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Installing Zlib in Ubuntu 22.04

Zlib is a popular open-source compression library used by many software applications to compress and decompress data. It provides fast and efficient compression and decompression algorithms that can be used to reduce the size of data, which can improve performance and reduce storage requirements. In this post, we will discuss how to install zlib in…

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How to Install Hyperledger Fabric 2.0 in Ubuntu 18.04

Hyperledger Fabric is a consortium blockchain system. It’s performance is relatively good and its modular architecture enables it to be usable in many scenarios. Hyperledger Fabric itself has rich documents and samples of test networks. For beginners, deploying a new network for trying and testing still consumes quite some time. In this post, we will…

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How to synchronize OneDrive and OneDrive for Business files in Linux using Insync

OneDrive is one of the good cloud storage services available and there is a business version called OneDrive for Business. Microsoft’s Office 365 plan is widely used including Exchange Email service and OneDrive for Business. However, there is no official client released yet for Linux users. Insync is a third party cloud storage syncing software…

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How to Statically Link OCaml Programs

Static linking is preferred for some cases although it has its own various problems. Static building/linking is not always possible for some languages on some platform. For OCaml, the answer to this question is yes. In this post, we will introduce 2 methods to statically linking OCaml: static linking with runtime glibc required and static…

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How to synchronize Google Drive and Google Docs files in Ubuntu/Debian/Mint Linux using Insync

Google Drive is a nice cloud storage service. It provides a suite of nice online document spreadsheet and slide editors Google Docs, Google Sheets and Google Slides. The collaborative editing and full history tracking features of Google Docs are excellent. Google Drive gives 16GB free storage which is pretty much larger compared to other free…

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Installing Zlib from Source Code in Ubuntu Linux

Zlib is a popular open-source compression library used by many software applications to compress and decompress data. While it can be installed in Ubuntu using the apt package manager, you may need to install it from the source code if the version available in the Ubuntu repositories is outdated or if you need to customize…

Latex is stuck with a strange problem, see more information for details.

$ make pdflatex main.tex This is pdfTeX, Version 3.14159265-2.6-1.40.16 (TeX Live 2015/Debian) (preloaded format=pdflatex) restricted write18 enabled. entering extended mode (./main.tex LaTeX2e <2016/02/01> Babel <3.9q> and hyphenation patterns for 81 language(s) loaded. (/usr/share/texlive/texmf-dist/tex/latex/base/article.cls Document Class: article 2014/09/29 v1.4h Standard LaTeX document class (/usr/share/texlive/texmf-dist/tex/latex/base/size10.clo)) (./usenix.sty (/usr/share/texlive/texmf-dist/tex/latex/psnfss/mathptmx.sty)) (/usr/share/texlive/texmf-dist/tex/latex/graphics/epsfig.sty (/usr/share/texlive/texmf-dist/tex/latex/graphics/graphicx.sty (/usr/share/texlive/texmf-dist/tex/latex/graphics/keyval.sty) (/usr/share/texlive/texmf-dist/tex/latex/graphics/graphics.sty (/usr/share/texlive/texmf-dist/tex/latex/graphics/trig.sty) (/usr/share/texlive/texmf-dist/tex/latex/latexconfig/graphics.cfg) (/usr/share/texlive/texmf-dist/tex/latex/pdftex-def/pdftex.def (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/infwarerr.sty) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ltxcmds.sty))))) (/usr/share/texlive/texmf-dist/tex/generic/oberdiek/ifpdf.sty)…

Printing “powernow-k8 transition frequency failed” after install XEN

After I installed XEN hypervisor, the tty0 (CTRL+ALT+F1) prints “powernow-k8 transition frequency failed” to STDOUT continously, how to solve it? sudo rmmod powernow_k8 From https://lists.debian.org/debian-user/2013/01/msg00754.html How to make the settings persistent (take effect after reboot)? 1, Create script file ‘/etc/init.d/stop_pwoerk8.sh’ as follows. harry2vera@node1:/etc/init.d$ cat stop_pwoerk8.sh #! /bin/sh rmmod powernow_k8 2, Add the full PATH of…

rtnetlink answers file exists

When you replace dynamic IP to static IP, you may need to restart your netwrok on Debian as follows. $sudo /etc/init.d/networking restart … …. reconfiguring network interfaces…rtnetlink answers file exists … However, error happens here “rtnetlink answers file exists”. How to solve it??? Run following commands could solve this problem # ip addr flush dev…

How to email admins automatically after a Linux server starts?

Managing a cluster of servers, I would like to notified when a server is started. How to make the Linux servers email me or other admins automatically after they are started? I did this by adding a crontab entry on each servers like @reboot date | mailx -S smtp=smtp://smtp.example.com -s “`hostname` started” -r zma@example.com zma@example.com…

Finding All Available Versions of a Package in Ubuntu

How to find all available versions of a package in Ubuntu? To list available versions of a package: apt-cache showpkg <package-name> For example, to check all versions of thunderbird: $ sudo apt-cache showpkg thunderbird Package: thunderbird Versions: 1:31.1.1+build1-0ubuntu0.14.04.1 (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty-updates_main_binary-amd64_Packages) (/var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_trusty-security_main_binary-amd64_Packages) Description Language: File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty_main_binary-amd64_Packages MD5: 68ed1001b79d708ad48956a0c129114d Description Language: en File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_trusty_main_i18n_Translation-en MD5: 68ed1001b79d708ad48956a0c129114d 1:31.0+build1-0ubuntu0.14.04.1 (/var/lib/dpkg/status)…

Cannot connect QEMU guest os with vncviewer

The question is as follows. harry@debian:~/workshop1/qemu_test/version1/test$ qemu-system-x86_64 -hda qcow2.img -cdrom domU-x86_64-FS.img -boot d -m 1024 VNC server running on `::1:5900′ harry@debian:~/workshop1/qemu_test/version1/test$ vncviewer 127.0.0.1:1 vncviewer: ConnectToTcpAddr: connect: Connection refused Unable to connect to VNC server Solution (add -vnc parameter for qemu-system-x86_64): harry@debian:~/workshop1/qemu_test/version1/test$ qemu-system-x86_64 -hda qcow2.img -cdrom domU-x86_64-FS.img -boot d -m 1024 -vnc 127.0.0.1:2 harry@debian:~/workshop1/qemu_test/version1/test$ vncviewer 127.0.0.1:2…

Finding Which Package Provides a File in Ubuntu Linux and Linux Mint

How to find which package provides a file in Debian based releases, such as Linux Mint, Ubuntu? You can use `dpkg`: $ dpkg -S /path/to/the/file -S or –search is the option to make dpkg do a “search”: -S, –search filename-search-pattern… Search for a filename from installed packages. To search which package provides a command file…

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Notes for Beginners of Software Development on Linux

Linux is a great platform for software development targeting servers or backends. In general, working on Linux is very productive. The problem that beginners on Linux face is the the learning curve is steep at the beginning. But believe me, after you get through the initial green steep learning step as in the figure below…

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How to Run a Command Upon Files or Directories Changes on Linux

Doing actions upon changes of files and directories is very useful. Examples like compiling a project after the source code files are changed, sending emails after important configuration files are modified, building the PDF after a TeX file is modified. On Linux, the inotify-tools provide good support for trigger actions after changes. In this post,…