org.unix4j.unix.grep.GrepOptions Maven / Gradle / Ivy
package org.unix4j.unix.grep;
import java.util.Collections;
import java.util.Iterator;
import org.unix4j.convert.OptionSetConverters.OptionSetConverter;
import org.unix4j.convert.ValueConverter;
import org.unix4j.option.DefaultOptionSet;
import org.unix4j.option.Option;
import org.unix4j.option.OptionSet;
import org.unix4j.unix.Grep;
import org.unix4j.unix.grep.GrepOption;
/**
* Interface implemented by all option sets for the {@link Grep grep} command.
* It is recommended to use {@link Grep#Options} to specify a valid
* combination of options.
*
* The options for the grep command are:
*
*
* {@code -i} {@code --ignoreCase} Match lines ignoring the case when comparing the strings, also known
from Unix with its acronym 'i'. {@code -v} {@code --invertMatch} Invert the match result, that is, a non-matching line is written to
the output and a matching line is not. This option is also known
from Unix with its acronym 'v'. {@code -F} {@code --fixedStrings} Use fixed-strings matching instead of regular expressions. This is
usually faster than the standard regexp version.
(This option is ignored if a {@code pattern} operand is specified
instead of the {@code regexp} string).
{@code -n} {@code --lineNumber} Prefix each line of output with the line number within its input
file. {@code -c} {@code --count} Suppress normal output; instead print a count of matching lines for
each input file. With the {@code -v}, {@code --invertMatch} option,
count non-matching lines. {@code -l} {@code --matchingFiles} Suppress normal output; instead print the name of each input file
from which output would normally have been printed. The scanning
will stop on the first match. {@code -x} {@code --wholeLine} Select only those matches that exactly match the whole line
excluding the terminating line ending.
(This option is ignored if a {@code pattern} operand is specified
instead of the {@code regexp} string).
*
* This interface serves as an alias for the extended interface to simplify the
* command signature methods by avoiding generic parameters.
*/
public interface GrepOptions extends OptionSet {
/**
* Constant for an empty option set.
*/
GrepOptions EMPTY = new GrepOptions() {
@Override
public Class optionType() {
return GrepOption.class;
}
@Override
public boolean isSet(GrepOption option) {
return false;
}
/**
* Returns 0 as this is a set with no active options.
*
* @return zero
*/
@Override
public int size() {
return 0;
}
/**
* Returns an immutable empty set.
*
* @return an immutable empty set.
*/
@Override
public java.util.Set asSet() {
return Collections.emptySet();
}
/**
* Returns an iterator returning no elements.
*
* @return an immutable iterator with no elements.
*/
@Override
public Iterator iterator() {
return asSet().iterator();
}
/**
* Returns true if the {@link Option#acronym() acronym} should be used
* for the specified {@code option} in string representations.
*
* This method returns always true;
*
* @param option
* the option of interest
* @return always true
*/
@Override
public boolean useAcronymFor(GrepOption option) {
return true;
}
};
/**
* Default implementation for a modifiable option set.
*/
class Default extends DefaultOptionSet implements GrepOptions {
/**
* Default constructor for an empty option set with no active options.
*/
public Default() {
super(GrepOption.class);
}
/**
* Constructor for an option set with a single active option.
* @param option the option to be set
*/
public Default(GrepOption option) {
super(option);
}
/**
* Constructor for an option set with the given active options.
* @param options the options to be set
*/
public Default(GrepOption... options) {
this();
setAll(options);
}
/**
* Constructor for an option set initialized with the options given by
* another option set.
*
* @param optionSet set with the options to be active
*/
public Default(OptionSet optionSet) {
this();
setAll(optionSet);
}
}
/**
* Value converter for {@link GrepOptions} based on an {@link OptionSetConverter}.
*/
ValueConverter CONVERTER = new ValueConverter() {
private final OptionSetConverter converter = new OptionSetConverter(GrepOption.class);
@Override
public GrepOptions convert(Object value) {
final OptionSet set = converter.convert(value);
return set == null ? null : new Default(set);
}
};
}