As we know: There is no goto statement support in bash. goto is useful for certain situations, especially for debugging. So, is there any alternative mechanisms to goto in bash? Robert Copeland gave an interesting hacking to this problem: http://bobcopeland.com/blog/2012/10/goto-in-bash/ The idea is like the self-modifying code. But the difference is to generate a piece…
I have several installation of Thunderbird under Linux to check/send emails using IMAP email servers. I use filters extensively to manage my emails. How to export and import message filters of Thunderbird so that I can synchronize the rules on several installations? About message filters in Thunderbird (More at http://kb.mozillazine.org/Filters_(Thunderbird)): Filters are account specific, there…
I use Emacs in console. The linum-mode displays the line numbers just well. However, in the console, there is no space between the line numbers and the text content, which makes it a little messy some times. How to add a space between the line numbers and text content in Emacs? If you are using…
How to make xterm display Chinese characters? It just displays some small rectangles for Chinese characters. First, the settings for some old X programs like xterm is in ~/.Xresources. And it takes effect after the X server restarts, or you can manually load the settings by xrdb -merge ~/.Xresources Second, the Chinese or similar fonts…
I use Emacs in consoles and start Emacs frequently (like check a file, edit it, close it and loop). However, Emacs seems take some time to start up especially some modes/extensions are used. How to make Emacs start up faster? I summarize my solution at this post: Making Emacs Startup Faster. The key is to…
I have a large IMAP email account which contains many emails in a rich structure of directories. How to back up the whole IMAP account to my local computer? The requirements: Automatically downloading these files. There are many directories, and copying-pasting emails will take too much time. Keep the directory structures which are used to…
In sbt, I found this message printed out by the scala compiler: [warn] there were 1 deprecation warning(s); re-run with -deprecation for details [warn] one warning found The question is, how to add options (-deprecation here) to the scala compiler in sbt? You can use this inside the sbt console: set scalacOptions += “-deprecation”
On Linux, a default editor is used for text editing such as crontab -e or git commit. How to change it to the editor of my own choice? The default editor is indicated by the EDITOR environment variable. You can set this environment variable to set the default editor. For example, set it to emacs…
We have many hosts with internal IPs like 10.0.3.* behind a gateway, say gateway.example.org. The hosts with internal IP connect to the Internet through the gateway. How to directly SSH to hosts using internal IPs through the gateway? Here is the solution: Directly SSH to Hosts with LAN IPs Through the Gateway
Is is possible to cut in Linux using a string as the delimiter? cut –delimiter=”delim” -f 1,3 cut reports: cut: the delimiter must be a single character The most closest solution that I find is using awk/gawk: awk -F ‘delim’ ‘{print $1; print $3}’ From the manual: -F fs –field-separator fs Use fs for the…
Any good programming language popularity indices? Those are interesting ones: TIOBE Indexhttp://www.tiobe.com/index.php/content/paperinfo/tpci/index.html The RedMonk Programming Language Rankings: January 2014 This ranking is published as blog posts. So no persistent homepage found yet. The January 2014 version is: http://redmonk.com/sogrady/2014/01/22/language-rankings-1-14/ Programming Language Popularityhttp://langpop.com/
I am tired of the non-efficient “Print Screen” -> Paste in Paint -> Save way. How to efficiently take screenshot on Windows 7? On Windows 7 and later ones, the “Snipping Tool” is handy. Press the “Win” key and input “snipping tool”. The tool will appear in the menu. You can select the whole window,…
I share a ADSL modem via a Wifi router with several roommates. Sometimes, I find the network bandwidth left is too little. Suspiciously, some one is using BT, Thunder, eMule or other P2P tools. These tools can easily use up all the bandwidth and left little for others. How to prevent some roommates from hogging…
I had a TP-Link TL-WN725N v2 USB wireless adapter. But it seems the kernels in Fedora 19 have not yet included drivers for it. How to install drivers for TL-WN725N v2 on Fedora 19? The driver is under development. You can find the source here and in the drivers/staging in the Linux kernel. If you…
The AddThis welcome bar will make a empty gap on top of the WordPress webpage with the TwentyFourteen wordpress theme. Is there a fix for it? You will find AddThis will add this div to the webpage: <div class=”addthis_bar_placeholder” style=”height: 46px;”></div> which cause the problem. A little trick that works is to set that div’s…
I use the AddThis share buttons on my sites. How to add the via @fclosedotcom to the Tweet button of AddThis share so that the tweets automatically @ my twitter handle? Change <a class=”addthis_button_tweet”></a> to <a class=”addthis_button_tweet” tw_via=”fclosedotcom”></a> Try it on this page with the Tweet button.
I experience this problem: I have a file common.mk that includes release.mk which in the same directory. common.mk is included by the top-level Makefile. common.mk and release.mk are shared by multiple projects and the top-level Makefile may stay in different directories with {common,release}.mk. Now, include in make use the pwd as base directory. So, simply…
I have multiple video files, say video1.avi, video2.avi and video3.avi. How to concatenate these multiple video file to a single file together on Linux? You can use mencoder to concatenate multiple video files to one file. For installing mencoder on Fedora, please check: http://www.systutorials.com/1493/mplayer-on-fedora/ For the question, the command is: mencoder -oac copy -ovc copy…
I have many files in a directory on Linux. How to find top K largest files in a directory? For example, find top 10 (K=10) large files in the current directory: du -h –max-depth 1 * | sort -rh | head -n 10
I have many files under a directory. How to find those files under the directory that are larger than certain size, say 500MB? Find the files that are larger than 500MB in the current directory (./): find ./ -size +500M Prints our more information about these files: find ./ -size +500M -exec ls -lh {}…