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An example of recursion with Promises

A pattern for recursion with Promises - in this example, walking a directory structure.

Function flow

• readDirRecursive() is called with a starting directory and will itself return a Promise.
• Internally readDir() is called and passed starting directory to read from.
• A list of directory items is returned by getItemList() as a Promise, which in turn is chained to getItemListStat() to stat each item to determine if file or directory.
• Finalised list then passed to processItemList():

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Bash internal field separator (IFS) usage

The IFS internal variable is used to determine what characters Bash defines as word/item boundaries when processing character strings. By default set to whitespace characters of space, tab, and newline.

Running the example ifs.sh, comparing the difference between the default and setting only newline as a boundary we get the following output:

/path/to/first
file
/path/to/second

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Install Git on macOS from source

A quick n' dirty Bash script to install the following:

• autoconf, needed by Git configure.
• git - from source.

Tested successfully under both Intel and M1 (ARM64) based architectures.

Requires as a minimum Xcode CLI tools (no need for a full install). Can be installed via the following:

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NetScaler rewrite action to update a cookie key value

Making a note of this because NetScalers at just awful at anything when it comes to messing with HTTP header cookie values.

So I wish to update the value of a Cookie key of mykey= to mykey=new_value. I can do so with the following rewrite action:

• Type: REPLACE

• Expression to choose target location: HTTP.REQ.HEADER("Cookie")

• Expression:

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List all Git repository objects by size

• Summary
• Example

Summary

Bash script which will:

• Iterate all commits made within a Git repository.

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Stop Python urllib2 following HTTP redirects

By default calling a URL via urllib2 will follow any 30X responses returned, often not what you want.

We can correct this behavior by adding a custom "opener" class to the urllib2 module like so:

import urllib
import urllib2

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Install tig CLI Git repository browser tool

Without the need for Xcode bloat (yay!).

What is tig?: https://github.com/jonas/tig

# install gcc/make/etc.
# note: this will *not* install Xcode - don't be fooled by xcode in CLI command name
$ xcode-select --install

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Install VirtualBox guest additions onto Ubuntu server guests

Note

The following steps have been successfully tested with Ubuntu guests of:

• 24.04LTS
• 22.04LTS
• 18.04LTS
• 16.04LTS

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Enable LDAP over SSL (LDAPS) for Microsoft Active Directory servers

Tip

Microsoft active directory servers by default provide LDAP connections over unencrypted connections (boo!).

The steps below will create a new self signed certificate appropriate for use with and thus enabling LDAPS for an AD server. Of course the "self-signed" portion of this guide can be swapped out with a real vendor purchased certificate if required.

Steps have been tested successfully with Windows Server 2012R2, but should work with Windows Server 2008 without modification. Requires a working OpenSSL install (ideally Linux/OSX) and (obviously) a Windows Active Directory server.

• Create root certificate

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PowerShell execute command with arguments safely

In my opinion this is the best way for executing external commands from PowerShell with arguments in a safe manner - via the use of an array to hold the arguments.

Consider this one a PowerShell gem to keep in the toolbox.

Note

The example below makes use of EchoArgs.exe - a small utility that simply echoes back arguments passed to it. Utility is part of the PowerShell Community Extensions, or the exe alone can be downloaded at https://ss64.com/ps/EchoArgs.exe.

Example