Open geth (and other) binaries on MacOS

Recently, I had a problem opening the geth binaries (one of the Ethereum execution clients) on macOS.

 

After a short internet search, I found it was caused by extended attributes check. The problem like that occurs when the unsigned software is downloaded from the internet, but only using a web browser. When the curl or wget commands are used, there are no extended attributes assigned to the file.

 To check if the file has extra attributes, you can run a simple `ls -l` command and look for the `@` character.

> ls -l
-rwxr-xr-x@ 1 wawrzek  staff  45986920 17 Apr 07:06 geth

The list of attributes can be obtained with the `xattr` command:

> xattr geth
com.apple.quarantine

The same command can be used to remove the attribute

> xattr -d com.apple.quarantine geth

what enables an application to run.

Logitech MX Keys S on macOS and Linux (Crux)

 Before I forget again.

- On macOS, the UK keyboard is recognised as the ISO (International) one. That maybe causes the problem with the location of the ['`','~'] key. It's mixed up with the ['§','±'] one. I wrote maybe, because today I manually set it up to the ANSI option. That fixed the problem. But then, for a test, switched back to ISO, and it still works fine. Maybe my problem is because I connected the keyboard to a USB switch, rather than directly.

- Officially, Logitech supports Logi Option + software on Windows and Mac, but on Linux we have Solaar. It works, and if you are a Crux user, I created a port for it.

Open file from command line (in Linux and Macos)

One of the nice feature of MacOS is the open command. It allows opening files directly from the command line without knowing the application linked to the file type. For example:

 open interesting.pdf 

opens the interesting.pdf file using whatever program is assigned to open PDF files. (If you want more example about the open command, you can check this link.)

For some time I wonder about a Linux equivalent. Recently decided to look for it more actively and check if AI might help. It did, and pointed at the gio command from the Gnome Input/Output library. After adding a function or an alias following block of code to the .zshrc, I have a Linux equivalent.

•  alias

open="gio open"

• function:

open () {

    gio open $1

}   

And finally, xdg-open is an alternative for the "gio open".

Ansi control characters in Vim

The ANSI/VT100 terminals and their emulators allows to use escape sequences to  display colours and formatted text. (Check this link for more information on how to do this.) That's look cool in a terminal window. Problems starts when terminal output is redirected to a file (e.g. logs). Editors like Vim are virtual useless with such files, because files are full of "rubbish". At least by default, because for Vim there is a good plug-in called "Asci Highlighting". It takes escapes sequences and colour text appropriately.


Links:

• https://misc.flogisoft.com/bash/tip_colors_and_formatting 
• http://www.drchip.org/astronaut/vim/index.html#ANSIESC

OpenSSL and Azure VPN

I had to set up an Azure Point-to-Site VPN, but didn't want to do it from Windows machine (I'm Linux/MacOSX kind of the guy) but luckily I found this Aris Plakias' article which describe in a plain language with good example how to prepare all necessary certificates using OpenSSL.

Actually I've created this small script so I can easily repeat client creation step.

#/bin/sh
name=$1
openssl genrsa -out ${name}1Cert.key 2048
openssl req -new -out ${name}1Cert.req -key ${name}1Cert.key -subj /CN="MyAzureVPN"
openssl x509 -req -sha256 -in ${name}1Cert.req -out ${name}1Cert.cer -CAkey MyAzureVPN.key -CA MyAzureVPN.cer -days 180 -CAcreateserial -CAserial serial
openssl pkcs12 -export -out ${name}1Cert.pfx -inkey ${name}1Cert.key -in ${name}1Cert.cer -certfile MyAzureVPN.cer

Control terminal name and comment block in VIM

Somewhere (I think it was Stackoverflow) I found simple command to control the name of terminal from commandline which works very nice with iterm2 tabs on MacOSX and decided to add to my zsh environment this function:

termname() {
 echo -en "\e]1; $1 \a"
}

And if we are saying about Stackoverflow one of the most useful Vim suggestion I've ever found is this instruction to comment/uncomment a multiple lines in VIM.

DarwinPorts via proxy

Recently, I needed a perl module not present on my MacOSX computer, which was behind a proxy. The friend suggested to use the Darwin ports rather the Perl from Apple. I downloaded and installed it to found I cannot install any port. The problem was due to the combination of using a proxy and the sudo rather then the root user. I guess such combination is rather common among MacOSX-perl users. So below I present the command which allows to use the Darwin ports from a normal MacOSX account. Generally note, you have to export both the RSYNC_PROXY as well as the http_proxy in the sudo environment.

sudo sh -c "export RSYNC_PROXY=proxy.server:port; \
export http_proxy=http://proxy.server:port; \
port install perl5.10 "

Gnuplot with readline on MacOSX

Recently, I tried to use gnuplot on a Mac, and, of course, it wasn't working properly. Apple prepared and shipped with MacOS its own (broken) version of readline library with didn't work with gnuplot (known bug). So I grabbed the sources of readline, applied all of patches and built mine version of readline. Next, I added the proper option to gnuplot configure file, but it wasn't pass to makefile. I looked into the Makefiles and found the the TERMLIBS option had to be change. I.e. using such command:

find . -name Makefile \
-exec sed -i.old "s/TERMLIBS\ =/TERMLIBS = -L\/usr\/local\/lib/" {} \; 

Two more things about gnuplot and MacOSX.

1. I started to think to make a gnuplot.app for MacOSX, but sure how it should work.
2. I found that X11 term is much better then Aqua, in particular, it's allow to rotate 3D (s)plots.

Very useful MacOSX key shortcut

The apple+tab key combination change between apps on MacOSX, but it works for one windows per application. What if you have more than one window for app? It is quite common when you are using X11 applications or try to use more than one terminal. To change between active window of one app you can use apple+', but it seems works only for windows on one desktop. It also not work for X11 app, but for them you can use apple+left/right arrows. One more thing. In some instruction related to MacOSX apple key is called comm and alt - option.

Tips for starting MacOSX apps

1. If you want to start a MacOSX applications from a terminal (or a shell script) you have to use the open command, i.e.: open /Application/Firefox.app (based on xahlee.org)
2. If you need to write a wrapper starting a binary file (which is inside of a MacOSX app) with some options you can use following construction: HERE=`dirname $0`; $HERE/name.x -options The same construction is useful if you need to set some environment variables.
3. Sometimes is it necessary to have a location of an app, but apps can be place in a very strange places. MacOSX binaries are located third level deep inside of an app, so the following command save location of an app in the TOPDIR variable: TOPDIR=`cd $HERE/../../../; pwd`