Package io.jawk.jrt

Class AwkPrintf

java.lang.Object

io.jawk.jrt.AwkPrintf

public final class AwkPrintf
extends Object

AWK's printf/sprintf formatting engine.

This class implements the POSIX AWK formatting semantics (as implemented by gawk), which differ from both C's printf() and String.format(String, Object...) in several ways:

• %s converts numeric values to strings with AWK's number-to-string rules: integral values are printed without a fractional part, and other values are formatted with CONVFMT;
• %c prints the character for a numeric code point, or the first character of a string value;
• %i is an alias for %d, and %u prints the value as an unsigned 64-bit integer;
• dynamic field width and precision (*) consume arguments, and gawk-style positional specifiers (%n$) are honored;
• integer conversions of values that exceed the 64-bit range fall back to the full decimal expansion (%d/%i) or %g notation (%u/%o/%x/%X), like gawk;
• NaN and infinities print as nan, inf, and -inf;
• %e, %f, and %g round halfway cases to even, like the C library used by gawk;
• unknown conversion specifiers are printed verbatim without consuming an argument, and a fatal AwkRuntimeException is raised when there are not enough arguments to satisfy the format string.

This formatting logic was originally externalized in the Printf4J project, which emulated glibc's printf(). It has been reincorporated into Jawk and adapted to AWK's semantics.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DEFAULT_CONVFMT	Default AWK number-to-string conversion format (CONVFMT).

Method Summary

Modifier and Type	Method	Description
static String	sprintf(String format, Object... args)	Formats the given arguments with AWK's sprintf() semantics, using Locale.US and the default CONVFMT ("%.6g").
static String	sprintf(Locale locale, String convfmt, String format, Object... args)	Formats the given arguments with AWK's sprintf() semantics.
static String	toAwkString(Object value, String conversionFormat, Locale locale)	Converts a value to a string using AWK's number-to-string rules.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_CONVFMT

public static final String DEFAULT_CONVFMT

Default AWK number-to-string conversion format (CONVFMT).

See Also:

• Constant Field Values

Method Details

sprintf

public static String sprintf(String format,
 Object... args)

Formats the given arguments with AWK's sprintf() semantics, using Locale.US and the default CONVFMT ("%.6g").

Parameters:

format - AWK format string

args - arguments supplied after the format string

Returns:

the formatted text

Throws:

AwkRuntimeException - when there are not enough arguments to satisfy the format string

sprintf

public static String sprintf(Locale locale,
 String convfmt,
 String format,
 Object... args)

Formats the given arguments with AWK's sprintf() semantics.

Parameters:

locale - locale used for numeric formatting (decimal separator, grouping separator for the ' flag)

convfmt - number-to-string conversion format (CONVFMT) used by %s for non-integral numeric values

format - AWK format string

args - arguments supplied after the format string

Returns:

the formatted text

Throws:

AwkRuntimeException - when there are not enough arguments to satisfy the format string

toAwkString

public static String toAwkString(Object value,
 String conversionFormat,
 Locale locale)

Converts a value to a string using AWK's number-to-string rules.

Non-numeric values are converted with toString(). Numeric values holding an integral value are printed without a fractional part (using the full decimal expansion when the value exceeds the 64-bit range), NaN and infinities print as nan, inf, and -inf, and all other numeric values are formatted with the supplied conversion format (CONVFMT or OFMT).

Parameters:

value - value to convert

conversionFormat - number-to-string conversion format

locale - locale used for numeric formatting

Returns:

the AWK string value of value