How to make ctags recognize specific files with certain extensions such as .c0 or .puc as C source files? You may add this line to your ~/.ctags: –langmap=c:+.c0,c:+.puc
How to make taglist recognize specific files with certain extensions as C source files? You may try adding this line to your ~/.vimrc: autocmd BufRead,BufNewFile *.c0 set filetype=c Reference: https://stackoverflow.com/questions/9013263/vim-tagslist-plugin-not-detecting-custom-language-racket
We may need to maintain a dev-name branch on git remote server to share your codes. How to create the branch? 1, git checkout -b your_branch_name 2, Do your changes, add commit 3, git push origin your_branch_name References:http://stackoverflow.com/questions/1519006/how-do-you-create-a-remote-git-branch
I want to kick off a user such as “bob” on a Linux box which I managed remotely. How to do this? bob may log on the Linux box by various ways: Log on the screen on the Linux box (locally) with a X server. Log on remotely by a ssh shell. Log on by…
How can I force iPhone to reboot/restart/reset when it locks up completely and does not response? To force an iPhone to restart: Press and hold the iPhone’s power key and home button together. Holding the two keys for around 10~15 seconds until the screen is turned off. Release the buttons once the screen lights up…
Resizing images on Linux with gThumb is easy. However, I have a batch of images inside a folder. Manually resizing them will consume too much time. How to automatically resize them on Linux with a script? You can use convert from ImageMagick together with bash script to resize images inside a directory. mkdir resize; IFS=$(echo…
The “Entering/Leaving…” messages when invoking another make by a make is kind of annoying. Is it possible to suppress these messages and how to suppress them? For GNU make, it is controlled by options: -w, –print-directory Print a message containing the working directory before and after other processing. This may be useful for tracking down…
We have a running HDFS cluster. Currently, the NameNode metadata data directory has only one directory configured in hdfs-site.xml: <property> <name>dfs.namenode.name.dir</name> <value>file:///home/hadoop/hdfs/</value> <description>NameNode directory for namespace and transaction logs storage.</description> </property> We would like to add a new directory for dfs.namenode.name.dir to make replicas of the metadata on a separated disk for higher data reliability….
If you encounter an error message like the one below when attempting to SSH to a server: @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that a host key has…
I noticed that some guys’ screen console has a status bar with tab numbers. That will be very useful for 1) know you are using screen rather than a normal terminal. 2) which tab you are working in. Below is my ~/.screenrc: hardstatus alwayslastline hardstatus string ‘%{= kG}[ %{G}%H %{g}][%= %{=kw}%?%-Lw%?%{r}(%{W}%n*%f%t%?(%u)%?%{r})%{w}%?%+Lw%?%?%= %{g}][%{B}%Y-%m-%d %{W}%c %{g}]’ It…
How to detect whether a .jpg image is almost blank/black on Linux? Here is a bash function that I used to detect whether an image is black on Linux: function isBlank () { mean=`convert $1 -format “%[mean]” info:` echo “$mean” } It uses ImageMagic to generate formatted image characteristics (the mean). If the mean is…
A related question: how to find the replication factors of files in a HDFS cluster? method 1: You can use the HDFS command line to ls the file. The second column of the output will show the replication factor of the file. For example, $ hdfs dfs -ls /usr/GroupStorage/data1/out.txt -rw-r–r– 3 hadoop zma 11906625598 2014-10-22…
How to list all files from a .deb package like rpm -ql on RPM based systems? Use this command dpkg -L pkg_name -L lists files: -L, –listfiles package-name… List files installed to your system from package-name. More on the dpkg command, check dpkg manual.
I have multiple jpg images as files like 001.jpg, 002.jpg … How to merge multiple jpg images to a pdf on Linux? convert is your good friend: convert *.jpg output.pdf
How to remove .svn directories under hlfs dir recursively as follows. weiwei@weiwei-HP-Compaq-dx6128-MT-PX478AV:~/workshop1/hlfs > find ./ -name “.svn” ./test/build/.svn ./test/.svn ./output/conf/.svn ./output/lib32/.svn ./patches/.svn ./src/include/.svn ./src/include/api/.svn ./src/snapshot/.svn ./src/snapshot/unittest/build/.svn ./src/snapshot/unittest/.svn ./src/utils/.svn ./src/clean/Mapreducer/build/.svn ./src/clean/Mapreducer/.svn ./src/clean/.svn ./src/clean/unittest/.svn ./src/icache/.svn ./src/icache/unittest/.svn ./src/backend/.svn ./src/storage/.svn ./src/cache/.svn ./src/cache/unittest/.svn ./src/clone/.svn ./src/tools/.svn ./src/tools/unittest/.svn ./src/logger/.svn weiwei@weiwei-HP-Compaq-dx6128-MT-PX478AV:~/workshop1/hlfs > find ./ -name “.svn” | xargs rm -rf
How to download a rtmp video stream on Linux? You can use mplayer to dump the rtmp stream like: mplayer -dumpstream rtmp://example.com/path/to/stream.mp4 It will generate ./stream.dump and you can rename it to the file with the extension you need like stream.mp4. The rtmp link usually can be found from the HTML or JavaScript source code…
Now, I have a running HDFS cluster storing lost files. I want to change its default replication factor. How to change it? What will happen after it is changed? For example, I change from 2 to 3. Will HDFS automatically re-replicate the data chunks? First, the replication factor is client decided. Second, the replication factor…
How to install latest version of Calibre? The version from my distro (Ubuntu, Linux Mint, Fedora) seem at 1.xx while the latest Calibre is already at 2.x. You may check Caibre website’s instruction: http://calibre-ebook.com/download_linux sudo -v && wget -nv -O- https://raw.githubusercontent.com/kovidgoyal/calibre/master/setup/linux-installer.py | sudo python -c “import sys; main=lambda:sys.stderr.write(‘Download failedn’); exec(sys.stdin.read()); main()”
How to install gitbook on my own Linux box? First, install node.js following https://www.systutorials.com/qa/1268/how-to-install-node-js-on-fedora or How to install node.js on Ubuntu/Linux Mint depending on your distro. Second, install gitbook by npm to /opt/: # cd /opt/ # npm install gitbook Then, the gitbook can be invoked by /opt/node_modules/gitbook/bin/gitbook.js You may need to install the latest…
As nodes are added and deleted in a Hadoop cluster. Storage usage across DataNodes may be different. Some DataNodes’ disks are almost used up while some others’ are almost empty. How to balance data across DataNodes in HDFS? Hadoop provides the balancer to redistribute the data. Brief introduction to balancer in Hadoop: balancer. The design…