====== Linux Cheatsheet ======

[[engineering:computer_science:linux:linux|Linux]] Cheatsheet

===== Jobs: =====

^Command^Description^Syntax^Example^Notes|
|jobs|List jobs running in the background|<code bash>
jobs


</code>       |jobs| |
|bg|Changes a job to the background.|<code bash>
bg %n


</code>       |bg %1|<n> being the value from a job.|
|fg|Changes a job to the foreground.|<code bash>
fg %n


</code>       |fg %2|<n> being the value from a job.|

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===== tmux =====

^Command^Description^Syntax|
|tmux list-sessions|Shows all live tmux sessions|<code>
tmux list-sessions

</code>  |
|tmux attach| \\ Attaches to the last active tmux session. \\  \\ The session can be specified. \\ |<code>
tmux attach

</code><code>
tmux attach-session -t <sessionNumber>

</code>  |
|CTRL+B - D|Dettachs to the current tmux session|<code>
CTRL+B - D

</code>       |
|CTRL+B - %|Creates a New Horizontally Aligned Tab|<code>
CTRL+B - %

</code>       |
|CTRL+B - "|Creates a New Vertically Aligned Tab|<code>
CTRL+B - "

</code>       |
|CTRL+B - Arrows|Moves to existent Tabs|<code>
CTRL+B - Arrows

</code>       |

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===== Disks and File Transfer: =====

^Command^Description^Syntax^Notes|
| \\ scp -r * remoteuser@remoteserver:/remote/folder/  |Copy all files and folders recursively from local to remote|<code>
scp -r * remoteuser@remoteserver:/remote/folder/

</code>       |   |
|du -sh /mnt/zebrabackup01/test  |Shows folder size|<code>
du -sh /mnt/zebrabackup01/test

</code>       | |
|ls|Shows object cont in folder|<code bash>
ls | wc -l


</code>       | |
|<code bash>
du -smh * | sort -nr | head -15


</code>       |List Files by Size in Human Readable Way > Sort and Reverse it > Show Top 15|<code bash>
du -smh * | sort -nr | head -15


</code>       |   |

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===== Administration: =====

^Command^Description^Syntax^Notes|
|ip a \\ **OR** \\ ifconfig|Check your machine IPs|<code bash>
ip a


</code>     <code bash>
ifconfig


</code>       | |
|dmidecode –type memory|Shows the installed memory on your system|<code bash>
dmidecode --type memory


</code>       |   |
|<code bash>
find /var/log -type f -regex ".*\.gz$"
find /var/log -type f -regex ".*\.[0-9]$"


</code>       |Find Rotated and Compressed Logs|<code bash>
find /var/log -type f -regex ".*\.gz$"
find /var/log -type f -regex ".*\.[0-9]$"


</code>       |Add '-delete' to actually delete the files found.  |
|<code bash>
for CLEAN in $(find /var/log/ -type f)
do
    cp /dev/null  $CLEAN
done


</code>       |Empty all Log Files|<code bash>
for CLEAN in $(find /var/log/ -type f)
do
    cp /dev/null  $CLEAN
done


</code>       |Deleting the files can cause issues. Emptying them is safer and recommended.  |
|<code>
sudo !!

</code>       |Re-run last command as root|<code>
nano /etc/example.log
sudo !!

</code>       |   |
|CTRL+x+e  |Opens an editor, to create long / complex commands. Runs on saving|In Terminal: \\ CTRL+x+e \\ ls -l \\ CTRL+X \\ ENTER| |
|fc  |Opens the last command in an editor to make it easier to fix it.|<code>
fc

</code>     | |
|disown -a && exit  |Exit Terminal but leave all processes running|<code>
disown -a && exit

</code>     | |

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