I’m trying to compile a fairly basic program under Linux and I’m having trouble with ld86. Anyone have an idea as to what auto_start is? UPDATE 3/12/2012: Seems to go away when I define my own printf()… Answer Huzzah! I have found it. When calling main() in main.c I was using parameters like this However, if I use no parameters…
How to automatically snapshot a volume of an Amazon EC2 instance?
I’m trying a script to backup a volume automatically. I follow this EBS-Snapshot.sh script as found on github: I have the two files for X509 authentication, the instance ID but I don’t understand the script and how to parameterise the volume that I want to backup. I don’t understand the first line (source) and the EC2_BIN. With that configuration, it
JAVA_HOME incorrectly set. How to reset it?
When I try to run mvn (Apache Maven, that is), I keep getting error “JAVA_HOME” not set. I follow the instructions to set the JAVA_HOME variable as follow; In the terminal: That looks correct, right? Then how come I still getting the incorrect JAVA_HOME error? Answer JAVA_HOME typically should only include the folder that contains the bin folder. So in
Tomcat 6 log4j – linux – safely remove catalina.out
Adding log4j [1] in tomcat 6.0.x forces tomcat to produce logs in “catalina” file. However, the default catalina.out is still produced and populated with logs. So, questions: Is it safe to delete catalina.out file (while server running)? If yes, could this deletion be added to tomcat startup script? If yes, could anyone please point out the file and the required
Find files and print only their parent directories
I have the following commands. Wherever the .user.log file is present, we need to print the parent directories (i.e hht and wee1.) How can this be done? Answer Am I missing something here. Surely all this regex and/or looping is not necessary, a one-liner will do the job. Also “for foo in $()” solutions will fail when there are spaces
rsync over SSH preserve ownership only for www-data owned files
I am using rsync to replicate a web folder structure from a local server to a remote server. Both servers are ubuntu linux. I use the following command, and it works well: The usernames for the local system and the remote system are different. From what I have read it may not be possible to preserve all file and folder
Linux readw and readl endianness
May anyone please explain the endianness of returned values by readw and readl. I am currently using PowerPC arch. Thanks and Best Regards! Answer “readw” and “readl” return the value of the underlying architecture. As it happens, a PowerPC can be either big- or little endian. AFAIK, most Linux implementations run PPC in big-endian mode.
What are the disadvantages of Linux’s message queues?
I am working on a message queue used to communication among process on embedded Linux. I am wondering why I’m not using the message queues provided by Linux as following: msgctl, msgget msgrcv, msgsnd. instead of creating shared memory, and sync up with semaphore? What’s the disadvantage of using this set of functions directly on a business embedded product? Answer
Use grep to match a pattern in a line only once
I have this: Which gives this: I understand whats happening. How do I stop grep from trying to continue matching after 1 successful match? How do I get only Answer You need to do the grouping: (…) followed by the exact number of occurrence: {<n>} to do the job: Hope it helps. Cheers!!
httpd: Could not reliably determine the server’s fully qualified domain name, using 127.0.0.1 for ServerName
I tried to restart my Apache server on CentOS 5.0 and got this message: httpd: Could not reliably determine the server’s fully qualified domain name, using 127.0.0.1 for ServerName Here is the /etc/hosts file: Here is the /etc/sysconfig/network file: I also have this in the Apache httpd.conf file: However, I still get the first error message when I restart Apache.