I am trying to check my installation of hadoop. I did create the environment variables and when I call printenv, I do see my HADOOP_HOME and PATH variables printed and correct (home/hadoop and HADOOP_HOME/bin respectively). If I go to home/hadoop in the terminal and call ls, I see the hadoop file there. If I …
How to distinguish between pressed, released and long press when using QAbstractButton::autoRepeat
I am using Qt 4.8.X on Linux with X11 and/or Qt-QWS with custom buttons derived from QAbstractButton. Now I have to distinguish between a button press, release and the user holding down the button. To do so, I would like to use QAbstractButton::autoRepeat as described in this question. As the QT Documentation…
Keep previous information when running an executable from command lines
In Windows when I run an executalbe from command line, for example, abc.exe -i abc.bmp >output.txt, all the output of the program will be put in the text file. However, all the previous contents in the text file will also be destroyed. So if I run the following commands sequentially, Only the information w…
Setting channel volume in ALSA
My app plays raw PCM audio data through various channels using ALSA. I’m allocating a new audio channel by using snd_pcm_open(), then setting the PCM format via the snd_pcm_hw_params_xxx() calls and finally feeding raw PCM audio data to ALSA by using the snd_pcm_writei() API. This is all working fine so…
Usage of nfc tag ACR1251U on raspberry-pi
I have an NFC tag ACR1251U-A1. I need to use that with Raspberry Pi. I have installed the driver on Raspberry Pi via this link: http://www.acs.com.hk/download-driver-unified/6258/ACS-Unified-Driver-Lnx-Mac-110-P.zip But when I list the nfc devices on terminal by writing “nfc-list”, I don’t s…
Modify the return address of a C function with buffer overflow vulnerability
I am trying to modify the following C program so that the main function will skip the printf(“x is 1”) line and only print “x is 0”. As the comments imply, the ret pointer needs to first be set to the return address of the function. I then need to add on an offset that will push it ove…
NodeJs how to display table structured dashboard in console
How can I create a dashboard looking display in the console through nodejs? For example BFGMiner has a great looking structured UI: Answer I would use https://github.com/yaronn/blessed-contrib it comes with a lot of widgets built-in.
Log file permissions in Oracle WebLogic
I have changed the startWeblogic.sh script to give read access to the log files. Here are examples: From the above other users got read permissions for access.log and localhost.log, but its not assigning read access to localhost.out log file. Please suggest which configuration file to change. Answer set umask…
how to send different commands to multiple hosts to run programs in Linux
I am an R user. I always run programs on multiple computers of campus. For example, I need to run 10 different programs. I need to open PuTTY 10 times to log into the 10 different computers. And submit each of programs to each of 10 computers (their OS is Linux). Is there a way to log in 10 different
How to mount an external drive’s ext4 partition on android and make it rw-available to all the apps
I have written the following shell script: After executing the commands above, mount reports: I am working via ssh, remotely, using rooted ssh/sftp daemon, and while logged in as root, I can list the files in /storage/emulated/sda1. From what I understand, android is case-insensitive in regards to filesystems…