The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘*nix-tools’ Category

Recovering files with scalpel.

Posted by jpluimers on 2021/04/19

I missed this 2014 article [WayBack] Recovering Deleted Files with Scalpel » Linux Magazine:

The Scalpel file carver helps users restore what they thought were lost files.

Via the now defunct G+ link: https://plus.google.com/+Doortodoorgeek/posts/eskyp8PH57a?_utm_source=1-2-2 from which I saved this quote:

+honkey Magoo recovering with Photorec can be hard, I had a touch more luck with this one

Scalpel File Carver: http://www.linux-magazine.com/Online/Features/Recovering-Deleted-Files-with-Scalpel

I wish it had been maintained longer, as the most recent changes are indeed from 2014: [WayBack] GitHub – sleuthkit/scalpel: Scalpel is an open source data carving tool. (it is now indeed part of Sleuthkit, see [WayBack] Scalpel – ForensicsWiki)

So basically this was a short revival: WayBack: Digital Forensics Solutions: Announcing Scalpel 2.0.

–jeroen

Read the rest of this entry »

Posted in *nix, *nix-tools, Apple, Mac OS X / OS X / MacOS, Power User | Leave a Comment »

Dockerfile with Bite Size Networking tools from b0rk

Posted by jpluimers on 2021/04/16

[WayBack] Ryan James Spencer on Twitter:

“I wrote a quick Dockerfile so people who purchase Bite Size Networking from  @b0rk can quickly have access to the tools. You can slim the image down to do debugging on docker networks once you get comfortable with which tools are most useful to you.”

He is planning to do more, so maybe a few of [WayBack] wizard zines get encapsulated into dockerfiles as well.

–jeroen

PS: [WayBack] Dockerfile | Docker Documentation


# N.B. The only tool missing here that is mentioned in the document is `zenmap`
# purely because this image is intended to be run via a CLI and `zenmap` is a GUI
# to `nmap` i.e. one can play around with the tools by running:
#
# $ docker build –name bite_size_networking:latest .
# $ docker run –rm -d –name bsn_test bite_size_networking:latest
# $ docker exec -it bsn_test bash
#
# Alternatively, one can change the `ENTRYPOINT` to `["bash"]` and run:
#
# $ docker run -it –name bsn_test bite_size_networking:latest
#
# then later (after exiting the shell):
#
# $ docker start bsn_test
# $ docker attach bsn_test
#
# One can also run this image on a docker network to capture packets and so
# forth for debugging purposes. Once you've found the tooling that best suits
# your needs, it may make sense to make a slimmed down version of this
# Dockerfile and, if wireguard isn't needed, base this image off
# `debian:stable` instead.
#
# Lastly, you can purchase Bite Size Networking or Julia's other fantastic
# zines over at https://wizardzines.com/
# We use `unstable` here since we install `wireguard` below
FROM debian:unstable
RUN apt update && \
DEBIAN_FRONTEND=noninteractive apt install -y \
dnsutils \
curl \
nmap \
tcpdump \
ngrep \
mitmproxy \
iptables \
ethtool \
stunnel \
hping3 \
lsof \
ipcalc \
p0f \
iperf \
apache2-utils \
wget \
python3 \
iftop \
nethogs \
iptraf \
httpie \
nload \
aria2 \
nftables \
tcpflow \
telnet \
openvpn \
links \
wireguard \
tshark
ENTRYPOINT ["sh", "-c", "while true; do sleep $(( 60 * 60 * 24 )); done"]

Posted in *nix, *nix-tools, Cloud, Containers, Docker, Infrastructure, Power User | Leave a Comment »

The Architecture of Open Source Applications: Sendmail

Posted by jpluimers on 2021/04/12

Cool historic article: [WayBack] The Architecture of Open Source Applications: Sendmail by Eric Allman.

It is Chapter 17 of this book [WayBack]:

The Architecture of
Open Source Applications

Amy Brown and Greg Wilson (eds.)
ISBN 978-1-257-63801-7

I totally missed that book being published in 2014.

Great historic read!

–jeroen

Posted in *nix, *nix-tools, History, Power User, sendmail | Leave a Comment »

linux – How can I execute a series of commands in a bash subshell as another user using sudo? – Stack Overflow

Posted by jpluimers on 2021/03/31

Based on [WayBack] linux – How can I execute a series of commands in a bash subshell as another user using sudo? – Stack Overflow:

alias restart-spotlight-service-as-root="sudo bash -c 'echo stop;launchctl stop com.apple.metadata.mds;echo start;launchctl start com.apple.metadata.mds;echo started'"

The bold bits above sudo bash -c 'echo stop;launchctl stop com.apple.metadata.mds;echo start;launchctl start com.apple.metadata.mds;echo started' allow the commands between single quotes to executed in one new bash shell under sudo.

–jeroen

Posted in *nix, *nix-tools, Apple, bash, bash, Development, Mac OS X / OS X / MacOS, Power User, Scripting, Software Development | Leave a Comment »

email file decoding: Encode/Decode Quoted Printable – Webatic

Posted by jpluimers on 2021/03/26

For my link archive: [WayBack] Encode/Decode Quoted Printable – Webatic.

It did a splendid job at decoding email files in MIME format Quoted-printable.

–jeroen

Posted in *nix, *nix-tools, Communications Development, Development, eMail, Encoding, Internet, Internet protocol suite, Power User, sendmail, SMTP, SocialMedia, Software Development | Leave a Comment »

flush deferred messages in mail queue – SysAdmin Tips

Posted by jpluimers on 2021/03/19

[WayBack] flush deferred messages in mail queue – SysAdmin Tips

In Exim:

# exim -qff

In Postfix:

# postfix flush

In Sendmail:

# sendmail -OTimeout.hoststatus=0m -q -v

–jeroen

Posted in *nix, *nix-tools, exim mail, postfix, Power User, sendmail | Leave a Comment »

Inspecting Postfix’s email queue – Tech-G

Posted by jpluimers on 2021/03/08

[WayBack] Inspecting Postfix’s email queue – Tech-G:

mailq

or

postqueue -p

then

postcat -vq XXXXXXXXXX

Process (flush) the queue:

postqueue -f

OR

postfix flush

Viewing which senders/receivers are in the queue most:

Try with:
– qshape

More specific:
qshape -s deferred | head ===> deferred mails based on SENDER
qshape deferred | head ===> deferred mails based on RECEIVER

Rate limiting: [WayBack] Postfix Configuration Parameters: default_destination_rate_delay

–jeroen

Posted in *nix, *nix-tools, postfix, Power User | Leave a Comment »

Postfix TLS Support

Posted by jpluimers on 2021/02/25

For my link archive:

–jeroen

Posted in *nix, *nix-tools, Communications Development, Development, Internet protocol suite, postfix, Power User, SMTP | Leave a Comment »

showthedocs

Posted by jpluimers on 2021/02/18

[WayBack] showthedocs

is a documentation browser that finds the relevant docs for your code. It works by parsing the code and connecting parts of it to their explanation in the docs

, and supports these languages:

  • SQL
    • postgresql
    • mysql
  • Configuration
    • nginx
    • gitconfig

You can enter any language text, then click the language, followed by clicking the “SHOW ME THE DOCS!” button, for which an example is further below.

The site has an open architecture, allowing to plug in more languages and documentation:

 

gitconfig example

So for instance the below ./git/config file leads to this result [WayBack] where you can click on all the coloured areas for easy navigation through the documentation:

Read the rest of this entry »

Posted in *nix, *nix-tools, Database Development, Development, DVCS - Distributed Version Control, git, MySQL, nginx, PostgreSQL, Power User, Software Development | Leave a Comment »

explainshell.com: parse and explain just about any shell command

Posted by jpluimers on 2021/02/17

I bumped into the tremendously site [WayBack] explainshell.com – match command-line arguments to their help text only after documenting the relevant cURL options of yesterdays post on checking your CertBot domain expiration dates.

The site allows put in a shell command-line to see the help text that, including matches for each argument.

It works so well because it parses both the shell command-line and the man pages, then constructs a web-page linking the relevant man page content to the shell command-line in the correct shell command-line order.

The explainshell has a counterpart showthedocs (both are open source) for explaining other languages (on the one hand more extended as it goes much deeper into parsing for instance SQL, on the other hand more limited as it only supports a few languages). More on showthedocs later.

The links

The parsing results

The first bit below is just the text output, and the second bit the screenshot, of a relatively simple command like [WayBack] explainshell.com – curl -fsSL example.org:

curl(1) -fsSL example.org
transfer a URL
-f, --fail
       (HTTP)  Fail  silently  (no  output at all) on server errors. This is mostly done to better enable
       scripts etc to better deal with failed attempts. In normal cases  when  a  HTTP  server  fails  to
       deliver  a  document,  it  returns an HTML document stating so (which often also describes why and
       more). This flag will prevent curl from outputting that and return error 22.

       This method is not fail-safe and there are occasions where non-successful response codes will slip
       through, especially when authentication is involved (response codes 401 and 407).
-s, --silent
       Silent or quiet mode. Don't show progress meter or error messages.  Makes Curl mute.
-S, --show-error
       When used with -s it makes curl show an error message if it fails.
-L, --location
       (HTTP/HTTPS) If the server reports that the requested page  has  moved  to  a  different  location
       (indicated  with  a Location: header and a 3XX response code), this option will make curl redo the
       request on the new place. If used together with -i, --include or  -I,  --head,  headers  from  all
       requested pages will be shown. When authentication is used, curl only sends its credentials to the
       initial host. If a redirect takes curl to a different host, it won't  be  able  to  intercept  the
       user+password.  See  also  --location-trusted  on  how to change this. You can limit the amount of
       redirects to follow by using the --max-redirs option.

       When curl follows a redirect and the request is not a plain GET (for example POST or PUT), it will
       do  the  following  request  with a GET if the HTTP response was 301, 302, or 303. If the response
       code was any other 3xx code, curl will re-send the following request  using  the  same  unmodified
       method.
source manpages: curl

The screenshot is even more impressive:

Read the rest of this entry »

Posted in *nix, *nix-tools, bash, bash, Development, Power User, Scripting, Software Development | Leave a Comment »