Linux is a family of open-source Unix-like operating systems based on the Linux kernel. Some of the most popular Linux distributions include Debian, Fedora, and Ubuntu.

linux - View a text file at the command line

View a text file at the command line

To view the first lines of a text file, use the head command. head file.txt = show first 10 lines of filehead -25 file.txt = show first 25 lines of file To view the last lines of a text file, use the tail command. tail...

linux - The root of Linux

The root of Linux

Linux        Linux is a collective name for a class of Unix computer operating systems. The name of the kernel of the Linux operating system is also “Linux”. The Linux operating system is also...

linux - Convert spaces to underscores using a script

Convert spaces to underscores using a script

I had several files that had spaces in their names and I wanted to convert those spaces to underscores. Here’s how I did it. If you don’t have one already, make a bin directory in your home directory: cd mkdir bin In...

linux - More or Less

More or Less


ls | less

Commands to use with less:

space = move ahead a pageb = move back a pageq = quit less

linux - I can't remember the root password!

I can’t remember the root password!

When the LILO: prompt appears (or boot: prompt if you inserted a boot disk), enter: linux -s or linux single When the bash# prompt appears, enter: passwd This will then prompt you for a new root password, without asking for the old one...

linux - Symbolic/soft links & hard 🔗 links

Symbolic/soft links & hard 🔗 links

Soft links Pointers to programs, files, or directories located elsewhere (just like Windows shortcuts)If the original program, file, or directory is renamed, moved, or deleted, the soft link is broken. If you type ls -F you can see...

linux - Memory information

Memory information

Run at the command line:

cat /proc/meminfo = memory usage information

free = how much memory is currently unused

image 14 - ✔️ Spell check documents in Linux using ispell

✔️ Spell check documents in Linux using ispell

You should really only run this command on text documents, not binary (Word, StarOffice, etc.) documents. At the command line, enter: ispell <document name> The following screen will appear highlighting the word with spell errors and...

linux - Installing vs. Upgrading RPM

Installing vs. Upgrading RPM

What’s the difference between installing and upgrading an RPM? And what happens if you upgrade even though you haven’t installed first? If you install an upgrade, typically what happens is that the software is now installed if it...

windows 10 2018 insider wallpaper - Ports


Parallel ports

Windows uses lpt1, lpt2, & lpt3.Linux uses /dev/lp0, /dev/lp1, & /dev/lp2.

Serial ports

Windows uses com1, com2, & so on.Linux uses /dev/ttyS0, /dev/ttyS1, & so on.