blogd − boot logging on /dev/console
/sbin/blogd [/dev/realtty]
Without argument blogd determines the real underlying character device of /dev/console. blogd spawns a pty/tty pair to reconnect the current /dev/console with the slave of the pty/tty pair. During writing information from this slave to the real character device a ring buffer is used to hold the information for writing it to an existing logging file.
To fetch the real tty of /dev/console the program showconsole(8) can be used. This has the advantage that blogd will not hold the real character device of /dev/console as its controlling tty (would hangup any running getty on that character device).
blogd
knows a few signal to contol its behavior.
SIGQUIT, SIGINT, and SIGTERM
will cause blogd tries to write out the ring buffer and to exit.
SIGIO |
says blogd that now it is able to write on /var/log/boot.msg which means that the file system is mounted read/write and the kernel messages are written to that file. | ||
SIGSYS |
says blogd that it should stop writing to disk but continue to repeat messages to the old devices of the system console. |
blogd needs a mounted /proc and /dev/pts file system and tries to set the controlling tty to stdin if the real character device of /dev/console is not given. After reading /proc blogd tries to restore the status of the controlling tty to avoid problems with getty processes. This can fail because blogd forks to run in the background as a daemon.
/proc/<pid of blogd>/stat
the stat file of the blogd process.
/dev/console
the system console.
/var/log/boot.msg
logging file which is created by klogd(8) or dmesg(8).
showconsole(8), syslogd(8), klogd(8), dmesg(8), proc(5).
2000 Werner Fink, 2000 SuSE GmbH Nuernberg, Germany.
Werner Fink <werner@suse.de>
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.