Saturday, February 27, 2010
Wednesday, February 24, 2010
The Outer Limits episode 1: The Galaxy Being
Thanks to a good friend of mine, I recently discovered B-Movie Cast, a weekly podcast that discusses B-movies, cult moves and many more nerd stuffs. The podcast itself is really neat. In each episode the host Vince Rotolo together with his co-host Nic "BMovieMan" present a movie, they review it with lots of details and sometimes gossip about the production, all in a relaxed way. Ample space is then left to the contributes from the listeners. Emails are read and voice messages are listened to. The hosts are very competent and for each contribute they have comments or answers to questions.
I’ve always appreciated B-Movies especially those of the Hollywood golden age and later movies of the sixties and seventies. However I can’t say that I there was really a passion for that stuff, the fondness was latent, it needed something to dig it out and expose it to consciousness. I timidly begun to listen to B-Movie cast but the familiar attitude and the soft tone of the speakers plus the richness of the exposition immediately took me. With every episode the guys at B-Movie cast select and present movies and shows which usually date somewhere from the fifties to the seventies. This is a perfect system for a neophyte like me to discover films which are not only fun but are like a window opened on a world of the past with all its different culture conventions, fashion and technology.
In episode nr. BMC90 of February 18th 2010, the show presented the first installment of a series of episodes on the America tv series The Outer Limits which aired from 1963 to 1965. The series is all about the confrontation of men with the mysteries that invade the space of the normality and rip it apart.
The series opening is somehow mythical. The picture of an oscilloscope appears and immediately the cold voice of a narrator states:
There is nothing wrong with your television set. Do not attempt to adjust the picture. We are controlling transmission. If we wish to make it louder, we will bring up the volume. If we wish to make it softer, we will tune it to a whisper. We will control the horizontal. We will control the vertical. We can roll the image, make it flutter. We can change the focus to a soft blur or sharpen it to crystal clarity. For the next hour, sit quietly and we will control all that you see and hear. We repeat: there is nothing wrong with your television set. You are about to participate in a great adventure. You are about to experience the awe and mystery which reaches from the inner mind to... The Outer Limits.
As I’m already a tv series addict, this episode of B-Movie Cast prompted me to acquire the series. By now I only watched the first episode “The Galaxy Being” which is about a SETI style wannabe researcher who make contact with an alien species which is then summoned to our planet by the negligence of a secondary character. I advise you to listen to the episode of B-Movie Cast for more information about the plot.
I was really amazed by the general appeal of this series. Despite the fact it was obvious it was fifty years old, I found the narration and the character definition really modern. I mean, the characters felt real, and the tension of simple human beings forced to confront something so unnatural to them , was nearly palpable. The fact that the being arrived to our world during the night, the constant presence of static noise, the close-ups of the being prowling the city, enforced the sensation of an obscure force distressing the human minds. Despite from the beginning of the episode it’s clear to the viewer that the being isn’t evil, its very presence on the earth generates a sensation of madness that wobbles through the people. Only in the end –which I’ll not discuss it- the humans can glimpse hope of if not comprehension, acceptation of something so alien to them.
The special effects aren't really bad considering the period of time and the fact that it was a television product. The costume of the being is very convincing in showing it a creature of electronic power. I can say the same regarding the effect of the radiation boom.
If you like tv series and if you don’t necessarily despise old shows, I really advice you to watch The Outer Limits because it’s really promising. I plan to watch other episodes very soon and I will report about them in this blog.
Be also sure to check B-Movie Cast at http://bmoviecast.com/
I’ve always appreciated B-Movies especially those of the Hollywood golden age and later movies of the sixties and seventies. However I can’t say that I there was really a passion for that stuff, the fondness was latent, it needed something to dig it out and expose it to consciousness. I timidly begun to listen to B-Movie cast but the familiar attitude and the soft tone of the speakers plus the richness of the exposition immediately took me. With every episode the guys at B-Movie cast select and present movies and shows which usually date somewhere from the fifties to the seventies. This is a perfect system for a neophyte like me to discover films which are not only fun but are like a window opened on a world of the past with all its different culture conventions, fashion and technology.
In episode nr. BMC90 of February 18th 2010, the show presented the first installment of a series of episodes on the America tv series The Outer Limits which aired from 1963 to 1965. The series is all about the confrontation of men with the mysteries that invade the space of the normality and rip it apart.
The series opening is somehow mythical. The picture of an oscilloscope appears and immediately the cold voice of a narrator states:
There is nothing wrong with your television set. Do not attempt to adjust the picture. We are controlling transmission. If we wish to make it louder, we will bring up the volume. If we wish to make it softer, we will tune it to a whisper. We will control the horizontal. We will control the vertical. We can roll the image, make it flutter. We can change the focus to a soft blur or sharpen it to crystal clarity. For the next hour, sit quietly and we will control all that you see and hear. We repeat: there is nothing wrong with your television set. You are about to participate in a great adventure. You are about to experience the awe and mystery which reaches from the inner mind to... The Outer Limits.As I’m already a tv series addict, this episode of B-Movie Cast prompted me to acquire the series. By now I only watched the first episode “The Galaxy Being” which is about a SETI style wannabe researcher who make contact with an alien species which is then summoned to our planet by the negligence of a secondary character. I advise you to listen to the episode of B-Movie Cast for more information about the plot.
The special effects aren't really bad considering the period of time and the fact that it was a television product. The costume of the being is very convincing in showing it a creature of electronic power. I can say the same regarding the effect of the radiation boom.
If you like tv series and if you don’t necessarily despise old shows, I really advice you to watch The Outer Limits because it’s really promising. I plan to watch other episodes very soon and I will report about them in this blog.
Be also sure to check B-Movie Cast at http://bmoviecast.com/
Monday, February 22, 2010
Log system in Linux
The Linux operating system is said to be highly manegeable, customizable and safe. One of the reason behind this concept is the logging system.
The scope of logging is to record all what happen to the various part of the running operating system into plain text files that can be then read by humans or parsed by machines.
Understanding and referring to the various logs is an invaluable resource for trouble shooting and, more important, keeping the reins of your computer.
Linux logs are located in the /var/log directory and are plain ASCII files that can be handled virtually by any text reader out there. The majority of logs are created by syslogd and klogd daemons while installed programs (like SAMBA) can create their specific logs.
syslogd deamon deals with system messages and other messages like those coming from applications. However Kernel messages can’t use the syslog API. klogd manages messages coming from the kernel itself. Both of them can have their behavior configured by the parameters contained respectively in the files /etc/syslog.conf and /etc/sysconfig/syslog and, for klogd through a series of switches and commands in the console. The configuration of these can be tricky and it’s a subject which needs a full long article to be covered. However, in general, by configuring /etc/syslog.conf one can control the messages flow and specify custom reception points for various class of messages. For a example a powerful security procedure could be to relay critical messages from the kernel to an external host which will in turn manage those messages according to its syslogd policy. This way would prevent a possible attacker from covering its tracks by deleting parts in the logs. A further improvement could also be to write a script to parse the two versions of the same logs (locally and remote) to check for discrepancies (sign of possible breaks). If you’re eager to delve a bit more into syslogd and its configuration you can have a look to the manual pages in bash (man syslogd and man syslogd.conf).
As I said above there are mainly two groups of logs: system logs and application logs.
As the name suggests, system logs concern themselves with the operating system functioning. Let’s see the most important ones.
Messages Log (/var/log/messages)
This log is a crucial one because it records status messages from the running system. General system errors like those related to I/O and networking are written to the messages log, as well as other interesting messages like users becoming root, running services, etc. In case of trouble shooting this could be the first place to get information before delving into more specific logs.
Authorization Log (/var/log/auth.log) This log keep track of all the systems which deal with authorizing users to restricted access to files or functions. By reading this log you can see things like the user login and usage of sudo to gain super user authorizations, and remote logins via ssh.
Daemon Log (/var/log/daemon.log)This log records information regarding daemons running on the system. A daemon, or service, is a program which is not under direct control of a user but instead runs in background to perform certain tasks.
Debug Log (/var/log/debug)
Read this log to check debug messages from the operating system and applications
Kernel Log (/var/log/kern.log)
This log contains messages concerning the Linux kernel which are routed via klogd daemon. These messages are very interesting for example because they’re helpful for trouble shooting but also to analyze them for kernel tuning or customization.
Applications logs
Some installed applications can provide their specific logs. These are usually stored at /var/log followed by the application sub directory. An example is the X11 server log which contains the messages coming from the X11 Windowing Server. If you experience crashes or problems with X, have a look to this log to see error messages.
As I mentioned before, certain logs are not normally meant for humans to read them but machines. For example, and always located under var/log/, wtmp log shows the information regarding the user(s) logged into the system, failog log displays login failures and lastlog records the logins in a list.
Sometimes you will notice log files, within the /log/ folder, ending with something like ‘.0,.1, .2, and so on’ and ‘.gz’. This has to do with the concept of rotation. The logrotate command is in charge of renaming on log file at a certain point in time, and start a new log. This is of course to rationalize the log process and avoid having logs which are heavy and difficult to interpret. After all the log concept is like that of a diary and so it’s perfectly sensible to split it on a time basis. So, logrotate will first put numbers to the end of the log file according to its age (lower numbers mean older logs) and then, after more time, bundle a number of files and compress them for example with gzip. The logrotate.conf file configures the logrotate behavior. If you want to do so you can read more information on the manual with man logrotate.
Now that we have said some things about the logging system and the logs, let’s spend some words about the tools which helps viewing the content of the log.
As we said at the beginning, logs are files containing standard ASCII information, thus any program capable of displaying text is good. You can use any word processor program, your favorite internet browser or a programming language IDE.
Anyway, it’s sometimes quicker to read the logs within the console. Here below a list of some useful commands to perform this task. For a complete overview and an explanation of the various switches and options for each program please refer to the manual typing man followed by the program name in the console.
More
Use the program more to display the content of one log one page at a time – more /var/log/messages
Less
less is a console pager program similar to more but with the additional capability of navigate the pages forward and backward. It’s also faster because it doesn’t load all the file at one time.
- less /var/log/daemon.log
Tail
This console program is quite interesting because by displaying the last 10 lines of a document it enables the user to keep track of the new records in real time. For example with the command tail /var/log/messages you will see a static list of the last ten entries in the log, but by adding the –f switch, thus tail –f /var/log/messages the list will update in real time each time a new entry is recorded into the log.
Grep
The grep command is designed to search a log file, which is very useful if you must quickly locate certain entries in a large log. For example you can search the “kern” word in a log by typing grep “kern” syslog.conf. If the entries are a lot, you can use | to pipe them through less thus having them paged. To to this type grep “kern” syslog.conf | less
I think that by now you have a simple (a by any means not exhaustive) overview of the logging system on Linux. I personally think that given the importance the information technology have in our lives nowadays, it’s really a valuable effort to delve a bit into the functioning of the machines we use to carry on our job activities and, with more and more frequency and permeation, various aspect of our social life. Linux operating system, throughout all its ecosystem of distributions, gives a hand to the users providing them with all the instruments to use their computer on an informed basis.
Live long and prosper.
Image by zak_greant licensed with this license
Understanding and referring to the various logs is an invaluable resource for trouble shooting and, more important, keeping the reins of your computer.
Linux logs are located in the /var/log directory and are plain ASCII files that can be handled virtually by any text reader out there. The majority of logs are created by syslogd and klogd daemons while installed programs (like SAMBA) can create their specific logs.
syslogd deamon deals with system messages and other messages like those coming from applications. However Kernel messages can’t use the syslog API. klogd manages messages coming from the kernel itself. Both of them can have their behavior configured by the parameters contained respectively in the files /etc/syslog.conf and /etc/sysconfig/syslog and, for klogd through a series of switches and commands in the console. The configuration of these can be tricky and it’s a subject which needs a full long article to be covered. However, in general, by configuring /etc/syslog.conf one can control the messages flow and specify custom reception points for various class of messages. For a example a powerful security procedure could be to relay critical messages from the kernel to an external host which will in turn manage those messages according to its syslogd policy. This way would prevent a possible attacker from covering its tracks by deleting parts in the logs. A further improvement could also be to write a script to parse the two versions of the same logs (locally and remote) to check for discrepancies (sign of possible breaks). If you’re eager to delve a bit more into syslogd and its configuration you can have a look to the manual pages in bash (man syslogd and man syslogd.conf).
As I said above there are mainly two groups of logs: system logs and application logs.
As the name suggests, system logs concern themselves with the operating system functioning. Let’s see the most important ones.
Messages Log (/var/log/messages)
This log is a crucial one because it records status messages from the running system. General system errors like those related to I/O and networking are written to the messages log, as well as other interesting messages like users becoming root, running services, etc. In case of trouble shooting this could be the first place to get information before delving into more specific logs.
Authorization Log (/var/log/auth.log) This log keep track of all the systems which deal with authorizing users to restricted access to files or functions. By reading this log you can see things like the user login and usage of sudo to gain super user authorizations, and remote logins via ssh.
Daemon Log (/var/log/daemon.log)This log records information regarding daemons running on the system. A daemon, or service, is a program which is not under direct control of a user but instead runs in background to perform certain tasks.
Debug Log (/var/log/debug)
Read this log to check debug messages from the operating system and applications
Kernel Log (/var/log/kern.log)
This log contains messages concerning the Linux kernel which are routed via klogd daemon. These messages are very interesting for example because they’re helpful for trouble shooting but also to analyze them for kernel tuning or customization.
Applications logs
Some installed applications can provide their specific logs. These are usually stored at /var/log followed by the application sub directory. An example is the X11 server log which contains the messages coming from the X11 Windowing Server. If you experience crashes or problems with X, have a look to this log to see error messages.
As I mentioned before, certain logs are not normally meant for humans to read them but machines. For example, and always located under var/log/, wtmp log shows the information regarding the user(s) logged into the system, failog log displays login failures and lastlog records the logins in a list.
Sometimes you will notice log files, within the /log/ folder, ending with something like ‘.0,.1, .2, and so on’ and ‘.gz’. This has to do with the concept of rotation. The logrotate command is in charge of renaming on log file at a certain point in time, and start a new log. This is of course to rationalize the log process and avoid having logs which are heavy and difficult to interpret. After all the log concept is like that of a diary and so it’s perfectly sensible to split it on a time basis. So, logrotate will first put numbers to the end of the log file according to its age (lower numbers mean older logs) and then, after more time, bundle a number of files and compress them for example with gzip. The logrotate.conf file configures the logrotate behavior. If you want to do so you can read more information on the manual with man logrotate.
Now that we have said some things about the logging system and the logs, let’s spend some words about the tools which helps viewing the content of the log.
As we said at the beginning, logs are files containing standard ASCII information, thus any program capable of displaying text is good. You can use any word processor program, your favorite internet browser or a programming language IDE.
Anyway, it’s sometimes quicker to read the logs within the console. Here below a list of some useful commands to perform this task. For a complete overview and an explanation of the various switches and options for each program please refer to the manual typing man followed by the program name in the console.
More
Use the program more to display the content of one log one page at a time – more /var/log/messages
Less
less is a console pager program similar to more but with the additional capability of navigate the pages forward and backward. It’s also faster because it doesn’t load all the file at one time.
- less /var/log/daemon.log
Tail
This console program is quite interesting because by displaying the last 10 lines of a document it enables the user to keep track of the new records in real time. For example with the command tail /var/log/messages you will see a static list of the last ten entries in the log, but by adding the –f switch, thus tail –f /var/log/messages the list will update in real time each time a new entry is recorded into the log.
Grep
The grep command is designed to search a log file, which is very useful if you must quickly locate certain entries in a large log. For example you can search the “kern” word in a log by typing grep “kern” syslog.conf. If the entries are a lot, you can use | to pipe them through less thus having them paged. To to this type grep “kern” syslog.conf | less
I think that by now you have a simple (a by any means not exhaustive) overview of the logging system on Linux. I personally think that given the importance the information technology have in our lives nowadays, it’s really a valuable effort to delve a bit into the functioning of the machines we use to carry on our job activities and, with more and more frequency and permeation, various aspect of our social life. Linux operating system, throughout all its ecosystem of distributions, gives a hand to the users providing them with all the instruments to use their computer on an informed basis.
Live long and prosper.
Image by zak_greant licensed with this license
Wednesday, February 17, 2010
Wiz and Chips is back
Wiz and Chips is back.
Hello everybody, after some months of stop, the blog is on track again with a new domain name.
My friend King Felix was so kind to withstand the untamed flow of lunatic requests and designed for me a brand new layout.
The atmosphere here got darker with a flavor of vintage horror and machinery.
Let me know what you think about it.
live long and prosper
Hello everybody, after some months of stop, the blog is on track again with a new domain name.
My friend King Felix was so kind to withstand the untamed flow of lunatic requests and designed for me a brand new layout.
The atmosphere here got darker with a flavor of vintage horror and machinery.
Let me know what you think about it.
live long and prosper
HiRISE: web 2.0 in space exploration
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HiRISE stands for the High-Resolution Imaging Science Experiment which is on board the Mars Reconnaissance Orbiter launched by NASA in 2005 to investigate specifically in the long term presence of water on Mars.
HiRISE project is already providing a wide collection of 11758 (at present) stunning photographic material available in several high resolution formats to the public, including a catalogue of Anaglyphs for the observation in 3D relief of the Martian surface. The HiRISE camera is the most powerful ever sent to another planet and with a resolution of 30 cm/pixel allows us to see images of Mars with an unprecedented level of detail.
HiWish is a new, smart and fun way to be part to the exploration of the red planet. It’s basically a system through which you can submit a suggestion to the experiment for an area of the Mars surface to be photographed by the spacecraft camera. The selection is very straight forward and allows to user to specify a location by selecting it on a Mars Google Maps gadget. Other more specific information regarding the location, as well as the scientific field of interest for the image, can be submitted by other tools present in the page.
I can’t do anything but praising this operation which is another example of the so-called web 2.0 can be used as a powerful educational tool. If you stop for a second and think about it, it’s really astonishing how our generation is given access to such incredible opportunities to take part of space exploration directly from the comfort of our homes.
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