Email sender fraud is an annoying problem. Malicious email senders send spam emails with email senders that are under non-authorized domain names. This may affect the reputation of the domains used by the fraud sender. On another hand, lots emails will be rejected and reverted back, which causes lots additional work to the domain administrators.
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Category: Tutorial
Running Ephemeral Docker Containers – Automatically Remove a Docker Container After Running It
Posted onDocker is a convenient tool to quick create containers from different Linux images. If we use the common way to start a docker container like docker run image bash, after the the process exists, the container is still stored there. That is, the docker container persists after it has exited. Sometimes, we would like to
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Configuring Fonts for Thunderbird snap to Display Fonts Nicely
Posted onsnap is a software app bundle with dependencies included so that it can works in different Linux distributions. However, as most other software, snap has compatiblity issues. An app in the snap format is not 100% the same and compatible with the native version. One of the problem I find is that Thunderbird from snap
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Starting Page Number from the Second Page in MS Word
Posted onFor document, we may use the first page as the title page. Then the page number 1 should start from the second page. In this post, we will look at how to make MS Word count the page number from the second page. That is, making word treat the second page as page number 1.
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GNONE 3 Screenshot Keyboard Shortcuts
Posted onGNONE 3 provides screenshot tools and utils and also provides keyboard shortcuts which are convenient and quick to use. With the GNOME 3 screenshot keyboard shortcuts, users can make screenshots without having to open the Screenshot app. In general, there are 2 major categories of screenshot shortcuts: those to save the screenshot as a file,
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Reading JSON from URL in R
Posted onR is good at analyzing data. Many data are provided as JSON from RESTful APIs with an URL. R natively support many data format. For JSON, we can use some libraries. For reading JSON from URL, we can use the “jsonlite” package. In this example, we use an example of fetching BTC prices of last
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Reading Excel xls/xlsx Files in R
Posted onMany useful data are stored in Excel xls or xlsx format files. R is good at doing analysis on top of data. We would then need to import the data to R by reading the xls/xlsx files to be R data frames. In this post, we check how to import data from Excel files to
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3 Ways of .odt to .txt File Conversion in Command Line in Linux
Posted onThe Open Document .odt files can contain rich formats for the content. However, some times a plain text file is more handy. We may convert .odt files to plain text files for such needs. In this post, we discuss 3 ways of how to convert .odt files to .text files in command line in Linux.
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.docx/.doc to .odt File Conversion in Command Line in Linux
Posted onWord .docx and .doc files are common for documents commonly generated by MS Word software. We would like to convert them to the more open ODF Open Document .odt files for various cases. This can be done by GUI software tools. If we have a set of many .docx/.doc files, it will be handy if
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Configuring Eclipse to Show Git Revision Information in Editor
Posted onEclipse can work well with Git. We discussed Configuring Eclipse to Highlight Changed Lines Compared to Git Commit before. Eclipse can also show the revision information for lines of code (from git blame) which is useful to understand why some lines are added in the context of previous revisions including the lines of code. Eclipse
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2 Ways of Modifying macOS Keyboard’s Right Option to Control for Mac Pro
Posted onFor heavy Terminal/Shell/command line users, the Control key is a very frequently used key. However, in Mac Pro keyboard, there is only a single left Control key for some models. This cause quite some inconvenience. In this post, we will go through how to configure/remap the keys to “create” a right Control key. Remap keys
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Converting Hex to ASCII Using xxd
Posted onStrings are commonly encoded as hexadecimal (hex) strings for various purposes. Hence, it is also common to convert hex strings to its original strings such as an ASCII string. Hex to ASCII string conversion can be done programmatically in many languages. In command line, we can use xxd to convert hex to ASCII string. This
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Release Notes For Linux v2.0
Posted onThis is the release notes for linux release v2.0 (source code: linux-2.0.tar.gz) with format adjusted by removing/replacing tabs/spaces/new lines/formatting marks. This notes document can give us an understanding of the early development of the Linux kernel. The original ASCII formatted version is at the end of this post. Intro This document contains a list of
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Release Notes For Linux v0.95
Posted onThis is the release notes for linux release v0.95 (source code: linux-0.95.tar.gz) with format adjusted by removing/replacing tabs/spaces/new lines. This notes document can give us an understanding of the early development of the Linux kernel. The original ASCII formatted version is at the end of this post. RELEASE NOTES FOR LINUX v0.95 Linus Torvalds, March
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Configuring Eclipse to Highlight Changed Lines Compared to Git Commit
Posted onEclipse is one of the good IDEs for C/C++ projects with its great source code indexer. It is common the source code version is controlled by some tools like Git for software projects. It is convenient if the IDE can show the current changes compared to the committed code version. In this post, we will
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Generating RSA Private and Public Key Pair in Go Lang?
Posted onHow to generate a pair of RSA private and public key in Go lang? Go lang has a rich set of standard libraries. Using Go’s standard libraries, we can generate RSA private and Public keys. The Crypto standard libraries in Go lang Go lang standard libraries has a rich set of cryptography functions. Here are
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Printing Google Doc with Comments in Page Margins
Posted onGoogle Doc documents support comments which is useful for collaborative editing of files with comments to each others. But when we print the document from Google Doc, the comments are not included. How to print the document with comments in page margins? In this post, we will introduce a method using the opensource and free
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Printing Comments in Page Margins in LibreOffice
Posted on“Comments” and “tracking changes” are nice features of the opensource LibreOffice software (and other Office software) to add comments and track changes in documents. OpenDocument ODT and MS Word DOCX/DOC file formats all support comments and change trackings. When we print the documents, how to print the comments in the page margins too in LibreOffice?
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Clearing Git History in Local and Remote Branches
Posted onGit tracks changes as commits. This makes it possible and convenient to check the code change history in a repository. However, this also has side effect. The history consumes storage and the whole repository including the current version of the code files and all the previous changes may be quite large. This is especially a
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2 Ways of Resetting All Git Submodules in a Git Repository
Posted onGit submodule is a nice and convenient mechanism in Git to include the other Git repositories and manage the version/commit used from the submodule Git repository. However, there are cases where we would like “reset” the submodule, such as when we find updating a submodule repository will break the code tree, or merge some updates
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