Nano Shortcuts

I’ve know about nano and some it’s shortcuts. Today I explored them a bit more deeply.
So a list of shortcuts I find useful:

  • ctrl+K Cut the current line and put it in the nano clipboard (it’s not the same as the general clipboard)
  • ctrl+U Paste the line
  • ctrl+W Open search, type and hit enter. For the next match press alt+W
  • ctrl+Q Search backwards. For the next backward match press alt+Q
  • alt+U Undo
  • alt-E Redo
  • alt+C show the line number
  • alt-G Go to line number

Sources:

  • https://www.nano-editor.org/dist/latest/cheatsheet.html
  • https://askubuntu.com/a/672091/208343

sumcheck a whole directory

For some reason files changed on a server. Site down, always fun.
Restored a backup all good. This site did not have git on the server. But I still wanted to monitor the files for changes.

The one I landed on was:

find ./ -type f -name "*.php" -not -path "./wp-content/cache/*" -exec md5sum {} + | sort -k 2 | md5sum

Let’s dissect

What does this command do step by step

In the current directory and sub directory, list all files (not directories)

find ./ -type f

Limit it to php files

find ./ -type f -name "*.php"

Exclude the files in the caching directory, a bit weird syntax but it’s the one.

find ./ -type f -name "*.php" -not -path "./wp-content/cache/*"

For each file found run the command md5sum making a sum per file.

find ./ -type f -name "*.php" -not -path "./wp-content/cache/*" -exec md5sum {} +

Next we sort the output based on filepath+name.
We sort because find might return file order inconsistently.

find ./ -type f -name "*.php" -not -path "./wp-content/cache/*" -exec md5sum {} + | sort -k 2

Finally we create the grand total sumcheck based on all other sumchecks.

find ./ -type f -name "*.php" -not -path "./wp-content/cache/*" -exec md5sum {} + | sort -k 2 | md5sum

Sources:

  • https://stackoverflow.com/a/1658554/933065
  • https://unix.stackexchange.com/a/35834

Running php from command line

This is one of those “I know this is possible, but don’t know how”.

php -r '$parts = [ "hello", "world" ]; echo implode( " ", $parts ) . PHP_EOL;' # hello world

Only useful for simple onelines. You’re very likely to be better of putting code in a php file and run that script like:

php ./helloworld.php

Run PHP with WordPress loaded.

Of course your good old friend wp-cli can help.
It can run code with wp fully loaded. So if you add things in the init action or even after the wp_loaded, those plugin/theme functions, posttypes and such are all available.

First off the plain php code execution, with wp eval

wp eval 'var_dump(did_action( "wp_loaded" ));'  # int(1)

Secondly we execute a file with WordPress fully loaded using wp eval-file

wp eval-file ./helloworld.php

Curl output format

A lot of usefull informatoin can be caught using curl. Formating the output can be done with the -w --write-out argument

curl -w 'Home loadtime: %{time_total}\nResponse code: %{http_code}\n' -o /dev/null -s 'https://www.janw.me/'
Bash output of curl request

Output example:

This example will show the load time and response code. These 2 values are duable. But If you want more it’s more readable to pass a file.

In file: nano curlformat.txt

    time_namelookup:  %{time_namelookup}\n
       time_connect:  %{time_connect}\n
    time_appconnect:  %{time_appconnect}\n
   time_pretransfer:  %{time_pretransfer}\n
      time_redirect:  %{time_redirect}\n
 time_starttransfer:  %{time_starttransfer}\n
                    ----------\n
         time_total:  %{time_total}\n

Then pass the file to curl:

curl -w "@curl-format.txt" -o /dev/null -s "https://janw.me/"
Bash output of curl format file

A list of all avialable variables are in the man pages

Sources:

sed command line tool

sed is not new for me. But it’s such a versatile tool. And I always have trouble finding the precice syntax I need. So here is a collection of examples. It probably will grow in the years.

Replace the home dir with ~.

COMPACT=$(echo ${HOME} | sed "s#${HOME}#~#g")

Replace %SALT% with the variable $SALT in the file wp-config.php

sed -i -E "s/%SALT%/${SALT}/g"  "wp-config.php"

wp cli output format with –porcelain

wp db export

#output
Succes: Exported to 'dbname-2019-09-16-2790c11.sql'

Often you need the filename. And if you only need the file name that’s annoying to parse.

--porcelain flag to the rescue!

wp db export --porcelain

#output
dbname-2019-09-16-2790c11.sql

This will work on a lot of commands that have one item output.
Stuff like wp post create ....
Here is a complete list of commands that have the –porcelain flag

Commands that output more items usually have a --format flag to handle output.

Copy files/folders over ssh

Sometimes you just want to copy files from a remote server, and you want it often and quick. Stuff like a DB dump.
You could startup your (s)ftp client and browse to it. Or you could just grab it with ssh.

Download one file

scp -user@hostname.com:/full/path/to/dump.xml /local/path/to/Downloads

Download a whole folder

scp -r user@hostname.com:/full/path/to/folder /local/path/to/Downloads

If you need something more complicated, look into rsync

Bash edit command

I like doing a lot in one command. Downside it that stuff can get messy. One big line. you can’t easily edit it.
A shortcut to make it easier is ctrl-x-e That will open the current command in an editor.

Few thinks to keep in mind.

  • Multiple lines will work, but it will execute it as separate commands.
  • using && at the end of lines will fix that.
  • Which of course means you get it in the bash history at full.
    This is my main use to chain commands.

Bash argument set

Check if a bash argument is set in a script

File varcheck.sh

#!/usr/bin/env bash

if [[ ! -z ${1+x} ]]; then
    echo "var is set to '$1'";
else
    echo "var is unset";
fi

varcheck.sh will output: var is unset
Running varcheck.sh TADA will output: var is set to 'TADA'

Nginx change default user

Default nginx runs on the user www, www-data of something alike.

You can change it. Be sure that you are aware of the security risks!
Don’t change it to a user that has access to sudo (like a pi user)!

In /etc/nginx/nginx.conf on line #1 change the user.

#user www-data;
user deployment;

And change the user for php-fpm (If you’re using php-fpm ?)

Create a file in /etc/php/7.4/fpm/pool.d/ (check the php version)
I suggest something like zzz-custom-user.conf so it’s loaded last. To that file add.

user = deployment
group = deployment
listen.owner = deployment
listen.group = deployment

Next reload everything, agian check php version.

sudo nginx -t && sudo service php7.4-fpm restart && sudo service nginx restart

Finally change the owner of the webfiles

sudo chown pi:pi /var/www/ -R

All done.