Prints an unsigned decimal integer; takes an + <<unsigned>>. Leading zeros are inserted as + necessary to reach the precision. A precision + of 0 produces an empty string. + + o U + Newlib extension, short for <<%lu>>. o x - prints an unsigned hexadecimal integer (using <<abcdef>> as - digits beyond <<9>>); takes an <<int>> + Prints an unsigned hexadecimal integer (using + <<abcdef>> as digits beyond <<9>>); takes an + <<unsigned>>. Leading zeros are inserted as + necessary to reach the precision. A precision + of 0 produces an empty string. o X - prints an unsigned hexadecimal integer (using <<ABCDEF>> as - digits beyond <<9>>); takes an <<int>> + Like <<x>>, but uses <<ABCDEF>> as digits + beyond <<9>>. o f - prints a signed value of the form <<[-]9999.9999>>; takes - a floating-point number - + Prints a signed value of the form + <<[-]9999.9999>>, with the precision + determining how many digits follow the decimal + point; takes a <<double>> (remember that + <<float>> promotes to <<double>> as a vararg). + The low order digit is rounded to even. If + the precision results in at most DECIMAL_DIG + digits, the result is rounded correctly; if + more than DECIMAL_DIG digits are printed, the + result is only guaranteed to round back to the + original value. + + If the value is infinite, the result is + <<inf>>, and no zero padding is performed. If + the value is not a number, the result is + <<nan>>, and no zero padding is performed. + + o F + Like <<f>>, but uses <<INF>> and <<NAN>> for + non-finite numbers. + o e - prints a signed value of the form <<[-]9.9999e[+|-]999>>; takes a - floating-point number + Prints a signed value of the form + <<[-]9.9999e[+|-]999>>; takes a <<double>>. + The digit before the decimal point is non-zero + if the value is non-zero. The precision + determines how many digits appear between + <<.>> and <<e>>, and the exponent always + contains at least two digits. The value zero + has an exponent of zero. If the value is not + finite, it is printed like <<f>>. o E - prints the same way as <<e>>, but using <<E>> to introduce the - exponent; takes a floating-point number + Like <<e>>, but using <<E>> to introduce the + exponent, and like <<F>> for non-finite + values. o g - prints a signed value in either <<f>> or <<e>> form, based on given - value and precision---trailing zeros and the decimal point are - printed only if necessary; takes a floating-point number - + Prints a signed value in either <<f>> or <<e>> + form, based on the given value and + precision---an exponent less than -4 or + greater than the precision selects the <<e>> + form. Trailing zeros and the decimal point + are printed only if necessary; takes a + <<double>>. + o G - prints the same way as <<g>>, but using <<E>> for the exponent if an - exponent is needed; takes a floating-point number + Like <<g>>, except use <<F>> or <<E>> form. + + o a + Prints a signed value of the form + <<[-]0x1.ffffp[+|-]9>>; takes a <<double>>. + The letters <<abcdef>> are used for digits + beyond <<9>>. The precision determines how + many digits appear after the decimal point. + The exponent contains at least one digit, and + is a decimal value representing the power of + 2; a value of 0 has an exponent of 0. + Non-finite values are printed like <<f>>. + + o A + Like <<a>>, except uses <<X>>, <<P>>, and + <<ABCDEF>> instead of lower case. o n - stores (in the same object) a count of the characters written; - takes a pointer to <<int>> + Takes a pointer to <<int>>, and stores a count + of the number of bytes written so far. No + output is created. o p - prints a pointer in an implementation-defined format. - This implementation treats the pointer as an - <<unsigned long>> (same as <<Lu>>). - o- -O- + Takes a pointer to <<void>>, and prints it in + an implementation-defined format. This + implementation is similar to <<%#tx>>), except + that <<0x>> appears even for the NULL pointer. + + o- + O- + <<_printf_r>>, <<_fprintf_r>>, <<_asprintf_r>>, + <<_sprintf_r>>, <<_snprintf_r>>, <<_asnprintf_r>> are simply + reentrant versions of the functions above. RETURNS -<<sprintf>> and <<asprintf>> return the number of bytes in the output string, -save that the concluding <<NULL>> is not counted. -<<printf>> and <<fprintf>> return the number of characters transmitted. -If an error occurs, <<printf>> and <<fprintf>> return <<EOF>> and -<<asprintf>> returns -1. No error returns occur for <<sprintf>>. +On success, <<sprintf>> and <<asprintf>> return the number of bytes in +the output string, except the concluding <<NUL>> is not counted. +<<snprintf>> returns the number of bytes that would be in the output +string, except the concluding <<NUL>> is not counted. <<printf>> and +<<fprintf>> return the number of characters transmitted. +<<asnprintf>> returns the original <[str]> if there was enough room, +otherwise it returns an allocated string. + +If an error occurs, the result of <<printf>>, <<fprintf>>, +<<snprintf>>, and <<asprintf>> is a negative value, and the result of +<<asnprintf>> is NULL. No error returns occur for <<sprintf>>. For +<<printf>> and <<fprintf>>, <<errno>> may be set according to +<<fputc>>. For <<asprintf>> and <<asnprintf>>, <<errno>> may be set +to ENOMEM if allocation fails, and for <<snprintf>>, <<errno>> may be +set to EOVERFLOW if <[size]> or the output length exceeds INT_MAX. PORTABILITY - The ANSI C standard specifies that implementations must - support at least formatted output of up to 509 characters. +ANSI C requires <<printf>>, <<fprintf>>, <<sprintf>>, and +<<snprintf>>. <<asprintf>> and <<asnprintf>> are newlib extensions. + +The ANSI C standard specifies that implementations must support at +least formatted output of up to 509 characters. This implementation +has no inherent limit. + +Depending on how newlib was configured, not all format specifiers are +supported. Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>, <<lseek>>, <<read>>, <<sbrk>>, <<write>>. |