code snippets

Awk Snippet for Extracting XML Messages with a Given ID from a Log File

03/27/2015 by Luc

I recently had occasion to extract XML messages with a specific id from log files, resulting in the following gnarly awk snippet. The sed statement at the end is for stripping out some unwanted debug statements. There must be a better way to do this, let me know in the comments (except don’t, because they are disabled, because apparently only spammers read this blog).

#$1 id tag (e.g. if the identifier is specified with <id>1234</id>, use id)
#$2 id (e.g. if the identifier is enclosed with <id>1234</id>, use id)
#$3 message separator (e.g. </message>)
#$4 file prefix (e.g. if there are multiple messages in the file with the same id, use this prefix when writing out the resulting files)
#$5 log file (the name of the file to read)
extract_message(){
	awk -v var="<${1}>${2}<\\\/${1}>"  \
		-v ORS="</${3}>\n" \
		-v RS="<\\\/${3}>"  \
		'$0 ~ var {print}' $5 | sed 's/^[0-9][0-9].*DEBUG.*</</' \
		| awk -v pre="${4}" '{print $0 > pre NR}' RS='\\n\\n' -	
}

#$1 id tag (e.g. if the identifier is specified with <id>1234</id>, use id)

#$2 id (e.g. if the identifier is enclosed with <id>1234</id>, use id)

#$3 message separator (e.g. </message>)

#$4 file prefix (e.g. if there are multiple messages in the file with the same id, use this prefix when writing out the resulting files)

#$5 log file (the name of the file to read)

extract_message(){

awk -v var="<${1}>${2}<\\\/${1}>" \

-v ORS="</${3}>\n" \

-v RS="<\\\/${3}>" \

'$0 ~ var {print}' $5 | sed 's/^[0-9][0-9].*DEBUG.*</</' \

| awk -v pre="${4}" '{print $0 > pre NR}' RS='\\n\\n' -

}

Java Collections Quick Reference

03/21/2015 by Luc

A cheat sheet for my frequently used/forgotten Java Collections snippets.

Quickly Create a List

import static java.util.Arrays.asList;
asList("hello", "goodbye");
import static java.util.Collections.unmodifiableList;
unmodifiableList(asList("hello", "goodbye"));

import static java.util.Arrays.asList;

asList("hello", "goodbye");

import static java.util.Collections.unmodifiableList;

unmodifiableList(asList("hello", "goodbye"));

Empty Collection Syntax

List<String> requiredInputs = Collections.<String>emptyList();

1	List<String> requiredInputs = Collections.<String>emptyList();

Also see here.

Safe Empty Array

public static String[] safe(String[] other ) {
    return other == null ? new String[0] : other;
}

public static String[] safe(String[] other ) {

return other == null ? new String[0] : other;

}

Convert Array to List

Arrays.asList(values)

1	Arrays.asList(values)

Collection to Array

values.toArray(new String[values.size()])

1	values.toArray(new String[values.size()])

Loop Over Keys And Values In A Map

for (Iterator<Map.Entry<String, Object>> it = resultsData.entrySet().iterator(); it.hasNext();) {
            Map.Entry<String, Object> entry = it.next();
            String key = entry.getKey();
            Object value = entry.getValue();
            System.out.println(String.format("key: %s, value: %s", key, value));
        }

for (Iterator<Map.Entry<String, Object>> it = resultsData.entrySet().iterator(); it.hasNext();) {

Map.Entry<String, Object> entry = it.next();

String key = entry.getKey();

Object value = entry.getValue();

System.out.println(String.format("key: %s, value: %s", key, value));

}

Convert a Collection to Another Type With Commons Collections

06/19/2013 by Luc

private Collection<Apple> convert(final Collection<Orange> values) {
    final Collection<Apple> converted = CollectionUtils.collect(values, new Transformer(){
      public Object transform(final Object target){
        Orange result = null;
        if(target != null){
            result = new Apple(target.getName());
        }
        return result;
      }
    });
    return converted;
}

private Collection<Apple> convert(final Collection<Orange> values) {

final Collection<Apple> converted = CollectionUtils.collect(values, new Transformer(){

public Object transform(final Object target){

Orange result = null;

if(target != null){

result = new Apple(target.getName());

}

return result;

}

});

return converted;

}

How To Select Elements From a Collection With Apache Commons Collections

06/18/2013 by Luc

private List<Vegetable> getVegetablesLike(List<Vegetable> allVegetables, 
                final Vegetable vegetable) {
    return (List<Vegetable>) 
        select(allVegetables, new Predicate() {
        @Override
        public boolean evaluate(Object o) {
            Vegetable other = (Vegetable) o;
            return other.equals(vegetable);
        }
    });
}

private List<Vegetable> getVegetablesLike(List<Vegetable> allVegetables,

final Vegetable vegetable) {

return (List<Vegetable>)

select(allVegetables, new Predicate() {

@Override

public boolean evaluate(Object o) {

Vegetable other = (Vegetable) o;

return other.equals(vegetable);

}

});

}

Script to Update WordPress Secret Keys in Every wp-config.php

05/05/2013 by Luc

#!/bin/bash
find . -name wp-config.php -print | while read line
do 
	curl http://api.wordpress.org/secret-key/1.1/salt/ > wp_keys.txt
	sed -i.bak -e '/put your unique phrase here/d' -e '/AUTH_KEY/d' -e '/SECURE_AUTH_KEY/d' -e '/LOGGED_IN_KEY/d' -e '/NONCE_KEY/d' -e '/AUTH_SALT/d' -e '/SECURE_AUTH_SALT/d' -e '/LOGGED_IN_SALT/d' -e '/NONCE_SALT/d' $line
	cat wp_keys.txt >> $line
	rm wp_keys.txt
done

#!/bin/bash

find . -name wp-config.php -print | while read line

curl http://api.wordpress.org/secret-key/1.1/salt/ > wp_keys.txt

sed -i.bak -e '/put your unique phrase here/d' -e '/AUTH_KEY/d' -e '/SECURE_AUTH_KEY/d' -e '/LOGGED_IN_KEY/d' -e '/NONCE_KEY/d' -e '/AUTH_SALT/d' -e '/SECURE_AUTH_SALT/d' -e '/LOGGED_IN_SALT/d' -e '/NONCE_SALT/d' $line

cat wp_keys.txt >> $line

rm wp_keys.txt

done