Sunday, April 26, 2020
Confinamiento
El café sabe amargo en mi taza de Winnie The Pooh. Podría haberle echado más azúcar, pero quiero que esté así, amargo. Cercano a como es en realidad. Cuando te vas haciendo mayor disfrutas más las cosas amargas. Las cosas que te traen un sabor a la boca menos dulce. Parece que disfrutas más de los matices menos camuflados de la existencia. Son más reales.
El café sabe amargo, ya os lo he dicho. Podría haber elegido una taza de café "normal", pero entonces no cabría tanto. Y no quiero vivir la vida a sorbos. Y tampoco soy de pensar que solo hay una forma de hacer las cosas de manera "normal". Nunca lo he sido. Me gusta pensar que eso no es ser hacker. También podría haber sacado una taza de Star Wars, de las grandes, pero esas son de mi colección.
Me apego a recuerdos. A mis pequeñas cosas que cuando las miro con la realidad aumentada de mi mirada están llenas de historias vivas que danzan frente a mis ojos. En 3D. Con música envolvente. Son casa. Son refugio. Me gusta alejarme un poco de ellos para crear nuevos recuerdos. Solo un poco. Para volver a disfrutarlos más. Y los objetos y recuerdos que vienen conmigo son yo. Son parte de mí, fueran dulces o amargos.
El café sabe amargo, pero no es intenso. Me gusta americano. Largo de agua. Aguachirri. Como lo pido siempre cuando quiero café. Sin leche. Largo como mi jornada laboral. Largo y amargo. Largo como mi pasado. Largo, espero, como mi futuro. Para sentir la experiencia durante más tiempo. Solo un poco más. Nada dura para siempre salvo en la memoria donde el tiempo se pliega. Como en la película esa de "Origen". Un sueño dentro de otro. Recursivo como los algoritmos. No se acaba. Ni lo dulce ni lo amargo. Pero el sabor del café es amargo. Y no quiero vestirlo de algo dulcificado echando mucha azúcar. Un poco para hacerlo más llevadero, puede, pero no mucho más maquillaje. Quiero sentir las cosas como son. Que duelan si tienen que doler. Que amarguen si tienen que amargar.
Mis ojos ya no son lo que eran. Están más cansaditos. Empiezan a pedir tregua de tanta lectura. De tantas letras en pantallas. De tantos mensajes que releí. De tantas y tantas hojas luchando contra mis párpados. De mi cerebro ávido por captar más de todo lo que se ve y lo que no se ve. De tantas luces en aventuras galácticas. Series de superhéroes. O de zombies que decoran el paisaje o antihéroes que van a acabar mal porque toman malas decisiones constantemente intentando avanzar. O porque la serie ya comenzó en un psiquiátrico como declaración de intenciones de lo que nos esperaba por delante.
Mis ojos ya no son lo que eran. Me piden ayuda. Mis ojos. Y se la doy a dosis pequeñas. No quiero que se acomoden. Aún no. Quiero que peleen por descifrar el mundo con sus propias herramientas. Pero de vez en cuando los consuelo. Les echo un poco de azúcar. Dejo que se acunen sobre el cristal de unas lupas de lectura. Para que aguanten más. Para que me descifren el mundo unos minutos más antes de caer rendido en la negrura de la noche.
El día es gris. Igual que ayer. Igual que el otro domingo que hizo buen día. Lo veo desde aquí. Mi sitio es el mismo que llevo ocupando durante este último mes y algo. Un rincón de la existencia con una ventana por la que veo solo un poquito del mundo analógico cuando mi foco se relaja. Solo una esquina de la vida. Por la que miro mientras me amargo mi paladar con el sabor del café. Con las gafas puestas para leer esa presentación con números y letras pequeñitas. Es mi vida. Casi enteramente mi vida es esto ahora.
El día es grande. O será que yo me siento pequeño. Como seguro que te sientes tú. Porque es como si me escondiera. Me siento un poco azul. No. No lo tomes mal. No me disgusta el color. Ni el gris ni el azul. La vida no es solo sol. La vida no es solo color amarillo. No solo luz. El azul es bonito también. Me gusta su olor. Su tacto. Y acurrucarme un rato con una de mis muchas bolitas azules. Esas que tengo en la estantería. Cojo una un rato. Me abrazo a ella. Retozo en mi sofá acurrucándola. O mirando al cielo con mi taza de Winnie The Pooh.
Mi cerebro vuela. Por el cielo. Sé que pronto saldré a jugar con las bolas amarillas. Sé que volveré a salir al parque a jugar con mis amigos. A gritar. A dar abrazos y besos. A ver un partido de fútbol. A ir a escuchar a los poetas rasgar sus guitarras. A sudar. A escuchar los gritos. A pegar los chillidos. A destrozar las canciones por no saber cantar. A mezclar el rojo con el amarillo. A mezclar el amarillo con el azul. A trepar por el monte con mi bicicleta cual motivado. A escuchar la música mientras vagabundeo en soledad por el mundo. Ese al que solo viajo yo. Por otros países. A irme a retozar con Morfeo sin tener que pelear por ello. Correr a sus brazos sin hacer cola en la frontera.
Mis palabras se amontonan. Están ahí. Guardadas. Para ti. Para las cenas. Para las charlas. Para las confesiones. Para los reencuentros. Para cuando las quieras oír. Para cuando las puedas escuchar de mi voz. Para que no sea algo digitalizado. Para que sea el sonido que emito con mis cuerdas vocales directamente. Ese que conecta directo con el motor de mi cuerpo. Ese que escribe cosas que nadie lee. Que nadie escucha. Que nadie le dicta. El inventor de los sentimientos. El pintor de las bolitas.
Mis caricias te extrañan. En los confines de mis dedos. Las noto palpitar cuando golpeo con suavidad las teclas de mi teclado. Cuando escribo algo para nadie. Pidiendo salir. Pidiendo espacio para ellas. Para que no duelan los dedos al final del día por el repiquetear constante. Para que el cansancio no sea solo mecánico sino también cuántico. Para que los dedos se muevan como olas al compás de dunas de ese desierto inmenso en soledad que queda por recorrer. Una vez más. Lentas. Eléctricas. Quemando. Como un calambre que sube por mis antebrazos y enciende el tatuaje imaginario de las llamas que nunca me hice.
La vida sigue escribiendo grietas en mi cara con tinta indeleble. En los surcos de mi piel. Donde guardo lo importante. Las risas. Los recuerdos. Los anhelos. Los planes inconclusos. Los conclusos. Con todos los metadatos. Con los recuerdos que he querido convertir en yo. En casa. Lo mejor de historia, de física y química. De arte. O incluso de filosofía sobre la vida que iba a tener pero que nunca tuve.
Mi pasado se perdió en este futuro. Porque de los mil caminos del multiverso el premio cayó en otra línea temporal. Porque la banda cambió el setlist por el camino. Porque fallé el pie de una estrofa. Porque no afinamos la canción en el mismo tempo. O porque mi diapasón se rompió por usarlo tanto a tanta velocidad. Y cada día puedo leerlos con más intensidad. Cuando me miro al espejo. Las canciones que salieron al final para el elepé son las que tengo escritas en mis arrugas. Pero aún me queda discografía que componer. Ouh, yeah!
Mis huesos me gritan. Cuando subo o bajo una escalera. Cuando recuerdo los golpes en la cadera al caerme de los patines. Cuando me levanto de la silla para preguntarle al sol qué hora es. Cuando pienso en todas las veces que necesito caerme aún. Cuando me veo volando sobre una tabla. Cuando recuerdo la negrura que viene tras la rampa. Cuando me despierto de la oscuridad y me están cosiendo la cabeza. Con sangre en los ojos. Cuando pienso en que el dolor no existe cuando el golpe es suficiente certero como para abrirte la cabeza. Y te quedas en calma para siempre. Mis huesos malvados me gritan. A veces bajito. Otras como lo hago yo cuando necesito quemar energía. O echar fuera todo.
Mi alma no te ve. No sabe donde estás. No sabe dónde te escondes. Donde se mete la gente cuando se acaba la conferencia. Donde te vas cuando acabo mi charla. Cuando me quito el gorro. Cuando ya no tengo el micrófono conectado. Cuando las fotos se acabaron. Donde estas ahora que mi mundo es este café amargo. Esta ventana analógica al mundo. Este sorbo tan pequeño de lo que es vivir. Donde todos los recuerdos bonitos de este confinamiento son solo terciopelo.
Mi televisión llora. Cuando da las noticias. Cuando dan números y números. Curvas. Gráficas. Tendencias. Nunca pensé que las matemáticas pudieran ser tan dolorosas. Cuando yo me presentaba a subir nota en matemáticas si sacaba menos de un notable. Y tengo que limpiar la pantalla con un pañuelo. Porque si no limpias las lágrimas se enraízan y ya no salen como el rocío. Y se congelan. Y el hielo corta los órganos blandos del interior. Los que están cerca de tu corazón.
Solo queda batirse. Y resistir. Y volver al mundo que está ahí fuera. Al círculo de tus brazos. Al calor de esa botella de vino. A abrazar a mi mamá con fuerza. A celebrar los cumpleaños, los santos, los acontecimientos que nos hemos saltado. A caerse al suelo y hacerse una herida en la rodilla tropezándose al correr lejos, muy lejos. A abollar el mundo saltando. A tumbarse exhausto al descender de la bicicleta por el calor, y meterse en una fuente para refrescarse del calor. A sentir cómo se te cuartea la piel con el aire y el sol de la montaña. A bucear buscando peces en mar. A chocar unas cervezas al aire con unos amigos en la barbacoa.
Saludos Malignos!
Autor: Chema Alonso (Contactar con Chema Alonso)
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| Figura 1: Confinamiento |
El café sabe amargo, ya os lo he dicho. Podría haber elegido una taza de café "normal", pero entonces no cabría tanto. Y no quiero vivir la vida a sorbos. Y tampoco soy de pensar que solo hay una forma de hacer las cosas de manera "normal". Nunca lo he sido. Me gusta pensar que eso no es ser hacker. También podría haber sacado una taza de Star Wars, de las grandes, pero esas son de mi colección.
Me apego a recuerdos. A mis pequeñas cosas que cuando las miro con la realidad aumentada de mi mirada están llenas de historias vivas que danzan frente a mis ojos. En 3D. Con música envolvente. Son casa. Son refugio. Me gusta alejarme un poco de ellos para crear nuevos recuerdos. Solo un poco. Para volver a disfrutarlos más. Y los objetos y recuerdos que vienen conmigo son yo. Son parte de mí, fueran dulces o amargos.
El café sabe amargo, pero no es intenso. Me gusta americano. Largo de agua. Aguachirri. Como lo pido siempre cuando quiero café. Sin leche. Largo como mi jornada laboral. Largo y amargo. Largo como mi pasado. Largo, espero, como mi futuro. Para sentir la experiencia durante más tiempo. Solo un poco más. Nada dura para siempre salvo en la memoria donde el tiempo se pliega. Como en la película esa de "Origen". Un sueño dentro de otro. Recursivo como los algoritmos. No se acaba. Ni lo dulce ni lo amargo. Pero el sabor del café es amargo. Y no quiero vestirlo de algo dulcificado echando mucha azúcar. Un poco para hacerlo más llevadero, puede, pero no mucho más maquillaje. Quiero sentir las cosas como son. Que duelan si tienen que doler. Que amarguen si tienen que amargar.
Mis ojos ya no son lo que eran. Están más cansaditos. Empiezan a pedir tregua de tanta lectura. De tantas letras en pantallas. De tantos mensajes que releí. De tantas y tantas hojas luchando contra mis párpados. De mi cerebro ávido por captar más de todo lo que se ve y lo que no se ve. De tantas luces en aventuras galácticas. Series de superhéroes. O de zombies que decoran el paisaje o antihéroes que van a acabar mal porque toman malas decisiones constantemente intentando avanzar. O porque la serie ya comenzó en un psiquiátrico como declaración de intenciones de lo que nos esperaba por delante.
Mis ojos ya no son lo que eran. Me piden ayuda. Mis ojos. Y se la doy a dosis pequeñas. No quiero que se acomoden. Aún no. Quiero que peleen por descifrar el mundo con sus propias herramientas. Pero de vez en cuando los consuelo. Les echo un poco de azúcar. Dejo que se acunen sobre el cristal de unas lupas de lectura. Para que aguanten más. Para que me descifren el mundo unos minutos más antes de caer rendido en la negrura de la noche.
El día es gris. Igual que ayer. Igual que el otro domingo que hizo buen día. Lo veo desde aquí. Mi sitio es el mismo que llevo ocupando durante este último mes y algo. Un rincón de la existencia con una ventana por la que veo solo un poquito del mundo analógico cuando mi foco se relaja. Solo una esquina de la vida. Por la que miro mientras me amargo mi paladar con el sabor del café. Con las gafas puestas para leer esa presentación con números y letras pequeñitas. Es mi vida. Casi enteramente mi vida es esto ahora.
El día es grande. O será que yo me siento pequeño. Como seguro que te sientes tú. Porque es como si me escondiera. Me siento un poco azul. No. No lo tomes mal. No me disgusta el color. Ni el gris ni el azul. La vida no es solo sol. La vida no es solo color amarillo. No solo luz. El azul es bonito también. Me gusta su olor. Su tacto. Y acurrucarme un rato con una de mis muchas bolitas azules. Esas que tengo en la estantería. Cojo una un rato. Me abrazo a ella. Retozo en mi sofá acurrucándola. O mirando al cielo con mi taza de Winnie The Pooh.
Mi cerebro vuela. Por el cielo. Sé que pronto saldré a jugar con las bolas amarillas. Sé que volveré a salir al parque a jugar con mis amigos. A gritar. A dar abrazos y besos. A ver un partido de fútbol. A ir a escuchar a los poetas rasgar sus guitarras. A sudar. A escuchar los gritos. A pegar los chillidos. A destrozar las canciones por no saber cantar. A mezclar el rojo con el amarillo. A mezclar el amarillo con el azul. A trepar por el monte con mi bicicleta cual motivado. A escuchar la música mientras vagabundeo en soledad por el mundo. Ese al que solo viajo yo. Por otros países. A irme a retozar con Morfeo sin tener que pelear por ello. Correr a sus brazos sin hacer cola en la frontera.
Mis palabras se amontonan. Están ahí. Guardadas. Para ti. Para las cenas. Para las charlas. Para las confesiones. Para los reencuentros. Para cuando las quieras oír. Para cuando las puedas escuchar de mi voz. Para que no sea algo digitalizado. Para que sea el sonido que emito con mis cuerdas vocales directamente. Ese que conecta directo con el motor de mi cuerpo. Ese que escribe cosas que nadie lee. Que nadie escucha. Que nadie le dicta. El inventor de los sentimientos. El pintor de las bolitas.
Mis caricias te extrañan. En los confines de mis dedos. Las noto palpitar cuando golpeo con suavidad las teclas de mi teclado. Cuando escribo algo para nadie. Pidiendo salir. Pidiendo espacio para ellas. Para que no duelan los dedos al final del día por el repiquetear constante. Para que el cansancio no sea solo mecánico sino también cuántico. Para que los dedos se muevan como olas al compás de dunas de ese desierto inmenso en soledad que queda por recorrer. Una vez más. Lentas. Eléctricas. Quemando. Como un calambre que sube por mis antebrazos y enciende el tatuaje imaginario de las llamas que nunca me hice.
La vida sigue escribiendo grietas en mi cara con tinta indeleble. En los surcos de mi piel. Donde guardo lo importante. Las risas. Los recuerdos. Los anhelos. Los planes inconclusos. Los conclusos. Con todos los metadatos. Con los recuerdos que he querido convertir en yo. En casa. Lo mejor de historia, de física y química. De arte. O incluso de filosofía sobre la vida que iba a tener pero que nunca tuve.
Mi pasado se perdió en este futuro. Porque de los mil caminos del multiverso el premio cayó en otra línea temporal. Porque la banda cambió el setlist por el camino. Porque fallé el pie de una estrofa. Porque no afinamos la canción en el mismo tempo. O porque mi diapasón se rompió por usarlo tanto a tanta velocidad. Y cada día puedo leerlos con más intensidad. Cuando me miro al espejo. Las canciones que salieron al final para el elepé son las que tengo escritas en mis arrugas. Pero aún me queda discografía que componer. Ouh, yeah!
Mis huesos me gritan. Cuando subo o bajo una escalera. Cuando recuerdo los golpes en la cadera al caerme de los patines. Cuando me levanto de la silla para preguntarle al sol qué hora es. Cuando pienso en todas las veces que necesito caerme aún. Cuando me veo volando sobre una tabla. Cuando recuerdo la negrura que viene tras la rampa. Cuando me despierto de la oscuridad y me están cosiendo la cabeza. Con sangre en los ojos. Cuando pienso en que el dolor no existe cuando el golpe es suficiente certero como para abrirte la cabeza. Y te quedas en calma para siempre. Mis huesos malvados me gritan. A veces bajito. Otras como lo hago yo cuando necesito quemar energía. O echar fuera todo.
Mi alma no te ve. No sabe donde estás. No sabe dónde te escondes. Donde se mete la gente cuando se acaba la conferencia. Donde te vas cuando acabo mi charla. Cuando me quito el gorro. Cuando ya no tengo el micrófono conectado. Cuando las fotos se acabaron. Donde estas ahora que mi mundo es este café amargo. Esta ventana analógica al mundo. Este sorbo tan pequeño de lo que es vivir. Donde todos los recuerdos bonitos de este confinamiento son solo terciopelo.
Mi televisión llora. Cuando da las noticias. Cuando dan números y números. Curvas. Gráficas. Tendencias. Nunca pensé que las matemáticas pudieran ser tan dolorosas. Cuando yo me presentaba a subir nota en matemáticas si sacaba menos de un notable. Y tengo que limpiar la pantalla con un pañuelo. Porque si no limpias las lágrimas se enraízan y ya no salen como el rocío. Y se congelan. Y el hielo corta los órganos blandos del interior. Los que están cerca de tu corazón.
Solo queda batirse. Y resistir. Y volver al mundo que está ahí fuera. Al círculo de tus brazos. Al calor de esa botella de vino. A abrazar a mi mamá con fuerza. A celebrar los cumpleaños, los santos, los acontecimientos que nos hemos saltado. A caerse al suelo y hacerse una herida en la rodilla tropezándose al correr lejos, muy lejos. A abollar el mundo saltando. A tumbarse exhausto al descender de la bicicleta por el calor, y meterse en una fuente para refrescarse del calor. A sentir cómo se te cuartea la piel con el aire y el sol de la montaña. A bucear buscando peces en mar. A chocar unas cervezas al aire con unos amigos en la barbacoa.
Saludos Malignos!
Autor: Chema Alonso (Contactar con Chema Alonso)
Related links
Saturday, April 25, 2020
How To Start | How To Become An Ethical Hacker
Are you tired of reading endless news stories about ethical hacking and not really knowing what that means? Let's change that!
This Post is for the people that:
- Have No Experience With Cybersecurity (Ethical Hacking)
- Have Limited Experience.
- Those That Just Can't Get A Break
OK, let's dive into the post and suggest some ways that you can get ahead in Cybersecurity.
I receive many messages on how to become a hacker. "I'm a beginner in hacking, how should I start?" or "I want to be able to hack my friend's Facebook account" are some of the more frequent queries. Hacking is a skill. And you must remember that if you want to learn hacking solely for the fun of hacking into your friend's Facebook account or email, things will not work out for you. You should decide to learn hacking because of your fascination for technology and your desire to be an expert in computer systems. Its time to change the color of your hat 😀
I've had my good share of Hats. Black, white or sometimes a blackish shade of grey. The darker it gets, the more fun you have.
If you have no experience don't worry. We ALL had to start somewhere, and we ALL needed help to get where we are today. No one is an island and no one is born with all the necessary skills. Period.OK, so you have zero experience and limited skills…my advice in this instance is that you teach yourself some absolute fundamentals.
Let's get this party started.
- What is hacking?
Hacking is identifying weakness and vulnerabilities of some system and gaining access with it.
Hacker gets unauthorized access by targeting system while ethical hacker have an official permission in a lawful and legitimate manner to assess the security posture of a target system(s)There's some types of hackers, a bit of "terminology".
White hat — ethical hacker.
Black hat — classical hacker, get unauthorized access.
Grey hat — person who gets unauthorized access but reveals the weaknesses to the company.
Script kiddie — person with no technical skills just used pre-made tools.
Hacktivist — person who hacks for some idea and leaves some messages. For example strike against copyright.
- Skills required to become ethical hacker.
- Curosity anf exploration
- Operating System
- Fundamentals of Networking
PHASES OF HACKING
Hacking is broken up into six phases:The more you get close to all phases,the more stealth will be your attack.
1-Reconnaissance-This is the primary phase of hacking where hacker tries to collect as much as information as possible about the target.It includes identifying the target,domain name registration records of the target, mail server records,DNS records.The tools that are widely used in the process is NMAP,Hping,Maltego, and Google Dorks.
2-Scanning-This makes up the base of hacking! This is where planning for attack actually begins! The tools used in this process are Nessus,Nexpose,and NMAP. After reconnaissance the attacker scans the target for services running,open ports,firewall detection,finding out vulnerabilities,operating system detection.
3-Gaining Access-In this process the attacker executes the attack based on vulnerabilities which were identified during scanning! After the successful, he get access to the target network or enter in to the system.The primary tools that is used in this process is Metasploit.
4-Maintaining Access-It is the process where the hacker has already gained access in to a system. After gaining access the hacker, the hacker installs some backdoors in order to enter in to the system when he needs access in this owned system in future. Metasploit is the preffered toll in this process.
5-Clearning track or Covering track-To avoid getting traced and caught,hacker clears all the tracks by clearing all kinds of logs and deleted the uploaded backdoor and anything in this process related stuff which may later reflect his presence!
6-Reporting-Reporting is the last step of finishing the ethical hacking process.Here the Ethical Hacker compiles a report with his findings and the job that was done such as the tools used,the success rate,vulnerabilities found,and the exploit process.
Continue reading
Linux Command Line Hackery Series - Part 4
Welcome back to Linux Command Line Hackery, hope you have enjoyed this series so far. Today we are going to learn new Linux commands and get comfortable with reading text files on Linux.
Suppose that you wanted to view your /etc/passwd file. How will you do that? From what we have learned so far what you'll do is type:
cat /etc/passwd
And there you go, but really did you see all the output in one terminal? No, you just ended up with last few lines and you'll have to cheat (i,e use graphical scroll bar) in order to see all the contents of /etc/passwd file. So is there a command line tool in linux with which we can see all the contents of a file easily without cheating? Yes, there are actually a few of them and in this article we'll look at some common ones.
Command: more
Syntax: more [options] file...
Function: more is a filter for paging through text one screenful at a time. With more we can parse a file one terminal at a time or line by line. We can also go backward and forward a number of lines using more.
So if we're to use more on /etc/passwd file how will we do that? We'll simply type
more /etc/passwd
now we'll get a screenful output of the file and have a prompt at the bottom of terminal. In order to move forward one line at a time press <Enter Key>. Using enter we can scroll through the file one line at a time. If you want to move one screen at a time, you can press <Space Key> to move one screen at a time. There are more functions of more program, you can know about them by pressing <h key>. To exit out of more program simply type <q key> and you'll get out of more program.
Command: less
Syntax: less [options] file...
Function: less is similar to more but less has more functionality than more. less is particularly useful when reading large files as less does not have to read the entire input file before starting, so it starts up quickly than many other editors.
less command is based on more so what you've done above with more can be done with less as well. Try it out yourself.
Command: head
Syntax: head [OPTION]... [FILE]...
Function: head command prints the head or first part of a file. By default head prints out first 10 lines of a file. If more than one file is specified, head prints first 10 lines of all files as a default behavior.
If we want to see only first 10 lines of /etc/passwd we can type:
head /etc/passwd
We can also specify to head how many lines we want to view by using the -n flag. Suppose you want to see first 15 lines of /etc/passwd file you've to type:
head -n 15 /etc/passwd
Ok you can view the first lines of a file what about last lines, is there a tool for that also? Exactly that's what our next command will be about.
Command: tail
Syntax: tail [OPTION]... [FILE]...
Function: tail is opposite of head. It prints the last 10 lines of a file by default. And if more than one file is specified, tail prints last 10 lines of all files by default.
To view last 10 lines of /etc/passwd file you'll type:
tail /etc/passwd
and as is the case with head -n flag can be used to specify the number of lines
tail -n 15 /etc/passwd
Now one more thing that we're going to learn today is grep.
Command: grep
Syntax: grep [OPTIONS] PATTERN [FILE...]
Function: grep is used to search a file for lines matching the pattern specified in the command.
A PATTERN can simply be a word like "hello" or it can be a regular expression (in geek speak regex). If you aren't familiar with regex, it's ok we'll not dive into that it's a very big topic but if you want to learn about it I'll add a link at the end of this article that will help you get started with regex.
Now back to grep say we want to find a line in /etc/passwd file which contains my user if we'll simply type:
grep myusername /etc/passwd
Wohoo! It gives out just that data that we're looking for. Remember here myusername is your username.
One cool flag of grep is -v which is used to look in file for every line except the line containing the PATTERN specified after -v [it's lowercase v].
Take your time practicing with these commands especially grep and more. We'll learn a lot more about grep in other upcoming articles.
References:
https://en.wikipedia.org/wiki/Regular_expression
http://www.regular-expressions.info/
Awesome website to learn Regular expressions - http://www.regexr.com/
Related links
Top 20 Android Spy Apps That Will.Make U Fell Like A Dectitive
Top 10 Best android spy apps.
t's worth to note that there are plenty of Android spy apps available on the Google Play Store, but mentioning all of them is not possible. So, in this article, we have listed the one that's popular and used by many. So, let's explore the list of best spy apps 2019.
#1 Spy Camera OS
This app permits users to capture images secretly. This app provides a smart way to shoot photos with a hidden camera interface so people wouldn't notice that you are taking pictures of them. Also, every sound and flash etc get disabled in this app.
#2 Ear Spy
This is an awesome app to record even low voices. By this app, you can place your phone in the other room and can listen to the voices of that room by your Bluetooth handset. This app actually records the sound and then amplifies its recording and give you the amplified clear voices.
#3 Ip Cam Viewer
This awesome app allows to remotely view and control your IP Camera, DVR, Network Video Recorder, traffic cameras, CCTV or WebCam from an android device. In its new version, you can also get the notification on detecting motion on the device. This app can automatically start recording whenever it detects motion.
#4 Automatic Call Recorder
This is another best Spy App that one can have on their Android smartphone. This app gets automatically launched whenever you make or receive any call. It records all the conversation b/w speakers and also the surrounding noise of the device in which it is installed.
#5 Monitor Call Sms Location
This is another good spy app to remotely monitor SMS, Photo, Location, call logs and many more things on an Android device. This will exact location of the targeted device through a web-portal even if GPS disabled on the target device. The app comes with the three-day free trial option.
#6 Anti Spy Mobile
You don't know whether you had installed any spyware software on your phone? Use this app to instantly find the spyware. The Android app uses advanced detection techniques to detect new spyware. So, with this app, you can easily protect yourself from Android spyware.
#7 Hidden Eye
Ever wanted to know who tried snooping on your phone while you were away. Your friends or family member might have tried to unlock your phone. Hidden Eye is a simple app with no frills that will photograph the person when they try to unlock your phone.
#8 AppLock
Applock is the most downloaded app lock in Play Store. Protect privacy with password, pattern, fingerprint lock. AppLock can lock Facebook, Whatsapp, Gallery, Messenger, SMS, Contacts, Gmail, Settings, incoming calls and any app you choose. Prevent unauthorized access and guard privacy. Ensure security.
#9 Hide Calls Automatically
With this app, all outgoing, incoming and missed calls coming from private contacts will be deleted automatically from calls Log of your phone! No icon of this app will appear in your list of applications on your phone.
#10 Truecaller: Caller ID & Dialer
Truecaller is the only dialer you'll ever need with the ability to identify unknown callers and block unwanted calls. See names and photos of people who call, even if they aren't saved in your phonebook. And know when friends are free to talk, making your calling experience smarter and more delightful.
#11 Cell Tracker
You can use the cell tracker Android app to keep track of the location of your smartphone. With the help of this app, you can track all the locations you have visited in the last few days with your Android phone. To check the locations visited you have to launch the app and click on "View Now". No need to turn on the GPS.
#12 Secret Calls
With the help of this app, all outgoing, Incoming and Missed Calls coming from private contacts will be deleted automatically from Calls Log of your phone! No icon of this app will appear in your list of applications on your phone.
#13 Spy Camera
This is another Spy app on the list which provides one-touch to capture image feature. The app actually has lots of useful features. With the help of this app, you can find your lost phone because this app allows you to set up a number. When you lost your phone, just SMS to this phone and it will take a picture and upload to drive.
#14 Truecaller
Truecaller is a popular Android app which is used every day to identify unknown calls, block spam calls and spam SMS. It filters out the unwanted and lets you connect with people who matter.
#15 Whoscall – Caller ID
Whoscall, the best caller ID App that identifies unknown calls and blocks annoying spams, robocall & telemarketing with more than 50 million downloads and over 1 billion numbers data. It also got the call blocker that can be used to blacklist or whitelist contacts stored on your smartphone.
#16 Norton Family parental control
Norton Family parental control is basically an Android app that is meant to keep kids safe online. However, this is nothing sort of a spy app. The app can help you to supervise online activity. You can easily keep track of sites which your friend visit and what they search if you install Norton Family Parental control on their phone.
#17 Smart Hide Calculator
The app doesn't help users to spy on others. But, it can give you a detective type feeling. Smart hide calculator is a fully functional calculator app but with a little twist. Once you enter the password and press the '=' button then boom you are presented to an interface where you can hide, unhide pictures, videos, documents or files with any file extension.
#18 Hidden Eye
Ever wanted to know who tried snooping into your phone while you were away. Your friends or family member might have tried to unlock your phone. Hidden Eye is a simple app with no frills that will photograph the person when they try to unlock your phone.
#19 Background Video Recorder
This is another best Android spy app that helps users to record what's happening behind them. Background Video Recorder is basically a camera app that records videos silently on the background. The app eliminates the camera shutter sounds, camera previews and it can also record videos when the screen is off.
#20 Kids Place
Kids Place is another best parental control app in the list and its meant to protect your kids' online activities. However, if you don't have kids, you can use the app to track other devices. The app gives you full control over other devices and you can control everything including calls, text, internet browsing, apps, etc.
@EVERYTHING NT
Continue reading
RapidScan: The Multi-Tool Website Vulnerabilities Scanner With Artificial Intelligence
RapidScan's Features:
For Your Infomation about RapidScan:
RapidScan supports checking for these vulnerabilities:
RapidScan's screenshots:
How to contribute? If you want to contribute to the author. Read this.
- One-step installation.
- Executes a multitude of security scanning tools, does other custom coded checks and prints the results spontaneously.
- Come of the tools include
nmap,dnsrecon,wafw00f,uniscan,sslyze,fierce,lbd,theharvester,dnswalk,golismeroetc executes under one entity. - Saves a lot of time, indeed a lot time!
- Checks for same vulnerabilities with multiple tools to help you zero-in on false positives effectively.
- Legends to help you understand which tests may take longer time, so you can Ctrl+C to skip if needed.
- Association with OWASP Top 10 2017 on the list of vulnerabilities discovered. (under development)
- Critical, high, large, low and informational classification of vulnerabilities.
- Vulnerability definitions guides you what the vulnerability actually is and the threat it can pose
- Remediations tells you how to plug/fix the found vulnerability.
- Executive summary gives you an overall context of the scan performed with critical, high, low and informational issues discovered. (under development)
- Artificial intelligence to deploy tools automatically depending upon the issues found. for eg; automates the launch of
wpscanandplecosttools when a wordpress installation is found. (under development) - Detailed comprehensive report in a portable document format (
*.pdf) with complete details of the scans and tools used. (under development)
For Your Infomation about RapidScan:
- Program is still under development, works and currently supports 80 vulnerability tests.
- Parallel processing is not yet implemented, may be coded as more tests gets introduced.
RapidScan supports checking for these vulnerabilities:
- DNS/HTTP Load Balancers & Web Application Firewalls.
- Checks for Joomla, WordPress and Drupal
- SSL related Vulnerabilities (HEARTBLEED, FREAK, POODLE, CCS Injection, LOGJAM, OCSP Stapling).
- Commonly Opened Ports.
- DNS Zone Transfers using multiple tools (Fierce, DNSWalk, DNSRecon, DNSEnum).
- Sub-Domains Brute Forcing.
- Open Directory/File Brute Forcing.
- Shallow XSS, SQLi and BSQLi Banners.
- Slow-Loris DoS Attack, LFI (Local File Inclusion), RFI (Remote File Inclusion) & RCE (Remote Code Execution).
RapidScan's Requirements:
- Kali Linux, Parrot Security OS, BlackArch... Linux distros that based for pentesters and hackers.
- Python 2.7.x
RapidScan Installation:
RapidScan's screenshots:
 |
| RapidScan helping menu |
 |
| RapidScan Intro |
 |
| RapidScan Outro |
How to contribute? If you want to contribute to the author. Read this.
More info
Friday, April 24, 2020
WHY WE DO HACKING?
Purpose of Hacking?
. Just for fun
.Show-off
.Steal important information
.Damaging the system
.Hampering Privacy
.Money Extortion
.System Security Testing
.To break policy compliance etc
More articles. Just for fun
.Show-off
.Steal important information
.Damaging the system
.Hampering Privacy
.Money Extortion
.System Security Testing
.To break policy compliance etc
BeEF: Browser Exploitation Framework
"BeEF is the browser exploitation framework. A professional tool to demonstrate the real-time impact of XSS browser vulnerabilities. Development has focused on creating a modular structure making new module development a trivial process with the intelligence residing within BeEF. Current modules include the first public Inter-protocol Exploit, a traditional browser overflow exploit, port scanning, keylogging, clipboard theft and more." read more...Website: http://www.bindshell.net/tools/beef
Related links
Thursday, April 23, 2020
How To Install And Run Backtrack On Android
Guide you step by step to How to install and run Backtrack on android. As the Backtrack is also available with ARM architecture which makes it possible to run Backtrack on an ARM machine such as mobiles or tablets.
Recently, We are discussed Install and Run BackTrack on Windows. Android is the best OS for penetration testing. It designed for digital forensics and penetration testing or hacking tool. It comes with many more updated tools. As the Backtrack is also available with ARM architecture which makes it possible to run Backtrack on an ARM machine such as mobiles or tablets.
How To Install and Run Backtrack On AndroidRequirements
- A Rooted Device [ Root Simple Android Phone Without Pc ]
- Backtrack ARM [ Download ]
- BusyBox [ Download ]
- Android Terminal and Android VNC
- If you are using PC then you need 7zip for extraction otherwise you can use zarchiver on your android phone. [ Download ]
Step to Install and Run Backtrack On Android:
First of all extract the BT5-GNOME-ARM.7z. and copy the "BT5" folder and then put in your phone's root directory. Here mine phone is /sdcard. The root directory is different for different mobile devices.
- Now install all the above apps Busybox, Android Terminal, Android Vnc.
- After installing BusyBox application open it and wait until it finishes loading and then click on Smart install.
- Now open the android terminal and type the following command:
su cd /sdcard/BT5sh bootbtNOTE :- When you type su in terminal it will ask you for superuser request and you have to tap on Grant. - After this, type the following commands in terminal.
export USER=rootvncpasswd - After entering vncpasswd the terminal will ask you to enter the password. Enter the desired password and hit enter.
- Now type the following commands.
tightvncserver -geometry 1280×720 - The terminal emulator will create the localhost to connect it to VNC server. Now note the localhost port marked red below. Now minimize the terminal emulator.
- Open the Android VNC and type the following settings.
Nickname : BT5
Password : your password here which you entered in terminal (step no.6)
Address : localhost
Port : 5906
Password : your password here which you entered in terminal (step no.6)
Address : localhost
Port : 5906
NOTE: Make sure that your localhost's port matches with terminal's localhost. Here mine New 'X' desktop is localhost:6. You may be different. So, in VNC type Port 590X where the "X" is the localhost in the android terminal.
That's it now just tap on connect to run the Backtrack on your android. So in this way you successfully install and run backtrack 5 on android. If you face any problem feel free to discuss in below comments!
Read more
The History And Evolution Of Java
CHAPTER
1 The History and Evolution of Java
To fully understand Java, one must understand the reasons behind its creation, the forces that shaped it, and the legacy that it inherits. Like the successful computer languages that came before, Java is a blend of the best elements of its rich heritage combined with the innovative concepts required by its unique mission. While the remaining chapters of
this book describe the practical aspects of Java—including its syntax, key libraries, and applications—this chapter explains how and why Java came about, what makes it so important, and how it has evolved over the years.
Although Java has become inseparably linked with the online environment of the Internet, it is important to remember that Java is first and foremost a programming language. Computer language innovation and development occurs for two fundamental reasons:
• To adapt to changing environments and uses
• To implement refinements and improvements in the art of programming
As you will see, the development of Java was driven by both elements in nearly equal measure.
Java's Lineage
Java is related to C++, which is a direct descendant of C. Much of the character of Java is inherited from these two languages. From C, Java derives its syntax. Many of Java's object- oriented features were influenced by C++. In fact, several of Java's defining characteristics come from—or are responses to—its predecessors. Moreover, the creation of Java was deeply rooted in the process of refinement and adaptation that has been occurring in computer programming languages for the past several decades. For these reasons, this section reviews the sequence of events and forces that led to Java. As you will see, each innovation in language design was driven by the need to solve a fundamental problem that the preceding languages could not solve. Java is no exception.
3
The Birth of Modern Programming: C
The C language shook the computer world. Its impact should not be underestimated, because it fundamentally changed the way programming was approached and thought about. The creation of C was a direct result of the need for a structured, efficient, high-level language that could replace assembly code when creating systems programs. As you probably know, when a computer language is designed, trade-offs are often made, such as the following:
• Ease-of-use versus power
• Safety versus efficiency
• Rigidity versus extensibility
Prior to C, programmers usually had to choose between languages that optimized one set of traits or the other. For example, although FORTRAN could be used to write fairly efficient programs for scientific applications, it was not very good for system code. And while BASIC was easy to learn, it wasn't very powerful, and its lack of structure made its usefulness questionable for large programs. Assembly language can be used to produce highly efficient programs, but it is not easy to learn or use effectively. Further, debugging assembly code can be quite difficult.
Another compounding problem was that early computer languages such as BASIC, COBOL, and FORTRAN were not designed around structured principles. Instead, they relied upon the GOTO as a primary means of program control. As a result, programs written using these languages tended to produce "spaghetti code"—a mass of tangled jumps and conditional branches that make a program virtually impossible to understand. While languages like Pascal are structured, they were not designed for efficiency, and failed to include certain features necessary to make them applicable to a wide range of programs. (Specifically, given the standard dialects of Pascal available at the time, it was not practical to consider using Pascal for systems-level code.)
So, just prior to the invention of C, no one language had reconciled the conflicting attributes that had dogged earlier efforts. Yet the need for such a language was pressing. By the early 1970s, the computer revolution was beginning to take hold, and the demand for software was rapidly outpacing programmers' ability to produce it. A great deal of effort was being expended in academic circles in an attempt to create a better computer language.
But, and perhaps most importantly, a secondary force was beginning to be felt. Computer hardware was finally becoming common enough that a critical mass was being reached. No longer were computers kept behind locked doors. For the first time, programmers were gaining virtually unlimited access to their machines. This allowed the freedom to experiment. It also allowed programmers to begin to create their own tools. On the eve of C's creation, the stage was set for a quantum leap forward in computer languages.
Invented and first implemented by Dennis Ritchie on a DEC PDP-11 running the UNIX operating system, C was the result of a development process that started with an older language called BCPL, developed by Martin Richards. BCPL influenced a language called B, invented by Ken Thompson, which led to the development of C in the 1970s. For many years, the de facto standard for C was the one supplied with the UNIX operating system and described in The C Programming Language by Brian Kernighan and Dennis Ritchie (Prentice- Hall, 1978). C was formally standardized in December 1989, when the American National Standards Institute (ANSI) standard for C was adopted.
The creation of C is considered by many to have marked the beginning of the modern age of computer languages. It successfully synthesized the conflicting attributes that had so troubled earlier languages. The result was a powerful, efficient, structured language that was relatively easy to learn. It also included one other, nearly intangible aspect: it was a programmer's language. Prior to the invention of C, computer languages were generally designed either as academic exercises or by bureaucratic committees. C is different. It was designed, implemented, and developed by real, working programmers, reflecting the way that they approached the job of programming. Its features were honed, tested, thought about, and rethought by the people who actually used the language. The result was a language that programmers liked to use. Indeed, C quickly attracted many followers
who had a near-religious zeal for it. As such, it found wide and rapid acceptance in the programmer community. In short, C is a language designed by and for programmers. As you will see, Java inherited this legacy.
C++: The Next Step
During the late 1970s and early 1980s, C became the dominant computer programming language, and it is still widely used today. Since C is a successful and useful language, you might ask why a need for something else existed. The answer is complexity. Throughout the history of programming, the increasing complexity of programs has driven the need for better ways to manage that complexity. C++ is a response to that need. To better understand why managing program complexity is fundamental to the creation of C++, consider the following.
Approaches to programming have changed dramatically since the invention of the computer. For example, when computers were first invented, programming was done by manually toggling in the binary machine instructions by use of the front panel. As long as programs were just a few hundred instructions long, this approach worked. As programs grew, assembly language was invented so that a programmer could deal with larger, increasingly complex programs by using symbolic representations of the machine instructions. As programs continued to grow, high-level languages were introduced that gave the programmer more tools with which to handle complexity.
The first widespread language was, of course, FORTRAN. While FORTRAN was an impressive first step, it is hardly a language that encourages clear and easy-to-understand programs. The 1960s gave birth to structured programming. This is the method of programming championed by languages such as C. The use of structured languages enabled programmers to write, for the first time, moderately complex programs fairly easily. However, even with structured programming methods, once a project reaches a certain size, its complexity exceeds what a programmer can manage. By the early 1980s, many projects were pushing the structured approach past its limits. To solve this problem, a new way to program was invented, called object-oriented programming (OOP). Object-oriented programming is discussed in detail later in this book, but here is a brief definition: OOP is a programming methodology that helps organize complex programs through the use of inheritance, encapsulation, and polymorphism.
In the final analysis, although C is one of the world's great programming languages, there is a limit to its ability to handle complexity. Once the size of a program exceeds a certain point, it becomes so complex that it is difficult to grasp as a totality. While the precise size at which this occurs differs, depending upon both the nature of the program and the programmer, there is always a threshold at which a program becomes unmanageable.
C++ added features that enabled this threshold to be broken, allowing programmers to comprehend and manage larger programs.
C++ was invented by Bjarne Stroustrup in 1979, while he was working at Bell Laboratories in Murray Hill, New Jersey. Stroustrup initially called the new language "C with Classes." However, in 1983, the name was changed to C++. C++ extends C by adding object-oriented features. Because C++ is built on the foundation of C, it includes all of C's features, attributes, and benefits. This is a crucial reason for the success of C++ as a language. The invention of C++ was not an attempt to create a completely new programming language. Instead, it was an enhancement to an already highly successful one.
The Stage Is Set for Java
By the end of the 1980s and the early 1990s, object-oriented programming using C++ took hold. Indeed, for a brief moment it seemed as if programmers had finally found the perfect language. Because C++ blended the high efficiency and stylistic elements of C with the object-oriented paradigm, it was a language that could be used to create a wide range of programs. However, just as in the past, forces were brewing that would, once again, drive computer language evolution forward. Within a few years, the World Wide Web and the Internet would reach critical mass. This event would precipitate another revolution in programming.
The Creation of Java
Java was conceived by James Gosling, Patrick Naughton, Chris Warth, Ed Frank, and Mike Sheridan at Sun Microsystems, Inc. in 1991. It took 18 months to develop the first working version. This language was initially called "Oak," but was renamed "Java" in 1995. Between the initial implementation of Oak in the fall of 1992 and the public announcement of Java in the spring of 1995, many more people contributed to the design and evolution of the language. Bill Joy, Arthur van Hoff, Jonathan Payne, Frank Yellin, and Tim Lindholm were key contributors to the maturing of the original prototype.
Somewhat surprisingly, the original impetus for Java was not the Internet! Instead, the primary motivation was the need for a platform-independent (that is, architecture-neutral) language that could be used to create software to be embedded in various consumer electronic devices, such as microwave ovens and remote controls. As you can probably guess, many different types of CPUs are used as controllers. The trouble with C and C++ (and most other languages) is that they are designed to be compiled for a specific target. Although it is possible to compile a C++ program for just about any type of CPU, to do so requires a full C++ compiler targeted for that CPU. The problem is that compilers are expensive and time-consuming to create. An easier—and more cost-efficient—solution
was needed. In an attempt to find such a solution, Gosling and others began work on a portable, platform-independent language that could be used to produce code that would run on a variety of CPUs under differing environments. This effort ultimately led to the creation of Java.
About the time that the details of Java were being worked out, a second, and ultimately more important, factor was emerging that would play a crucial role in the future of Java.
This second force was, of course, the World Wide Web. Had the Web not taken shape at about the same time that Java was being implemented, Java might have remained a useful but obscure language for programming consumer electronics. However, with the emergence
of the World Wide Web, Java was propelled to the forefront of computer language design, because the Web, too, demanded portable programs.
Most programmers learn early in their careers that portable programs are as elusive as they are desirable. While the quest for a way to create efficient, portable (platform-independent) programs is nearly as old as the discipline of programming itself, it had taken a back seat
to other, more pressing problems. Further, because (at that time) much of the computer world had divided itself into the three competing camps of Intel, Macintosh, and UNIX, most programmers stayed within their fortified boundaries, and the urgent need for portable code was reduced. However, with the advent of the Internet and the Web, the old problem of portability returned with a vengeance. After all, the Internet consists of a
diverse, distributed universe populated with various types of computers, operating systems, and CPUs. Even though many kinds of platforms are attached to the Internet, users would like them all to be able to run the same program. What was once an irritating but low- priority problem had become a high-profile necessity.
By 1993, it became obvious to members of the Java design team that the problems of portability frequently encountered when creating code for embedded controllers are also found when attempting to create code for the Internet. In fact, the same problem that Java was initially designed to solve on a small scale could also be applied to the Internet on a large scale. This realization caused the focus of Java to switch from consumer electronics to Internet programming. So, while the desire for an architecture-neutral programming language provided the initial spark, the Internet ultimately led to Java's large-scale success.
As mentioned earlier, Java derives much of its character from C and C++. This is by intent. The Java designers knew that using the familiar syntax of C and echoing the object-oriented features of C++ would make their language appealing to the legions of experienced C/C++ programmers. In addition to the surface similarities, Java shares some of the other attributes that helped make C and C++ successful. First, Java was designed, tested, and refined by real, working programmers. It is a language grounded in the needs and experiences of the people who devised it. Thus, Java is a programmer's language. Second, Java is cohesive and logically consistent. Third, except for those constraints imposed by the Internet environment, Java gives you, the programmer, full control. If you program well, your programs reflect it. If you program poorly, your programs reflect that, too. Put differently, Java is not a language with training wheels. It is a language for professional programmers.
Because of the similarities between Java and C++, it is tempting to think of Java as simply the "Internet version of C++." However, to do so would be a large mistake. Java has significant practical and philosophical differences. While it is true that Java was influenced by C++, it is not an enhanced version of C++. For example, Java is neither upwardly nor downwardly compatible with C++. Of course, the similarities with C++ are significant, and if you are a C++ programmer, then you will feel right at home with Java. One other point: Java was not designed to replace C++. Java was designed to solve a certain set of problems. C++ was designed to solve a different set of problems. Both will coexist for many years to come.
As mentioned at the start of this chapter, computer languages evolve for two reasons:
to adapt to changes in environment and to implement advances in the art of programming. The environmental change that prompted Java was the need for platform-independent programs destined for distribution on the Internet. However, Java also embodies changes in the way that people approach the writing of programs. For example, Java enhanced
and refined the object-oriented paradigm used by C++, added integrated support for multithreading, and provided a library that simplified Internet access. In the final analysis,
though, it was not the individual features of Java that made it so remarkable. Rather, it was the language as a whole. Java was the perfect response to the demands of the then newly emerging, highly distributed computing universe. Java was to Internet programming what C was to system programming: a revolutionary force that changed the world.
The C# Connection
The reach and power of Java continues to be felt in the world of computer language development. Many of its innovative features, constructs, and concepts have become part of the baseline for any new language. The success of Java is simply too important to ignore.
Perhaps the most important example of Java's influence is C#. Created by Microsoft to support the .NET Framework, C# is closely related to Java. For example, both share the same general syntax, support distributed programming, and utilize the same object model. There are, of course, differences between Java and C#, but the overall "look and feel" of these languages is very similar. This "cross-pollination" from Java to C# is the strongest testimonial to date that Java redefined the way we think about and use a computer language.
How Java Changed the Internet
The Internet helped catapult Java to the forefront of programming, and Java, in turn, had a profound effect on the Internet. In addition to simplifying web programming in general, Java innovated a new type of networked program called the applet that changed the way the online world thought about content. Java also addressed some of the thorniest issues associated with the Internet: portability and security. Let's look more closely at each of these.
Java Applets
An applet is a special kind of Java program that is designed to be transmitted over the Internet and automatically executed by a Java-compatible web browser. Furthermore, an applet is downloaded on demand, without further interaction with the user. If the user clicks a link that contains an applet, the applet will be automatically downloaded and run in the browser. Applets are intended to be small programs. They are typically used to display data provided by the server, handle user input, or provide simple functions, such as a loan calculator, that execute locally, rather than on the server. In essence, the applet allows some functionality to be moved from the server to the client.
The creation of the applet changed Internet programming because it expanded the universe of objects that can move about freely in cyberspace. In general, there are two very broad categories of objects that are transmitted between the server and the client: passive information and dynamic, active programs. For example, when you read your e-mail, you are viewing passive data. Even when you download a program, the program's code is still only passive data until you execute it. By contrast, the applet is a dynamic, self-executing program. Such a program is an active agent on the client computer, yet it is initiated by the server.
As desirable as dynamic, networked programs are, they also present serious problems in the areas of security and portability. Obviously, a program that downloads and executes automatically on the client computer must be prevented from doing harm. It must also be able to run in a variety of different environments and under different operating systems. As you will see, Java solved these problems in an effective and elegant way. Let's look a bit more closely at each.
Security
As you are likely aware, every time you download a "normal" program, you are taking a risk, because the code you are downloading might contain a virus, Trojan horse, or other harmful code. At the core of the problem is the fact that malicious code can cause its damage because it has gained unauthorized access to system resources. For example, a virus program might gather private information, such as credit card numbers, bank account balances, and passwords, by searching the contents of your computer's local file system. In order for Java to enable applets to be downloaded and executed on the client computer safely, it was necessary to prevent an applet from launching such an attack.
Java achieved this protection by confining an applet to the Java execution environment and not allowing it access to other parts of the computer. (You will see how this is accomplished shortly.) The ability to download applets with confidence that no harm will be done and that no security will be breached is considered by many to be the single most innovative aspect of Java.
Portability
Portability is a major aspect of the Internet because there are many different types of computers and operating systems connected to it. If a Java program were to be run on virtually any computer connected to the Internet, there needed to be some way to enable that program to execute on different systems. For example, in the case of an applet, the same applet must be able to be downloaded and executed by the wide variety of CPUs, operating systems, and browsers connected to the Internet. It is not practical to have different versions of the applet for different computers. The same code must work on all computers. Therefore, some means of generating portable executable code was needed. As you will soon see, the same mechanism that helps ensure security also helps create portability.
Java's Magic: The Bytecode
The key that allows Java to solve both the security and the portability problems just described is that the output of a Java compiler is not executable code. Rather, it is bytecode. Bytecode is a highly optimized set of instructions designed to be executed by the Java run-time system, which is called the Java Virtual Machine (JVM). In essence, the original JVM was designed as an interpreter for bytecode. This may come as a bit of a surprise since many modern languages are designed to be compiled into executable code because of performance concerns.
However, the fact that a Java program is executed by the JVM helps solve the major problems associated with web-based programs. Here is why.
Translating a Java program into bytecode makes it much easier to run a program in a wide variety of environments because only the JVM needs to be implemented for each platform. Once the run-time package exists for a given system, any Java program can run
on it. Remember, although the details of the JVM will differ from platform to platform, all understand the same Java bytecode. If a Java program were compiled to native code, then different versions of the same program would have to exist for each type of CPU connected to the Internet. This is, of course, not a feasible solution. Thus, the execution of bytecode by the JVM is the easiest way to create truly portable programs.
The fact that a Java program is executed by the JVM also helps to make it secure.
Because the JVM is in control, it can contain the program and prevent it from generating
side effects outside of the system. As you will see, safety is also enhanced by certain restrictions that exist in the Java language.
In general, when a program is compiled to an intermediate form and then interpreted by a virtual machine, it runs slower than it would run if compiled to executable code.
However, with Java, the differential between the two is not so great. Because bytecode has been highly optimized, the use of bytecode enables the JVM to execute programs much faster than you might expect.
Although Java was designed as an interpreted language, there is nothing about Java that prevents on-the-fly compilation of bytecode into native code in order to boost performance. For this reason, the HotSpot technology was introduced not long after Java's initial release. HotSpot provides a Just-In-Time (JIT) compiler for bytecode. When a JIT compiler is part of the JVM, selected portions of bytecode are compiled into executable code in real time, on a piece-by-piece, demand basis. It is important to understand that it is not practical to compile an entire Java program into executable code all at once, because Java performs various run-time checks that can be done only at run time. Instead, a JIT compiler compiles code as it is needed, during execution. Furthermore, not all sequences of bytecode are compiled—only those that will benefit from compilation. The remaining code is simply interpreted. However, the just-in-time approach still yields a significant performance boost. Even when dynamic compilation is applied to bytecode, the portability and safety features still apply, because the JVM is still in charge of the execution environment.
Servlets: Java on the Server Side
As useful as applets can be, they are just one half of the client/server equation. Not long after the initial release of Java, it became obvious that Java would also be useful on the server side. The result was the servlet. A servlet is a small program that executes on the server. Just as applets dynamically extend the functionality of a web browser, servlets dynamically extend the functionality of a web server. Thus, with the advent of the servlet, Java spanned both sides of the client/server connection.
Servlets are used to create dynamically generated content that is then served to the client. For example, an online store might use a servlet to look up the price for an item in a database. The price information is then used to dynamically generate a web page that is sent to the browser. Although dynamically generated content is available through mechanisms such as CGI (Common Gateway Interface), the servlet offers several advantages, including increased performance.
Because servlets (like all Java programs) are compiled into bytecode and executed by the JVM, they are highly portable. Thus, the same servlet can be used in a variety of different server environments. The only requirements are that the server support the JVM and a servlet container.
The Java Buzzwords
No discussion of Java's history is complete without a look at the Java buzzwords. Although the fundamental forces that necessitated the invention of Java are portability and security, other factors also played an important role in molding the final form of the language. The key considerations were summed up by the Java team in the following list of buzzwords:
• Simple
• Secure
• Portable
• Object-oriented
• Robust
• Multithreaded
• Architecture-neutral
• Interpreted
• High performance
• Distributed
• Dynamic
Two of these buzzwords have already been discussed: secure and portable. Let's examine what each of the others implies.
Simple
Java was designed to be easy for the professional programmer to learn and use effectively. Assuming that you have some programming experience, you will not find Java hard to master. If you already understand the basic concepts of object-oriented programming, learning Java will be even easier. Best of all, if you are an experienced C++ programmer, moving to Java will require very little effort. Because Java inherits the C/C++ syntax and many of the object- oriented features of C++, most programmers have little trouble learning Java.
Object-Oriented
Although influenced by its predecessors, Java was not designed to be source-code compatible with any other language. This allowed the Java team the freedom to design with a blank slate. One outcome of this was a clean, usable, pragmatic approach to objects. Borrowing liberally from many seminal object-software environments of the last few decades, Java manages to strike a balance between the purist's "everything is an object" paradigm and
the pragmatist's "stay out of my way" model. The object model in Java is simple and easy to extend, while primitive types, such as integers, are kept as high-performance nonobjects.
Robust
The multiplatformed environment of the Web places extraordinary demands on a program, because the program must execute reliably in a variety of systems. Thus, the ability to create robust programs was given a high priority in the design of Java. To gain reliability, Java restricts you in a few key areas to force you to find your mistakes early in program development. At the same time, Java frees you from having to worry about many of the most common causes of programming errors. Because Java is a strictly typed language, it checks your code at compile time. However, it also checks your code at run time. Many hard-to-track-down bugs that often turn up in hard-to-reproduce run-time situations are simply impossible to create in Java. Knowing that what you have written
will behave in a predictable way under diverse conditions is a key feature of Java.
To better understand how Java is robust, consider two of the main reasons for program failure: memory management mistakes and mishandled exceptional conditions (that is, run-time errors). Memory management can be a difficult, tedious task in traditional
programming environments. For example, in C/C++, the programmer must manually allocate and free all dynamic memory. This sometimes leads to problems, because programmers will either forget to free memory that has been previously allocated or, worse, try to free some memory that another part of their code is still using. Java virtually eliminates these problems by managing memory allocation and deallocation for you. (In fact, deallocation is completely automatic, because Java provides garbage collection for unused objects.) Exceptional conditions in traditional environments often arise in situations such as division by zero or "file not found," and they must be managed with clumsy and hard-to-read constructs. Java helps in this area by providing object-oriented exception handling. In a well-written Java program, all run-time errors can—and should—be managed by your program.
Multithreaded
Java was designed to meet the real-world requirement of creating interactive, networked programs. To accomplish this, Java supports multithreaded programming, which allows you to write programs that do many things simultaneously. The Java run-time system comes with an elegant yet sophisticated solution for multiprocess synchronization that enables you to construct smoothly running interactive systems. Java's easy-to-use approach to multithreading allows you to think about the specific behavior of your program, not the multitasking subsystem.
Architecture-Neutral
A central issue for the Java designers was that of code longevity and portability. At the time of Java's creation, one of the main problems facing programmers was that no guarantee existed that if you wrote a program today, it would run tomorrow—even on the same machine. Operating system upgrades, processor upgrades, and changes in core system resources can all combine to make a program malfunction. The Java designers made several hard decisions in the Java language and the Java Virtual Machine in an attempt to alter this situation. Their goal was "write once; run anywhere, any time, forever." To a great extent, this goal was accomplished.
Interpreted and High Performance
As described earlier, Java enables the creation of cross-platform programs by compiling into an intermediate representation called Java bytecode. This code can be executed on any system that implements the Java Virtual Machine. Most previous attempts at cross-platform solutions have done so at the expense of performance. As explained earlier, the Java bytecode was carefully designed so that it would be easy to translate directly into native machine code for very high performance by using a just-in-time compiler. Java run-time systems that provide this feature lose none of the benefits of the platform-independent code.
Distributed
Java is designed for the distributed environment of the Internet because it handles TCP/IP protocols. In fact, accessing a resource using a URL is not much different from accessing a file. Java also supports Remote Method Invocation (RMI). This feature enables a program to invoke methods across a network.
Dynamic
Java programs carry with them substantial amounts of run-time type information that is used to verify and resolve accesses to objects at run time. This makes it possible to dynamically link
code in a safe and expedient manner. This is crucial to the robustness of the Java environment, in which small fragments of bytecode may be dynamically updated on a running system.
The Evolution of Java
The initial release of Java was nothing short of revolutionary, but it did not mark the end of Java's era of rapid innovation. Unlike most other software systems that usually settle into a pattern of small, incremental improvements, Java continued to evolve at an explosive pace. Soon after the release of Java 1.0, the designers of Java had already created Java 1.1. The features added by Java 1.1 were more significant and substantial than the increase in the minor revision number would have you think. Java 1.1 added many new library elements, redefined the way events are handled, and reconfigured many features of the 1.0 library. It also deprecated (rendered obsolete) several features originally defined by Java 1.0. Thus, Java 1.1 both added to and subtracted from attributes of its original specification.
The next major release of Java was Java 2, where the "2" indicates "second generation." The creation of Java 2 was a watershed event, marking the beginning of Java's "modern age." The first release of Java 2 carried the version number 1.2. It may seem odd that the first release of Java 2 used the 1.2 version number. The reason is that it originally referred to the internal version number of the Java libraries, but then was generalized to refer to the entire release. With Java 2, Sun repackaged the Java product as J2SE (Java 2 Platform Standard Edition), and the version numbers began to be applied to that product.
Java 2 added support for a number of new features, such as Swing and the Collections Framework, and it enhanced the Java Virtual Machine and various programming tools. Java 2 also contained a few deprecations. The most important affected the Thread class in which the methods suspend( ), resume( ), and stop( ) were deprecated.
J2SE 1.3 was the first major upgrade to the original Java 2 release. For the most part, it added to existing functionality and "tightened up" the development environment. In
general, programs written for version 1.2 and those written for version 1.3 are source-code compatible. Although version 1.3 contained a smaller set of changes than the preceding three major releases, it was nevertheless important.
The release of J2SE 1.4 further enhanced Java. This release contained several important upgrades, enhancements, and additions. For example, it added the new keyword assert, chained exceptions, and a channel-based I/O subsystem. It also made changes to the Collections Framework and the networking classes. In addition, numerous small changes were made throughout. Despite the significant number of new features, version 1.4 maintained nearly 100 percent source-code compatibility with prior versions.
The next release of Java was J2SE 5, and it was revolutionary. Unlike most of the previous Java upgrades, which offered important, but measured improvements, J2SE 5 fundamentally expanded the scope, power, and range of the language. To grasp the magnitude of the changes that J2SE 5 made to Java, consider the following list of its major new features:
• Generics
• Annotations
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• Autoboxing and auto-unboxing
• Enumerations
• Enhanced, for-each style for loop
• Variable-length arguments (varargs)
• Static import
• Formatted I/O
• Concurrency utilities
This is not a list of minor tweaks or incremental upgrades. Each item in the list represented a significant addition to the Java language. Some, such as generics, the enhanced for, and varargs, introduced new syntax elements. Others, such as autoboxing and auto-unboxing, altered the semantics of the language. Annotations added an entirely new dimension to programming. In all cases, the impact of these additions went beyond their direct effects. They changed the very character of Java itself.
The importance of these new features is reflected in the use of the version number "5." The next version number for Java would normally have been 1.5. However, the new features were so significant that a shift from 1.4 to 1.5 just didn't seem to express the magnitude of the change. Instead, Sun elected to increase the version number to 5 as a way of emphasizing that a major event was taking place. Thus, it was named J2SE 5, and the Developer's Kit was called JDK 5. However, in order to maintain consistency, Sun decided to use 1.5 as its internal version number, which is also referred to as the developer version number. The
"5" in J2SE 5 is called the product version number.
The next release of Java was called Java SE 6. Sun once again decided to change the name of the Java platform. First, notice that the "2" was dropped. Thus, the platform was now named Java SE, and the official product name was Java Platform, Standard Edition 6. The Java Developer's Kit was called JDK 6. As with J2SE 5, the 6 in Java SE 6 is the product version number. The internal, developer version number is 1.6.
Java SE 6 built on the base of J2SE 5, adding incremental improvements. Java SE 6 added no major features to the Java language proper, but it did enhance the API libraries, added several new packages, and offered improvements to the runtime. It also went through several updates during its (in Java terms) long life cycle, with several upgrades added along the way. In general, Java SE 6 served to further solidify the advances made by J2SE 5.
Java SE 7
The newest release of Java is called Java SE 7, with the Java Developer's Kit being called JDK 7, and an internal version number of 1.7. Java SE 7 is the first major release of Java since Sun Microsystems was acquired by Oracle (a process that began in April 2009 and that was completed in January 2010). Java SE 7 contains many new features, including significant additions to the language and the API libraries. Upgrades to the Java run-time system that support non-Java languages are also included, but it is the language and library additions that are of most interest to Java programmers.
The new language features were developed as part of Project Coin. The purpose of Project Coin was to identify a number of small changes to the Java language that would be incorporated into JDK 7. Although these new features are collectively referred to as "small," the effects of these changes are quite large in terms of the code they impact. In fact, for many programmers, these changes may well be the most important new features in Java
SE 7. Here is a list of the new language features:
• A String can now control a switch statement.
• Binary integer literals.
• Underscores in numeric literals.
• An expanded try statement, called try-with-resources, that supports automatic resource management. (For example, streams can now be closed automatically when they are no longer needed.)
• Type inference (via the diamond operator) when constructing a generic instance.
• Enhanced exception handling in which two or more exceptions can be caught by a single catch (multi-catch) and better type checking for exceptions that are rethrown.
• Although not a syntax change, the compiler warnings associated with some types of varargs methods have been improved, and you have more control over the warnings.
As you can see, even though the Project Coin features were considered small changes to the language, their benefits will be much larger than the qualifier "small" would suggest. In particular, the try-with-resources statement will profoundly affect the way that stream-based code is written. Also, the ability to now use a String to control a switch statement is a
long-desired improvement that will simplify coding in many situations.
Java SE 7 makes several additions to the Java API library. Two of the most important are the enhancements to the NIO Framework and the addition of the Fork/Join Framework. NIO (which originally stood for New I/O) was added to Java in version 1.4. However, the changes proposed for Java SE 7 fundamentally expand its capabilities. So significant are the changes, that the term NIO.2 is often used.
The Fork/Join Framework provides important support for parallel programming. Parallel programming is the name commonly given to the techniques that make effective use of computers that contain more than one processor, including multicore systems. The advantage that multicore environments offer is the prospect of significantly increased program performance. The Fork/Join Framework addresses parallel programming by
• Simplifying the creation and use of tasks that can execute concurrently
• Automatically making use of multiple processors
Therefore, by using the Fork/Join Framework, you can easily create scaleable applications that automatically take advantage of the processors available in the execution environment. Of course, not all algorithms lend themselves to parallelization, but for those that do, a significant improvement in execution speed can be obtained.
The material in this book has been updated to reflect Java SE 7, with many new features, updates, and additions indicated throughout.
A Culture of Innovation
Since the beginning, Java has been at the center of a culture of innovation. Its original release redefined programming for the Internet. The Java Virtual Machine (JVM) and bytecode changed the way we think about security and portability. The applet (and then the servlet) made the Web come alive. The Java Community Process (JCP) redefined the way that new ideas are assimilated into the language. Because Java is used for Android programming, Java is part of the smartphone revolution. The world of Java has never stood still for very long.
Java SE 7 is the latest release in Java's ongoing, dynamic history.
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