How to convert a MS Word document file such as .docx and .doc to pdf on Linux using command line tools? Use LibreOffice: libreoffice –headless –convert-to pdf –outdir /path/to/out/dir/ /path/to/doc/docx/file While this LibreOffice answer works, the –headless option still needs as display, even though it does not use it. In otherwords, this option won’t work…
This problem appears when I try to rsync directories with hosts inside a cluster used NAT for forwarding ports to internal nodes. Hence, the ssh port for internal nodes are not the default 22. So, how to use rsync with the non-standard ssh ports? The -e options of rsync play the trick very well. For…
It was ever possible to set it in gnome-teak-tool. However, in the latest Gnome 3, it disappears. Is there any other way to set it? The configuration is the org.gnome.desktop.wm.preferences titlebar-font under dconf. You can use dconf-editor to find the appropriate key entry and set it. Or use gsettings: $ gsettings set org.gnome.desktop.wm.preferences titlebar-font ‘Sans…
How to install Python environment in my own account on Dreamhost so that my application can use the python that I installed by myself instead of the system-wide one? The post for Bluehost works very well for Dreamhost too: https://my.bluehost.com/cgi/help/python-install In short: mkdir ~/python cd ~/python wget http://www.python.org/ftp/python/2.7.2/Python-2.7.2.tgz tar zxfv Python-2.7.2.tgz find ~/python -type d…
I messed up with one file in one repository and want to check out only that file back to a commit. How to achieve this? To check the file with my_file.name at git commit commit_sha1: $ git checkout commit_sha1 my_file.name You can also use the relative commit instead of commit_sha1 such as master~4, HEAD~4, HEAD^,…
I have access to different git servers. I have several keys for these servers. How to use different keys for different git servers? Use the .ssh/config file to specify different configuration for different SSH servers used by git: For example: Host git.example.org Port 22111 IdentityFile ~/.ssh/id_rsa.git.example.org Host code.example.org Port 22 IdentityFile ~/.ssh/id_rsa.code.example.org which specifies the…
libvirt uses files for VM images by default under /var/lib/libvirt/images/. LVM is a convenient tool for managing VM images. How to use LVM groups with libvirt? This post discusses the method to add LVM groups as a storage pool for libvirt: http://ailoo.net/2011/02/use-a-lvm-volume-group-with-libvirt/ For a general introduction of the storage management in libvirt, please check: http://libvirt.org/storage.html
There are lots internal and external links on my site. Unfortunately, some of them are broken over years. How to find out all these broken links on my site? I use this tool http://www.brokenlinkcheck.com/ which can detect the broken links well. More info here: Broken links checker for sites
My OCaml program prints: Fetal error: Exception “Stack_overflow” without any further information. How to find out which function causes this “Stack_overflow” exception? First, recompile your OCaml program with -g. Second, rerun your OCaml program with OCAMLRUNPARAM=b and the backtrace will be printed out after the “Stack_overflow” exception.
How to install sbt for scala on Fedora Linux? It is not included in the default Fedora repository although scala is included. The download page of scala-sbt.org provides the RPM package. You can install the sbt rpm package by yum. We only need the URL to the RPM package. Here, let take version 0.13.1 as…
Linux supports different timer sources and a machine can have multiple ones. How to find the available Linux timer source and the current one used? Find the current timer source: $ cat /sys/devices/system/clocksource/clocksource0/current_clocksource Find all available timer sources: $ cat /sys/devices/system/clocksource/clocksource0/available_clocksource
utop is an improved toplevel for OCaml supporting line edition, history, real-time and context sensitive completion, colors and etc. utop is convenient to use. However, the key bindings are a little bit different from the ones with GNU readline. What are all the key bindings? The #utop_bindings command will print all the key bindings. Here…
How to remove trailing spaces at the end of each line in a file on Linux? Use this script with sed: cat your_file | sed ‘s/[[:blank:]]+$//g’
I have some old emails left in the Evolution local directory (unfortunately not in the mail server’s imap directory). So how to import the Evolution directory which contains some files for the emails to Thunderbird so that I can copy them to the imap directory if needed? You can do this in two steps: First,…
This is the scenario: I want to remove a old hard disk which is a LVM PV and contains data. There is free space available on other PVs in the VG. It should move the data from the disk to be removed to other PVs and then remove the disk. The process to remove sdb…
An example of Xen HVM DomU configuration file. An example for install the OS from an ISO: name=”10.0.1.235″ vcpus=2 memory=2048 shadow_memory=8 disk=[‘file:/lhome/xen/vm-10.0.1.235/vmdisk0,xvda,w’, ‘file:/lhome/Linux-x86_64-DVD.iso,xvdc:cdrom,r’] vif=[‘bridge=xenbr0′] kernel=’/usr/lib/xen/boot/hvmloader’ builder=’hvm’ device_model=’/usr/lib64/xen/bin/qemu-dm’ extra=” vnc=1 vnclisten=”0.0.0.0″ vncpasswd=’1234567′ # vncdisplay=1 vncconsole=1 on_reboot=’restart’ on_crash=’restart’ An example for run the VM after installation: name=”10.0.1.235″ vcpus=2 memory=2048 shadow_memory=8 disk=[‘file:/lhome/xen/vm-10.0.1.235/vmdisk0,xvda,w’] vif=[‘bridge=xenbr0′] kernel=’/usr/lib/xen/boot/hvmloader’ builder=’hvm’ device_model=’/usr/lib64/xen/bin/qemu-dm’ extra=” vnc=1…
VM disks in public cloud may be shared by customers. This is privacy problem. Is there a quick method to sniff the data left on a Linux VM? One possible method: # dd if=/dev/xvda bs=1M | strings -n 100 > strings.txt Using the dd and strings which are pervasive on Linux systems.
How to set up auto indenting for OCaml code in Vim? The built-in indenting in Vim for OCaml seems not very good. Please check the post at https://www.systutorials.com/5212/auto-indenting-for-ocaml-code-in-vim-with-ocp-indent/
How to display the network usage by processes like top for CPU/mem on Linux? The nethogs tool is my favorite: nethogs – Net top tool grouping bandwidth per process
How to attach and mount Xen DomU’s disk to Dom0 To attach phy:vg_xen/vm-10.1.1.228 to xvda on Domain-0: # xm block-attach Domain-0 phy:vg_xen/vm-10.1.1.228 xvda w Mount the new partition /dev/xvda2 to /mnt/xvda2: # mount /dev/xvda2 /mnt/xvda2 After finishing using the partition, umount it and detach it: # umount /mnt/xvda2/ # xm block-detach Domain-0 xvda