Questions and answers.
The result of git by git diff –word-diff is great. But how to do diff like git diff –word-diff without git on Linux? The plain diff command on Linux seems not accept options like –word-diff. The wdiff is for word-diff: wdiff program is a front end to diff for comparing files on a word per…
How to convert PDF to text with format kept on Linux? Many of the formatting in PDF will not be available in text. But better keep the text’s relative positions as the same. For example, the table columns should be kept. The pdftotext tool can convert PDF to text pretty well: pdftotext – Portable Document…
$ git add file $ git commit -m “xxxx” $ git push error: The requested URL returned error: 403 Forbidden while accessing https://github.com fatal: HTTP request failed Change your ~/.gitconfig as follows: $ cat ~/.gitconfig [user] name = xxx email = xxx@gmail.com [remote “origin”] fetch = +refs/heads/*:refs/remotes/origin/* url= https://name@github.com/name/xxx.git
How to install driver for TP-LINK T2U wifi adapter on Linux? I am using Fedora Linux 22. The kernel module for the driver for TP-LINK T2U is “mt7650u_sta”. TP-LINK and mediatek provide drivers (mediatek one is for 7610u). But neither work for Fedora 22 AFAIK. This piece of modified driver work for me on Fedora…
Firefox needs an email address and a password to login and sync. Is Firefox Sync safe, that is, could someone else read my password saved in Firefox without my password? In short, only you with your password can see your data. Others, even Mozilla’s servers, without your password, can not see your decrypted data. In…
Where can I find the source code for the free command on Linux? The source code for the free commands (and many more, like kill, ps, top, sysctl) can be found in procps-ng: https://gitlab.com/procps-ng/procps procps is a set of command line and full-screen utilities that provide information out of the pseudo-filesystem most commonly located at…
From the opening window by JavaScript window.open(), we can pass info to the opened by hash. But how to pass results back from the opened window to the openning window in JavaScript? Assume in the opener window, a JavaScript variable is defined like var exchangeVar = ”; In the opened window, you can update the…
How to capture the close event of an opened window by window.open() in JavaScript? This JavaScript code works well for me: var newwindow = window.open(“/newwindow.html”); newwindow.onbeforeunload = function () { // processing event here alert(“new window closed”); } Note that after the callback function is executed, the newwindow is closed.
How to convert general JavaScript objects to json in Node.js? Assume jo is a JavaScript object, you can convert it to a json string by: JSON.stringify(jo)
How to install the Chrome browser on Fedora Linux from Google? Google provides a repository for yum/dnf on Fedora. First, following http://www.systutorials.com/3471/additional-repositories-for-fedora-linux/#google-chrome-repository to add Google Chrome repository. Then, you can install Google Chrome by yum/dnf: # dnf install google-chrome-stable
This post introduces a key presser on Linux with xvkb. But how to simulate pressing multiple keys together on Linux? That is, I would like to have multiple keys such as “A” “B” “C” “D” pressed together and being hold. How to simulate this on Linux with programs/commands? You can make use of xdotool (xdotool:…
How to cut by multiple spaces in Linux? For example, if I get a string like a b c d where the spaces among the fields are not decided. How to get the four fields a, b, c and d out? Here, we take getting ‘b’ (the 2nd field) as the example. You can first…
How to get a file’s size in Python from the full path of a file? You can use this piece of Python code: os.path.getsize(file_path) It returns the size in bytes. It raises os.error if the file does not exist or is inaccessible. Manual of os.path.getsize(): https://docs.python.org/2/library/os.path.html#os.path.getsize
How to send POST request in JavaScript from the users’ browsers? One easy method I find is to use the jQuery library’s post() method. Here is one example that send POST request with data “file: filename” to the “/fileview” URL on the server and show the replied data: $.post(“/fileview”, {file: filename}, function (data) { //…
How to open a URL in a new window in JavaScript? For example, to open a new window to browse “http://www.systutorials.com“. Open the URL in a new window: url = “http://www.systutorials.com”; window.open(url); Some browser will open the window in a new tab depending on the configuration. If you want to force the browser to open…
When uploading a file by the hdfs dfs -put command line in HDFS, how to set a replication factor instead of the global one for that file? For example, HDFS’s global replication factor is 3. For some temporary files, I would like to save just one copy for faster uploading and saving disk space. The…
How to iterate all files and directories under a directory in Python? For example, I would like to iterate each file and directory under /mnt/data/ /mnt/data/ |– file.txt `– great That is: /mnt/data/files.txt /mnt/data/great You can use the os.walk to do this: root, dirs, files = os.walk(path).next() root will be the path.dirs will contain the…
How to get the file extension from a filename in Python? For example, I would like to get “.txt” from “file.txt”. The Python code: >>> name, ext = os.path.splitext(‘file.txt’) >>> name ‘file’ >>> ext ‘.txt’ Manual of os.path.splitext: https://docs.python.org/2/library/os.path.html#os.path.splitext
Some JavaScript libraries send data by POST instead of JSON. In node.js, how to parse the POST data? You can use the “querystring” module: var qs = require(‘querystring’) The following piece of code works well for me. The comments should help you read the code well. var post_handle = function(request, response) { if (request.method ==…
How to detect the #hash and get the hash in JavaScript? It’s better if no additional library is needed. That said, jquery is fine if it is needed. You can use this piece of JavaScript code: if (window.location.hash) { // hash found var hash = window.location.hash.substring(1); } else { // No hash }