In Emacs, how to print the name of the current file that I am editing? The built-in function buffer-file-name gives the full path of your file. To get the file name: M-: buffer-file-name
How to compress lists of consecutive citation numbers to one number range in Latex? For example, change [14], [15], [16], [17], [19] to [14-17], [19] That will save some space for the paper/document written in latex. The cite package is great from my experience. You just need to add usepackage{cite} in the document’s preamble and…
How to get a tree-like view of the git commit history? My favorite command line: git log –graph –oneline It will prints a text based graph like (with colors): * b5dc8b9 Merge branch ‘master’ of https://github.com/layerzero/libi0 | | * 7514ef1 revised the README.md a little bit | * 6692428 align size to page for both…
How to exclude users from appearing in the GDM login screen of Gnome 3? There is a long-time bug related to this ( https://bugzilla.redhat.com/show_bug.cgi?id=723708 ) which causes that the /etc/gdm/custom.conf has no effect. The closes workaround I find working on Fedora 20 is to totally disable listing of users (run as root): cat > /etc/dconf/db/gdm.d/01-mysettings…
Chrome caches redirects. How to flush a cached redirect by Chrome? Clearing the cache/cookies for the specific domain (sorry, it is the domain level in this solution) as in https://www.systutorials.com/qa/453/how-to-remove-cookies-for-a-certain-site-in-chrome will also flush the redirect caches for this domain.
On Linux, how to download a webpage as a mobile browser? You can change the agent of curl to be a mobile browser’s and the remote webserver may be consider the request from a mobile browser: curl -A “Mozilla/5.0 (iPhone; CPU iPhone OS 6_1_3 like Mac OS X) AppleWebKit/536.26 (KHTML, like Gecko) CriOS/28.0.1500.12 Mobile/10B329 Safari/8536.25″…
How to allow pre tag in WordPress comments? You can add a filter hook for pre_comment_approved: <?php function filter_handler( $approved , $commentdata ) { // inspect $commentdata to determine approval, disapproval, or spam status return $approved; } add_filter( ‘pre_comment_approved’ , ‘filter_handler’ , ’99’, 2 ); ?> Reference: https://codex.wordpress.org/Plugin_API/Filter_Reference/pre_comment_approved
crond sends email notifications automatically. However, these emails are not needed. How to disabled it? If your command does not anything printed to STDOUT or STDERR, there is not emails send. You can redirect 2 and 1 to /dev/null at the end of your command. You can also set the MAILTO variable to empty by…
What are all the bash supported comparison operators? The man 1 test contains all the operators supported in bash. An omitted EXPRESSION defaults to false. Otherwise, EXPRESSION is true or false and sets exit status. It is one of: ( EXPRESSION ) EXPRESSION is true ! EXPRESSION EXPRESSION is false EXPRESSION1 -a EXPRESSION2 both EXPRESSION1…
How to generating TAGS file for Emacs recursively? etags seems not support recursively generating TAGS file. I use ctags instead. It can also generate TAGS file for Emacs with the -e option: ctags -e -R . You can also use etags with find: find ./ -print | xargs etags But I prefer the ctags way.
How to aggregate multiple RSS feeds to a single one? If you want a program to construct a web service by your own, SimplePie may be a good choice. It is written in PHP. If you just want a tool to make work done, I suggest Yahoo Pipes which works really well for me. (Yahoo…
How to view the DVI files generated by latex on Linux? It seems evinece can not open it. After install the evince-dvi package, evince should be able to view dvi files: # yum install evince-dvi
How to find which files are opened by a Linux program? For example, when I run cat ~/.bashrc, how to find out which files are opened by cat? You can achieve this by using strace if the program “open” files using system calls. For example, I run as this: strace -o /tmp/st cat ./.bashrc grep…
How to generate reference of web pages in the IEEE citation format with bibtex? From the IEEE Citation Reference, the reference for web page is like this: WWW Basic Format: [1] J. K. Author. (year, month day). Title (edition) [Type of medium]. Available: http://www.(URL) Example: [1] J. Jones. (1991, May 10). Networks (2nd ed.) [Online]….
I am using Fedora 20. I installed the rpm from Oracle for the Oracle JDK. How to set up the environment so that the Java environment is Oracle JDK instead of the OpenJDK? The Oracle JDK is install to /usr/java/ directory. On my Fedora 20, it looks like this: $ ls /usr/java -l total 4…
What is the maximum size of objects that I can store on Amazon S3? Now (Apr. of 2014), the limitation is 4TB. Before, Dec. 2010, it was 5GB. Reference: http://aws.typepad.com/aws/2010/12/amazon-s3-object-size-limit.html But be aware that the 10,000 part limit still applies.
How to set the data replication factor of Hadoop HDFS in Hadoop 2 (YARN)? The default replication factor in HDFS is controlled by the dfs.replication property. The value is 3 by default. To change the replication factor, you can add a dfs.replication property settings in the hdfs-site.xml configuration file of Hadoop: <property> <name>dfs.replication</name> <value>1</value> <description>Replication…
How to balance the two columns of text on the last page of a Latex doc? 2 good Latex packages are good at balancing the two columns of text on the last page of a Latex doc (choose either one that are good for you). balance Usage: At the beginning of the doc: usepackage{balance} At…
How to improve MPlayer video quality by selecting a “better” video rendering/filter? You can choose a different video filter. I use hqdn3d which gives me the best quality. Be careful on machines with low CPUs. To use hqdn3d, put this line into your ~/.mplayer/config: vf=hqdn3d Check more options of video filters in MPlayer manual.
How to force MPlayer to start a video at the center of the screen? I assume you are using Linux. Put this line into your ~/.mplayer/config: geometry=50%:50% Check more options in MPlayer manual.