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This is a solution for a , some without swap of some machine setup without swap where you need swap for something without wanting to fiddle with the drive partitions or so.

This is a quick and dirty „short manual“ for based environments (such as , or ).

First run this:

cat > dphys-swap.sh << EOF
#!/bin/bash
#~/up
apt-get install dphys-swapfile
echo "CONF_SWAPSIZE=2048"|tee -a /etc/dphys-swapfile
dphys-swapfile setup
dphys-swapfile swapon
systemctl restart dphys-swapfile.service
systemctl status dphys-swapfile.service
free -h
EOF

This will just create a short with the needed commands to run to get setup and running. Please alter the number 2048 to your need, it is the size of the swap memory that will be setup. The size of the swap should most likely by equal to the real memory installed, sometimes twice the size seems to be a good choice too.

If you don’t know your memory size you can find it out by running the command „free -h“, which will print the size of the physical memory installed and the below this the swap size(s).

After pasting the above code into your shell, which will create a file called „dphys-swap.sh“ in the current folder (you should be in your home folder!!), you need to make the shell script „dphys-swap.sh“ executable by running:

chmod +x dphys-swap.sh

Then you need to run the script like this:

sudo ~/dphys-swap.sh

It will ask for some confirmation(s) to install certain packages.

The last commands will output the status of the systemd service „dphys-swapfile.service“ and the last line will show you the memory and swap size again.

Remark:
In the script above I use „up“, my full update of the system. I just blogged that one too, have a look here.

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… is an easy to use and powerful tool, it can be used to replace part of file name (string1) with some other string. Something one can also do with some „sed“ hack, but this tool is much easier to use, especially for beginners.

You can get all information needed from „rename –help“ (here from Linux Mint):

rename --help
Usage:
    rename [ -h|-m|-V ] [ -v ] [ -n ] [ -f ] [ -e|-E perlexpr]*|perlexpr
    [ files ]

Options:
    -v, -verbose
            Verbose: print names of files successfully renamed.

    -n, -nono
            No action: print names of files to be renamed, but don't rename.

    -f, -force
            Over write: allow existing files to be over-written.

    -h, -help
            Help: print SYNOPSIS and OPTIONS.

    -m, -man
            Manual: print manual page.

    -V, -version
            Version: show version number.

    -e      Expression: code to act on files name.

            May be repeated to build up code (like "perl -e"). If no -e, the
            first argument is used as code.

    -E      Statement: code to act on files name, as -e but terminated by
            ';'.

I did use this tool rename some files that contained the string „www“, which I had to replace with „web“, lets say there were files named like this:

www.example.com-97126.ccd
www.example.com-54852.ccd
www.example.com-87430.ccd
www.example.com-75413.ccd

For Ubuntu, maybe also Debian, based systems I use the following command to rename all above files:

rename -e 's/www/web/' *.ccd

After this the files are now called
web.example.com-….
….

The only problem is, the syntax varies from one Linux distribution to another, so check the syntax before you use rename.

For Arch Linux I found that something like this would work:

rename www web *.ccd

The expression „*.ccd“ defines which files to act on, so this will act on all files that match „*.ccd*, in the example above you could also use „www.example.com-*.ccd“ or something similar.

Main thing I wanted to get out there is, there is an easy tool to batch rename files instead of some complex if-for bash code. Which I tried to use before but failed at.