Linux - Cheatsheet

• Ubuntu/Debian
• Resize Filesystem Without Reboot
• Change Swap Size
• Unzip All Files In Directory
• Zip All Files Into Each Individual Zip File

Ubuntu/Debian

Resize Filesystem Without Reboot

1. Toggle some informations about the root filesystem:

df /
# Filesystem     1K-blocks     Used Available Use% Mounted on
# /dev/vda3       71412992 58923184   9039732  87% /

2. /dev/vda3 is the second partition of block device /dev/vda. To size up this partition, you can use the tool parted.

parted /dev/vda resizepart 3 100%
# Warning: Partition /dev/sda2 is being used. Are you sure you want to continue?
# Yes/No? yes
# Information: You may need to update /etc/fstab.

3. After changing size of partition, you have to size up the filsystem too:

resize2fs /dev/vda3
# resize2fs 1.45.5 (07-Jan-2020)
# Filesystem at /dev/vda3 is mounted on /; on-line resizing required
# old_desc_blocks = 4, new_desc_blocks = 9
# The filesystem on /dev/vda3 is now 18019403 (4k) blocks long.

4. This is for checking modifications:

df /
# Filesystem     1K-blocks    Used Available Use% Mounted on
# /dev/vda3       70817420 5253016  62349464   8% /

Change Swap Size

1. Turn off all running swap processes: swapoff -a
2. Resize swap fallocate -l 1G /swapfile (change 1G to the gigabyte size you want it to be)
3. CHMOD swap: chmod 600 /swapfile
4. Make file usable as swap mkswap /swapfile
5. Active the swap file swapon /swapfile

To verify your swap size run the following command and you will see the swap size: free -m

Unzip All Files In Directory

.zip Files

unzip "*.zip"

Alternative for systems that only have 7zip installed.

find /volume1/Emulation/JDownloader/PS2 -type f -iname '*.zip' -execdir 7z x {} ';'

.7z Files

Install 7zip first.

sudo apt install p7zip-full

7za -y x "*.7z" 

Unzip into individual directories

for archive in *.7z; do 7z x -o"`basename \"$archive\" .7z`" "$archive"; done

Zip All Files Into Each Individual Zip File

The solution is pretty easy. If you want to do this for every file, recursively, use find. It will list all files and directories, descending into subdirectories too.

All Subdirectories:

find . -type f -execdir zip '{}.zip' '{}' \;

Explanation:

• The first argument is the directory you want to begin in, .
• Then we will restrict it to find files only (-type f)
• The -execdir option allows us to run a command on each file found, executing it from the file's directory
• This command is evaluated as zip file.txt.zip file.txt, for example, since all occurrences of {} are replaced with the actual file name. This command needs to be ended with \;

---

Of course, find has more options. If instead you just want to stay in your current directory, not descending into subdirectories:

Current Directory Only:

find . -type f -maxdepth 1 -execdir zip '{}.zip' '{}' \;

If you want to restrict it to certain file types, use the -name option (or -iname for case-insensitive matching):

Restrict To Specific Filetypes:

find . -type f -name "*.txt" …

Anything else (including looping with for over the output of ls *) is pretty ugly syntax in my opinion and likely to break, e.g. on files with spaces in their name or due to too many arguments.