scripts

Scripts are small programs written in text that Linux can run immediately (without compilation.)

After writing a script in a text editor, save it and make it executable;
e.g

chmod 755 myscript

Here are some handy bash scripts.

Quick Disk Speed Test

There's a copy program called dd that displays speed info by default that we can use;
disktest works in the current directory or you can specify a device e.g
disktest sda1

disktest

#!/bin/bash
if [ `whoami` != root ]; then
    echo Please run as root or sudo; exit
fi
if [ "$1" == "" ]; then
   echo assuming current device and directory
else
   echo device $1
   mkdir /mnt/$1 2> /dev/null
   mount /dev/$1 /mnt/$1
   cd /mnt/$1
fi
echo
echo write-test
sync
dd if=/dev/zero of=test.data bs=8k count=64k
echo

echo read-test
sudo sh -c "echo 3 > /proc/sys/vm/drop_caches"
sync
dd if=test.data of=/dev/null bs=8k count=64k
echo

echo read-write-test
sudo sh -c "echo 3 > /proc/sys/vm/drop_caches"
sync
dd if=test.data of=test.out bs=8k count=32k

echo done.

Quick Mount / Unmount

push <dev> mounts a drive e.g push sda1 the drive is found at /mnt/sda1
pop <dev> un-mounts a drive e.g pop sda1

push

#!/bin/bash
umount /dev/$1 2>/dev/null
mkdir /mnt/$1 2>/dev/null
mount /dev/$1 /mnt/$1 -o uid=batman -o gid=batman
cd /mnt/$1

Activate user permissions and go into the directory.

pop

#!/bin/bash
cd ~
umount /dev/$1

Leave directory and unmount.

CleanUp Trash

cleanup

#!/bin/bash
sudo rm /home/batman/.cache/chromium/Default/Cache/*
sudo rm -r /home/batman/.opera/cache
sudo rm -r /home/batman/.opera/application_cache
sudo rm -r /home/batman/.opera/opcache
sudo rm -r /home/batman/.opera/pstorage
sudo rm -r /home/batman/.opera/vps
sudo rm -r /home/batman/.opera/temporary_downloads

sudo rm /usr/share/icons/gnome/icon-theme.cache
sudo rm /usr/share/app-install/icon-theme.cache
sudo rm /var/log/*.gz
sudo rm /var/log/*.old

sudo apt-get clean
sudo apt-get autoclean
sudo apt-get autoremove -y
sudo rm /var/cache/apt/pkgcache.bin
sudo rm /var/cache/apt/srcpkgcache.bin

This is a script I routinely use to maximise storage.
If you don't use the opea browser, you can delete those lines.

Free Up Memory

freemem

#!/bin/bash

free -m
sync
sudo sh -c "echo 3 > /proc/sys/vm/drop_caches"
sync
free -m

This shows memory before and after dropping the cache.

More Lubuntu Tips