The LaTex packages in CentOS 7 Linux is not sufficient enough. I would like to Install Tex Live such as Tex Live 2016. How could I install it on CentOS 7? The best way I found is to use the texlive offical installation tool to install the full packages for texlive 2016. It will take…
How to extract the images from a PDF file in Linux? You may use the pdfimages tool. To output jpg images from a PDF ./a.pdf, run pdfimages -j ./a.pdf ./images ./images is the output images’ prefix. The images in ./a.pdf will be extracted and saved as ./images-nnn.jpg. -j options make pdfimages generate JPEG files.
In Linux Kernel, we usually trace/debug what kind of events will trigger the phenomena we find in the system. For example, what kind of event will trigger the fact that the timeslice of one process will be very short. In order to solve these kind of problems, we need to output the function stack. Currently,…
On CentOS 7, using a normal user, encfs works just well. On CentOS 6, using the root user, encfs works. However, the problem is, on CentOS 6, using a normal user account, encfs does not work as on CentOS 7. $ encfs -s ~/t/.enc ~/t/enc EncFS Password: fuse: failed to exec fusermount: Permission denied fuse…
Dia seems not available in the official repository of CentOS 7. How to install dia on CentOS 7 Linux? You can find built dia packages in some additional repositories for CentOS. First, enable EPEL following this link. Second, enable Nux Desktop following this link. Then, you can install dia by # yum install dia
In Bash script, how to join multiple lines from a file? For example, to join the lines a good boy to a good boy You can use tr command, something like: tr -s ‘n’ ‘ ‘ < file.txt It just goes through its input and makes changes according to what you specify in two sets…
The gnome 3 classic’s bottom panel looks not useful to me. I do not use it. How to remove the bottom panel in gnome 3 classic? That bottom panel is from the “Window List” plugin. The gnome 3 classic package depends on that plugin package on CentOS 7 as far as I checked. And Gnome…
I have a website. But I would like use the www.example.com instead of example.com. How to redirect non-www domain to www domain on my server? I am using apache2 (httpd). You can add a piece of code into the top .htaccess in your site: Specific method: redirect example.com domain to www.example.com domain RewriteEngine On RewriteBase…
xsane’s output jpeg file is large (10+MB). But we usually do not need it to make a so big jpeg file. Some compression (even lossy) will be good. How to make output jpeg file of xsane smaller on Linux? You can adjust the output file size by changing the compression levels and quality. Through the…
In the screen, copying the history of the window output is quite hard. How to save the screen easily to a file? First type Ctrl + A then : to get to command mode. In the command mode, execute hardcopy -h /path/to/file screen will save the window output to /path/to/file.
Before reading or writing a file, access should be checked first. How to detect whether a file is readable and writable in Python? You can use the os.access(path, mode) library function https://docs.python.org/release/2.6.6/library/os.html#os.access like the Linux access library function for C. It returns True if access is allowed, False if not. For readable and writable, you…
How to set up the driver for an HP all-in-one printer/scanner on CentOS 7 Linux? First, install these packages and it may ask you to download and install other plugins. Without these packages, my printer does work. # yum install hplip hplip-gui hpijs Second, install plugins for the HP printer. # hp-plugin Then you can…
I would like to make tee catch the stderr and log it into a file. A brute force method by let tee listen on both stderr and stdout is okay like cmd 2>&1 | tee -a log But how to make tee catch the stderr only? You can make use of “process substitution” (>(…)) to…
The common rsync commands seems not handle spaces well. For example, rsync -avxP file “user@server:/data/my dir” It reports: rsync: link_stat “/home/zma/file” failed: No such file or directory (2) How to make rsync handle spaces well? You can use the –protect-args option of rsync. $ rsync –protect-args -avxP file “user@server:/data/my dir” What does –protect-args do: -s,…
It is common to make a unique temporary file. How to make a unique temporary file in Bash on Linux safely and quickly? You can use the mktemp program. In the simplest way, tmpfile=$(mktemp) The file will be like /tmp/tmp.j0wD39Mr3b if you do not prefer any meaningful names. You can set the file to your…
How to check whether a key already exists in a dict in Python since version 2.6? If d is a dict(), you can directly test whether a key k is in d in Python by the in keyword like if k in d: ..
Sometimes, we may want to know the specific benchmark can cause what kind of VM exits. 1, Install perf. 2, # perf kvm stat record -a ^C 3, # perf kvm stat report This will report your VM exit numbers and what kind of operation lead to VM exit. You may need to compare many…
curtlftpfs is a nice tool to mount ftp to local. How to install curlftpfs on CentOS 7? The software package for curlftpfs is proved in EPEL. To install curlftpfs, first, enable EPEL following instructions here. Then, install curlftpfs by # yum install curlftpfs
When we create VMs in KVM, we may don’t know the IP addresses because they are automatically assigned by DHCP. So we want to get them in VMM so that can login by SSH. Do the commands as follows. $ virsh domiflist hvm1 Interface Type Source Model MAC ——————————————————- vnet0 network default virtio 52:54:00:1c:36:cd $…
For my case, I need to bypass one intermediate server so that I can connect to the remote server with vnc. For example, there are two servers (s1, s2) except my local PC and I have to login to s1 so that I can login s2 from my local PC. However, now, I need to…