Linux

PDF annotation tools on Linux

What are good PDF annotation tools on Linux? Preferring saving the annotation in the PDF instead of separate files or images. I find the best solution may be wine + Foxit Reader. Foxit Reader can annotate PDF files and save them. It works very well on wine. Steps to install them: Install wine # yum…

Force Linux to reboot

How to force Linux to reboot when the reboot command does not work. Enable the use of the magic SysRq option: # echo 1 > /proc/sys/kernel/sysrq Reboot the machine: # echo b > /proc/sysrq-trigger Even if you could not log on the system but sshd is working, you can force the Linux to reboot by:…

How to install Scala from the official Scala distribution

How to install Scala from the official Scala distribution? This is needed on a Linux release with older version of Scala in the repository, e.g. Fedora 12. Use the install-scala.sh script: # wget https://raw2.github.com/zma/usefulscripts/master/script/install-scala.sh # sh ./install-scala.sh VER where VER is the scala version that you want to install. First step, install and configure the…

Plain text file pipelined to Linux mailx turns to “Content-Type: application/octet-stream” (an attachment)

Plain text file pipelined to Linux mailx turns to “Content-Type: application/octet-stream” which is recognized as an attachment by some email client. The command is like this: $ cat log.txt | mail -s “Updated log file” -r “from@example.com” “to@example.com” I expect it to be: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit But it turns out to be: Content-Type:…

Where are the Linux routing table entries stored on disk?

I know the routing tables on Linux is in memory after being set. However, where are the routing table entries stored on disk? I mean where are the routing table is persistently stored so that the routing table can be reloaded like the iptables (under /etc/sysconfig/iptables on Fedora/RHEL/CentOS Linuxes). If the system uses the /etc/rc.d/init.d/network…

Good tools to manage OCaml packages

Which tools to mange OCaml packages in my system (Linux)? I use OPAM to manage OCaml packages: http://opam.ocamlpro.com/index.html To install it: $ wget https://raw.githubusercontent.com/ocaml/opam/master/shell/opam_installer.sh $ sh ./opam_installer.sh /usr/local/bin More options are available here. To make opam settings take effect, append this to ~/.bashrc: eval `opam config env` Some frequent usages: opam list # List all…

Chrome’s KDE proxy integration broken on KDE / Fedora

Chrome reads the proxy settings from Gnome correctly. However, when I run Chrome under KDE, the proxy integration is broken: In the settings of Chrome, clicking the “Change proxy settings” opens the KDE proxy setting dialog correctly (the command kcmshell4 proxy actually is executed). However, after the proxy settings are made, Chrome does not read…

How to turn my iPhone to a mouse?

iPhone has the touch screen. Is is possible to turn my iPhone to a wireless mouse on Linux? Use the WiFi Mouse app/server: http://wifimouse.necta.us/ First, install the WiFi Mouse app on you iPhone: https://itunes.apple.com/app/id591076411?mt=8 Second, install the WiFi Mouse server downloaded from http://wifimouse.necta.us/ If you are using Fedora Linux, you need to convert the .deb…