Dagimal · July 19, 2022 06:22
diff --git a/fantastic-bash-command b/fantastic-bash-command
 ```sh                                     
 _____         _           _   _     
 |   __|___ ___| |_ ___ ___| |_|_|___ 
 |   __| .'|   |  _| .'|_ -|  _| |  _|
 |__|  |__,|_|_|_| |__,|___|_| |_|___|
                                     
 +++ Bash Command +++

 ```

 # Awesome Bash Commands [![](https://cdn.rawgit.com/sindresorhus/awesome/d7305f38d29fed78fa85652e3a63e154dd8e8829/media/badge.svg)](https://github.com/sindresorhus/awesome)

 > A curated list of awesome [Bash](https://www.gnu.org/software/bash/) useful commands. Inspired by [awesome-shell](https://github.com/alebcay/awesome-shell) and [bash-handbook](https://github.com/denysdovhan/bash-handbook).

 ## Table of Contents
 - [Files and directories](#files-and-directories)
 - [Paths](#paths)
 - [Devices](#devices)
 - [Users and Groups](#users-and-groups)
 - [Date & Time](#date--time)
 - [Network](#network)
 - [Miscellaneous](#miscellaneous)
 - [Other Awesome Lists](#other-awesome-lists)

 ### Files and directories

 #### List files sorted by extension

 ```sh
 ls -l -X
 # Or
 ls -l --sort=extension
 ```

 #### Count number of files within a directory

 ```sh
 ls -1 ./my-directory | wc -l
 ```

 _Note: use `-a` to include also dot files._

 #### Create a symbolic link for one directory or file

 ```sh
 ln -s /var/www/html ~/www
 ln -s ~/my/large/path/file.txt ~/myfile.txt
 ```

 #### Change permissions for a symbolic link only

 ```sh
 chmod -h 770 ~/www
 chown -h www-data:www-data ~/www
 ```

 #### Find octal permissions of one file or directory

 ```sh
 stat -c "%a %n" /var/www/html
 # 770 /var/www/html
 ```

 #### Add sticky permissions to one directory and subdirectories

 ```sh
 find /var/www/html -type d -exec chmod g+s {} \
 ```

 _Note: Any new file created will have the same permissions as the root folder_

 #### Create one empty file in current directory and subdirectories

 ```sh
 find ./my/current/directory -type d -exec touch {}/.gitignore \;
 ```

 #### Delete one specific file of current directory and subdirectories

 ```sh
 find ./my/current/directory -name ".gitignore" -type f -delete
 ```

 #### Delete all content of one directory but except one in specific

 ```sh
 find ./my-directory -mindepth 1 ! -regex '^./my-directory/data\(/.*\)?' -delete
 ```

 #### Copy file content to clipboard
 Copy shell command output to clipboard

 ```sh
 cat myfile.txt | xclip -selection c
 ```

 #### Copy entire directory to destination

 ```sh
 cp -avr /my/current/directory /destination/directory
 # Or
 rsync -av /my/current/directory /destination/directory
 ```

 #### Copy entire directory files only to destination with exclude option

 ```sh
 rsync -har --progress --exclude .git /current/directory/. /destination/directory
 ```

 #### Transfer an entire directory content to a remote destination

 __Note:__ It's necessary to setup a SSH connection. You can use a [SSH Config file](https://www.cyberciti.biz/faq/create-ssh-config-file-on-linux-unix/).

 ```sh
 rsync -hrtpluz --progress --stats my-current-directory/. my-remote-server:/var/data/my-remote-dir
 ```

 Options used above:

 ```sh
 -h,                  output numbers in a human-readable format 
 -r                   recurse into directories
 -t, --times          preserve modification times
 -p, --perms          preserve permissions
 -l, --links          copy symlinks as symlinks
 -u, --update         skip files that are newer on the receiver
 -z, --compress       compress file data during the transfer
 --progress           show progress during transfer
 --stats              give some file-transfer stats
 ```

 #### Show the space usage of file or directory

 Show the space usage of file or directory (recursive) in human readable format.

 ```sh
 du -sh /var/log/dnf.librepo.log
 # 4,1M	/var/log/dnf.librepo.log

 du -sh /var/log
 # 2,2G	/var/log
 ```

 #### Show size of one symbolic link (file or directory)

 ```sh
 du -Hsh $(which dart)
 # 21M	/usr/local/bin/dart
 ```

 #### Show space usage of directories and files ordered by size

 ```sh
 du -sh /var/data/software/app/* | sort -rh
 # 1.1G	/var/data/software/app/backups
 # 223M	/var/data/software/app/logs
 # 125M	/var/data/software/app/attachments
 # 70M	/var/data/software/app/recovery
 # 1.2M	/var/data/software/app/shared-home
 # 592K	/var/data/software/app/viewfile
 # 12K	/var/data/software/app/journal
 # 4.0K	/var/data/software/app/bundled-plugins
 # 0	    /var/data/software/app/lock
 ```

 #### Show top ten of biggest directories

 ```sh
 du -hS /home/user/some/directory | sort -rh | head -10
 # 90G	/home/user/some/directory/big-dir
 # 10G	/home/user/some/directory/subdir/another-big-dir
 # ...
 ```

 #### Delete all files in directory by pattern

 ```sh
 find /usr/local/apache/logs/archive/ -name '*2017.gz' -delete
 ```

 #### Move files by pattern

 _This command move all `*.js` files into `*.ts` files (move equivalent)_

 ```sh
 find src/ -type f -name "*.js" -exec bash -c 'mv {} `echo {} | sed -e "s/.js/.ts/g"`' \;
 ```

 #### Compress files by pattern using tar and gzip

 Command bellow compress a group of files by pattern using tar and gzip compression into a new file like `FILE_NAME.tar.gz`. 
 No sorting guaranteed.

 ```sh
 # Input files:
 # src/file1.log.01
 # src/file1.log.02
 # src/file1.log.03

 find src/ -type f -name "file1.log.*" -exec bash -c "tar cf - {} | gzip -9 > {}.tar.gz" \;

 # Or using find -exec

 find src/ -maxdepth 1 -type f -name "file1.log.*" -exec sh -c "tar cf - {} | gzip -9 > tarballs/{}.tar.gz && echo '{} (compressed)'" \;

 # Output files:
 # src/file1.log.01.tar.gz
 # src/file1.log.02.tar.gz
 # src/file1.log.03.tar.gz
 ```

 #### Optimizing Tar/Gzip archive size by changing content files order

 ```sh
 find directory/* -print | rev | sort | rev | \
      tar --create --no-recursion --files-from - | \
      gzip -c > directory.tar.gz
 ```

 Motivated by https://news.ycombinator.com/item?id=24221498

 **Alternative sorting in ascending way:**

 ```sh
 find . -type f -name  "file1.log.*" | sort -n | xargs -I{} sh -c "tar cf - {} | gzip -9 > {}.tar.gz && echo '{} (compressed)'" \;
 ```

 __Tip:__ Use `-maxdepth` flag in order to limit directory levels finding.

 #### Compress a directory using tar and gzip

 ```sh
 tar -zcvf my_dir.tar.gz my-dir/
 ```

 #### List content of a tar and gzip file without extracting it

 ```sh
 tar -tvf my_dir.tar.gz | less
 ```

 #### Create a temporary directory with prefix

 ```sh
 mktemp -dt "my-prefix"
 ```

 #### Clean temporary directory

 ```sh
 rm -rf /tmp/* /tmp/.*
 ```

 #### Calculate gzip size of one no compressed file

 ```sh
 gzip -c FILENAME.txt | wc -c | awk '{
 if ($1 > 1000 ^ 3) {
  print($1 / (1000 ^ 3)"G")
 } else if ($1 > 1000 ^ 2) {
  print($1 / (1000 ^ 2)"M")
 } else if ($1 > 1000) {
  print($1 / 1000"K")
 } else {
  print($1)"b"
 }}'

 # 560K
 ```

 #### Split out a specific file into more small files by number of lines

 ```sh
 split -d -l 200000 ./big_file.log small_file.log.

 # Output files in current directory:
 # small_file.log.01
 # small_file.log.02
 # small_file.log.03
 # ....
 ```

 _Notes:_

 - `smallfile.log.` is a custom suffix for file names.
 - `200000` is a custom number of lines per file.

 #### Get only the number of lines of one specific file

 ```sh
 wc -l big_file.log | sed -E "s/([a-z\-\_\.]|[[:space:]]*)//g"

 # 9249133
 ```

 ### Paths

 #### Show the full path of a command

 ```sh
 which bash
 # /usr/bin/bash

 which git node
 # /usr/bin/git
 # /usr/bin/node
 ```

 #### Show the resolved path of a symbolic link

 ```sh
 realpath ~/www
 # /usr/share/nginx/html
 ```

 #### Determine the current directory

 ```sh
 pwd
 # /home/my/current/directory
 ```

 ### Devices

 #### Display file system disk space usage with total

 Show the file system disk space usage in human readable format.

 ```sh
 df -h --total
 # Filesystem      Size  Used Avail Use% Mounted on
 # devtmpfs        487M     0  487M   0% /dev
 # tmpfs           497M     0  497M   0% /dev/shm
 # tmpfs           497M  508K  496M   1% /run
 # tmpfs           497M     0  497M   0% /sys/fs/cgroup
 # /dev/vda1        30G  2.7G   26G  10% /
 # tmpfs           100M     0  100M   0% /run/user/0
 # total           2.2T  600G  100G  20% -
 ```

 #### Display system memory information with total

 ```sh
 free -h --total
 #               total        used        free      shared  buff/cache   available
 # Mem:           200G         60G        100G        262M         30G        180G
 # Swap:            0B          0B          0B
 # Total:         200G         60G        100G
 ```

 or

 ```sh
 cat /proc/meminfo
 # MemTotal:       183815530 kB
 # MemFree:        101918660 kB
 # MemAvailable:   123712410 kB
 # ....
 ```

 _Tip: Pipe `grep` to filter your results. E.g `cat /proc/meminfo | grep MemTotal`_

 #### Mount a FAT32 USB device

 ```sh
 mount -t vfat /dev/sdb1 /media/usb
 ```

 #### Increase temporary directory size

 ```sh
 mount -o remount,size=5G /tmp/
 ```

 #### Find out a block device by label

 ```sh
 blkid --label MY_MICROSD
 # /dev/sdc1

 lsblk --output name,serial,uuid,partuuid,label,partlabel $(blkid --label MY_MICROSD)
 # NAME SERIAL UUID          PARTUUID       LABEL        PARTLABEL
 # sdc1        4BGE-7510     ec123nba-02    MY_MICROSD
 ```

 ### Users and Groups

 #### Switch user and execute command immediately

 ```sh
 sudo -Hu root fish
 ```

 #### Add an existing user to existing group

 ```sh
 usermod -a -G ftp john
 ```

 ### Date & Time

 #### Show extended ISO format Date ([ISO 8601](http://en.wikipedia.org/wiki/ISO_8601))

 ```sh
 date "+%Y-%m-%dT%H:%m:%S"
 # 2018-09-13T10:09:26
 ```

 ### Network

 #### Show current IP address

 ```sh
 ifconfig | awk '/<UP,BROADCAST,RUNNING,MULTICAST>/ { getline; print $2 }'
 # or
 ifconfig | grep -E "([0-9]{1,3}\.){3}[0-9]{1,3}" | grep -v 127.0.0.1 | awk '{ print $2 }' | cut -f2 -d: | head -n1
 ```

 ### Miscellaneous

 #### Show GNU/Linux distribution and operating system

 a) Using `hostnamectl`:

 ```sh
 hostnamectl | grep -E "(.+)(System|Kernel|Arch)(.+)"
 #  Operating System: Arch Linux
 #            Kernel: Linux 5.1.7-arch1-1-ARCH
 #      Architecture: x86-64
 ```

 b) Using `cat /etc/os-release`:

 ```sh
 cat /etc/os-release
 # NAME="Arch Linux"
 # PRETTY_NAME="Arch Linux"
 # ID=arch
 # BUILD_ID=rolling
 # ANSI_COLOR="0;36"
 # HOME_URL="https://www.archlinux.org/"
 # DOCUMENTATION_URL="https://wiki.archlinux.org/"
 # SUPPORT_URL="https://bbs.archlinux.org/"
 # BUG_REPORT_URL="https://bugs.archlinux.org/"
 # LOGO=archlinux
 ```

 #### Generate random numbers

 a)

 ```sh
 od -vAn -N64 < /dev/urandom | tr '\n' ' ' | sed "s/ //g" | head -c 32
 # 03121617301002504516642404031105
 ```

 b)

 ```sh
 env LC_CTYPE=C tr -dc "0-9" < /dev/urandom | head -c 32 | xargs
 # 50569696992247151969921987764342
 ```

 _Change `head` value to truncate the result's length._

 #### Generate random alphanumerics

 a) Alphanumeric only

 ```sh
 base64 /dev/urandom | tr -d '/+' | head -c 32 | xargs
 # 3udiq6F74alwcPwXzIDWSnjRYQXcxiyl
 ```

 b) Alphanumeric with a custom chars set

 ```sh
 env LC_CTYPE=C tr -dc "A-Za-z0-9_!@#\$%^&*()-+=" < /dev/urandom | head -c 32 | xargs
 # yiMg^Cha=Zh$6Xh%zDQAyBH1SI6Po(&P
 ```

 _Change `tr -dc` char set to get a custom result._

 #### Generate a random hash

 ```sh
 od -vAn -N64 < /dev/urandom | tr '\n' ' ' | sed "s/ //g" | openssl dgst -sha256 | sed "s/-//g"
 # 7adf57e0a90b32ce0e1f446268dbd62b583c649a2e71a426519c6e9c0006b143
 ```

 _Openssl digest algorithms supported: `md5`, `md4`, `md2`, `sha1`, `sha`, `sha224`, `sha256`, `sha384`, `sha512`, `mdc2` and `ripemd160`_

 #### Generate a random UUID

 ```sh
 uuidgen | tr "[:lower:]" "[:upper:]"
 # D2DA7D0C-ABAA-4866-9C97-61791C9FEC89
 ```

 #### Generate 1 million of unique random phone numbers
 This command generate one million of unique random phone numbers (random permutations) fast using GNU/Linux [shuf](https://www.gnu.org/software/coreutils/manual/html_node/shuf-invocation.html) command.
 Use `sed` command for customize each number format. For example for add some prefix or suffix. Remember `shuf` is not limited to numbers only.

 ```sh
 shuf -i 100000000-999999999 -n 1000000 | sed -e 's/^/51/' > gsm.txt
 ```

 #### Download a file using Curl and get its stats

 These commands below downloads a file using Curl and get its download stats into a `curl-download-stats.log` file.
 Place the script content into a custom file `.sh` and run just it.

 ```sh
 #!/bin/bash

 curl -Skw "\
 CURL download testing\n\
 =====================\n\
 URL:                    %{url_effective}\n\
 Response code:          %{response_code}\n\
 Download size:          %{size_download}B\n\
 Download speed:         %{speed_download}B/s\n\
 Time connect:           %{time_connect}s\n\
 Time name lookup:       %{time_namelookup}s\n\
 Time pretransfer:       %{time_pretransfer}\n\
 Time start transfer:    %{time_starttransfer}s\n\
 Time redirect:          %{time_redirect}s\n\
 Time total:             %{time_total}s\n" \
 -Lo /dev/null --url \
 https://ger.mirror.pkgbuild.com/iso/2020.02.01/archlinux-2020.02.01-x86_64.iso \
 > curl-download-stats.log
 ```

 __Notes:__

 - For get the file into a location just replace `/dev/null` with the corresponding file path.
 - For customize the write-out format take a look at https://ec.haxx.se/usingcurl/usingcurl-verbose/usingcurl-writeout

 ### Other Awesome Lists
 - [awesome-shell](https://github.com/alebcay/awesome-shell)
 - [awesome-fish](https://github.com/jbucaran/awesome-fish)
 - [awesome-zsh](https://github.com/unixorn/awesome-zsh-plugins)

 ## Contributions
 Please check out [the contribution file](contributing.md).

 ## License

 [![CC0](http://i.creativecommons.org/p/zero/1.0/88x31.png)](http://creativecommons.org/publicdomain/zero/1.0/)

 To the extent possible under law, [José Luis Quintana](http://git.io/joseluisq) has waived all copyright and related or neighboring rights to this work.
	```sh
	_____ _ _ _
	\| __\|___ ___\| \|_ ___ ___\| \|_\|_\|___
	\| __\| .'\| \| _\| .'\|_ -\| _\| \| _\|
	\|__\| \|__,\|_\|_\|_\| \|__,\|___\|_\| \|_\|___\|

	+++ Bash Command +++

	```

	# Awesome Bash Commands [![](https://cdn.rawgit.com/sindresorhus/awesome/d7305f38d29fed78fa85652e3a63e154dd8e8829/media/badge.svg)](https://github.com/sindresorhus/awesome)

	> A curated list of awesome [Bash](https://www.gnu.org/software/bash/) useful commands. Inspired by [awesome-shell](https://github.com/alebcay/awesome-shell) and [bash-handbook](https://github.com/denysdovhan/bash-handbook).

	## Table of Contents
	- [Files and directories](#files-and-directories)
	- [Paths](#paths)
	- [Devices](#devices)
	- [Users and Groups](#users-and-groups)
	- [Date & Time](#date--time)
	- [Network](#network)
	- [Miscellaneous](#miscellaneous)
	- [Other Awesome Lists](#other-awesome-lists)

	### Files and directories

	#### List files sorted by extension

	```sh
	ls -l -X
	# Or
	ls -l --sort=extension
	```

	#### Count number of files within a directory

	```sh
	ls -1 ./my-directory \| wc -l
	```

	_Note: use `-a` to include also dot files._

	#### Create a symbolic link for one directory or file

	```sh
	ln -s /var/www/html ~/www
	ln -s ~/my/large/path/file.txt ~/myfile.txt
	```

	#### Change permissions for a symbolic link only

	```sh
	chmod -h 770 ~/www
	chown -h www-data:www-data ~/www
	```

	#### Find octal permissions of one file or directory

	```sh
	stat -c "%a %n" /var/www/html
	# 770 /var/www/html
	```

	#### Add sticky permissions to one directory and subdirectories

	```sh
	find /var/www/html -type d -exec chmod g+s {} \
	```

	_Note: Any new file created will have the same permissions as the root folder_

	#### Create one empty file in current directory and subdirectories

	```sh
	find ./my/current/directory -type d -exec touch {}/.gitignore \;
	```

	#### Delete one specific file of current directory and subdirectories

	```sh
	find ./my/current/directory -name ".gitignore" -type f -delete
	```

	#### Delete all content of one directory but except one in specific

	```sh
	find ./my-directory -mindepth 1 ! -regex '^./my-directory/data\(/.*\)?' -delete
	```

	#### Copy file content to clipboard
	Copy shell command output to clipboard

	```sh
	cat myfile.txt \| xclip -selection c
	```

	#### Copy entire directory to destination

	```sh
	cp -avr /my/current/directory /destination/directory
	# Or
	rsync -av /my/current/directory /destination/directory
	```

	#### Copy entire directory files only to destination with exclude option

	```sh
	rsync -har --progress --exclude .git /current/directory/. /destination/directory
	```

	#### Transfer an entire directory content to a remote destination

	__Note:__ It's necessary to setup a SSH connection. You can use a [SSH Config file](https://www.cyberciti.biz/faq/create-ssh-config-file-on-linux-unix/).

	```sh
	rsync -hrtpluz --progress --stats my-current-directory/. my-remote-server:/var/data/my-remote-dir
	```

	Options used above:

	```sh
	-h, output numbers in a human-readable format
	-r recurse into directories
	-t, --times preserve modification times
	-p, --perms preserve permissions
	-l, --links copy symlinks as symlinks
	-u, --update skip files that are newer on the receiver
	-z, --compress compress file data during the transfer
	--progress show progress during transfer
	--stats give some file-transfer stats
	```

	#### Show the space usage of file or directory

	Show the space usage of file or directory (recursive) in human readable format.

	```sh
	du -sh /var/log/dnf.librepo.log
	# 4,1M /var/log/dnf.librepo.log

	du -sh /var/log
	# 2,2G /var/log
	```

	#### Show size of one symbolic link (file or directory)

	```sh
	du -Hsh $(which dart)
	# 21M /usr/local/bin/dart
	```

	#### Show space usage of directories and files ordered by size

	```sh
	du -sh /var/data/software/app/* \| sort -rh
	# 1.1G /var/data/software/app/backups
	# 223M /var/data/software/app/logs
	# 125M /var/data/software/app/attachments
	# 70M /var/data/software/app/recovery
	# 1.2M /var/data/software/app/shared-home
	# 592K /var/data/software/app/viewfile
	# 12K /var/data/software/app/journal
	# 4.0K /var/data/software/app/bundled-plugins
	# 0 /var/data/software/app/lock
	```

	#### Show top ten of biggest directories

	```sh
	du -hS /home/user/some/directory \| sort -rh \| head -10
	# 90G /home/user/some/directory/big-dir
	# 10G /home/user/some/directory/subdir/another-big-dir
	# ...
	```

	#### Delete all files in directory by pattern

	```sh
	find /usr/local/apache/logs/archive/ -name '*2017.gz' -delete
	```

	#### Move files by pattern

	_This command move all `.js` files into `.ts` files (move equivalent)_

	```sh
	find src/ -type f -name "*.js" -exec bash -c 'mv {} `echo {} \| sed -e "s/.js/.ts/g"`' \;
	```

	#### Compress files by pattern using tar and gzip

	Command bellow compress a group of files by pattern using tar and gzip compression into a new file like `FILE_NAME.tar.gz`.
	No sorting guaranteed.

	```sh
	# Input files:
	# src/file1.log.01
	# src/file1.log.02
	# src/file1.log.03

	find src/ -type f -name "file1.log.*" -exec bash -c "tar cf - {} \| gzip -9 > {}.tar.gz" \;

	# Or using find -exec

	find src/ -maxdepth 1 -type f -name "file1.log.*" -exec sh -c "tar cf - {} \| gzip -9 > tarballs/{}.tar.gz && echo '{} (compressed)'" \;

	# Output files:
	# src/file1.log.01.tar.gz
	# src/file1.log.02.tar.gz
	# src/file1.log.03.tar.gz
	```

	#### Optimizing Tar/Gzip archive size by changing content files order

	```sh
	find directory/* -print \| rev \| sort \| rev \| \
	tar --create --no-recursion --files-from - \| \
	gzip -c > directory.tar.gz
	```

	Motivated by https://news.ycombinator.com/item?id=24221498

	Alternative sorting in ascending way:

	```sh
	find . -type f -name "file1.log.*" \| sort -n \| xargs -I{} sh -c "tar cf - {} \| gzip -9 > {}.tar.gz && echo '{} (compressed)'" \;
	```

	__Tip:__ Use `-maxdepth` flag in order to limit directory levels finding.

	#### Compress a directory using tar and gzip

	```sh
	tar -zcvf my_dir.tar.gz my-dir/
	```

	#### List content of a tar and gzip file without extracting it

	```sh
	tar -tvf my_dir.tar.gz \| less
	```

	#### Create a temporary directory with prefix

	```sh
	mktemp -dt "my-prefix"
	```

	#### Clean temporary directory

	```sh
	rm -rf /tmp/* /tmp/.*
	```

	#### Calculate gzip size of one no compressed file

	```sh
	gzip -c FILENAME.txt \| wc -c \| awk '{
	if ($1 > 1000 ^ 3) {
	print($1 / (1000 ^ 3)"G")
	} else if ($1 > 1000 ^ 2) {
	print($1 / (1000 ^ 2)"M")
	} else if ($1 > 1000) {
	print($1 / 1000"K")
	} else {
	print($1)"b"
	}}'

	# 560K
	```

	#### Split out a specific file into more small files by number of lines

	```sh
	split -d -l 200000 ./big_file.log small_file.log.

	# Output files in current directory:
	# small_file.log.01
	# small_file.log.02
	# small_file.log.03
	# ....
	```

	_Notes:_

	- `smallfile.log.` is a custom suffix for file names.
	- `200000` is a custom number of lines per file.

	#### Get only the number of lines of one specific file

	```sh
	wc -l big_file.log \| sed -E "s/([a-z\-\_\.]\|[[:space:]]*)//g"

	# 9249133
	```

	### Paths

	#### Show the full path of a command

	```sh
	which bash
	# /usr/bin/bash

	which git node
	# /usr/bin/git
	# /usr/bin/node
	```

	#### Show the resolved path of a symbolic link

	```sh
	realpath ~/www
	# /usr/share/nginx/html
	```

	#### Determine the current directory

	```sh
	pwd
	# /home/my/current/directory
	```

	### Devices

	#### Display file system disk space usage with total

	Show the file system disk space usage in human readable format.

	```sh
	df -h --total
	# Filesystem Size Used Avail Use% Mounted on
	# devtmpfs 487M 0 487M 0% /dev
	# tmpfs 497M 0 497M 0% /dev/shm
	# tmpfs 497M 508K 496M 1% /run
	# tmpfs 497M 0 497M 0% /sys/fs/cgroup
	# /dev/vda1 30G 2.7G 26G 10% /
	# tmpfs 100M 0 100M 0% /run/user/0
	# total 2.2T 600G 100G 20% -
	```

	#### Display system memory information with total

	```sh
	free -h --total
	# total used free shared buff/cache available
	# Mem: 200G 60G 100G 262M 30G 180G
	# Swap: 0B 0B 0B
	# Total: 200G 60G 100G
	```

	or

	```sh
	cat /proc/meminfo
	# MemTotal: 183815530 kB
	# MemFree: 101918660 kB
	# MemAvailable: 123712410 kB
	# ....
	```

	_Tip: Pipe `grep` to filter your results. E.g `cat /proc/meminfo \| grep MemTotal`_

	#### Mount a FAT32 USB device

	```sh
	mount -t vfat /dev/sdb1 /media/usb
	```

	#### Increase temporary directory size

	```sh
	mount -o remount,size=5G /tmp/
	```

	#### Find out a block device by label

	```sh
	blkid --label MY_MICROSD
	# /dev/sdc1

	lsblk --output name,serial,uuid,partuuid,label,partlabel $(blkid --label MY_MICROSD)
	# NAME SERIAL UUID PARTUUID LABEL PARTLABEL
	# sdc1 4BGE-7510 ec123nba-02 MY_MICROSD
	```

	### Users and Groups

	#### Switch user and execute command immediately

	```sh
	sudo -Hu root fish
	```

	#### Add an existing user to existing group

	```sh
	usermod -a -G ftp john
	```

	### Date & Time

	#### Show extended ISO format Date ([ISO 8601](http://en.wikipedia.org/wiki/ISO_8601))

	```sh
	date "+%Y-%m-%dT%H:%m:%S"
	# 2018-09-13T10:09:26
	```

	### Network

	#### Show current IP address

	```sh
	ifconfig \| awk '/<UP,BROADCAST,RUNNING,MULTICAST>/ { getline; print $2 }'
	# or
	ifconfig \| grep -E "([0-9]{1,3}\.){3}[0-9]{1,3}" \| grep -v 127.0.0.1 \| awk '{ print $2 }' \| cut -f2 -d: \| head -n1
	```

	### Miscellaneous

	#### Show GNU/Linux distribution and operating system

	a) Using `hostnamectl`:

	```sh
	hostnamectl \| grep -E "(.+)(System\|Kernel\|Arch)(.+)"
	# Operating System: Arch Linux
	# Kernel: Linux 5.1.7-arch1-1-ARCH
	# Architecture: x86-64
	```

	b) Using `cat /etc/os-release`:

	```sh
	cat /etc/os-release
	# NAME="Arch Linux"
	# PRETTY_NAME="Arch Linux"
	# ID=arch
	# BUILD_ID=rolling
	# ANSI_COLOR="0;36"
	# HOME_URL="https://www.archlinux.org/"
	# DOCUMENTATION_URL="https://wiki.archlinux.org/"
	# SUPPORT_URL="https://bbs.archlinux.org/"
	# BUG_REPORT_URL="https://bugs.archlinux.org/"
	# LOGO=archlinux
	```

	#### Generate random numbers

	a)

	```sh
	od -vAn -N64 < /dev/urandom \| tr '\n' ' ' \| sed "s/ //g" \| head -c 32
	# 03121617301002504516642404031105
	```

	b)

	```sh
	env LC_CTYPE=C tr -dc "0-9" < /dev/urandom \| head -c 32 \| xargs
	# 50569696992247151969921987764342
	```

	_Change `head` value to truncate the result's length._

	#### Generate random alphanumerics

	a) Alphanumeric only

	```sh
	base64 /dev/urandom \| tr -d '/+' \| head -c 32 \| xargs
	# 3udiq6F74alwcPwXzIDWSnjRYQXcxiyl
	```

	b) Alphanumeric with a custom chars set

	```sh
	env LC_CTYPE=C tr -dc "A-Za-z0-9_!@#\$%^&*()-+=" < /dev/urandom \| head -c 32 \| xargs
	# yiMg^Cha=Zh$6Xh%zDQAyBH1SI6Po(&P
	```

	_Change `tr -dc` char set to get a custom result._

	#### Generate a random hash

	```sh
	od -vAn -N64 < /dev/urandom \| tr '\n' ' ' \| sed "s/ //g" \| openssl dgst -sha256 \| sed "s/-//g"
	# 7adf57e0a90b32ce0e1f446268dbd62b583c649a2e71a426519c6e9c0006b143
	```

	_Openssl digest algorithms supported: `md5`, `md4`, `md2`, `sha1`, `sha`, `sha224`, `sha256`, `sha384`, `sha512`, `mdc2` and `ripemd160`_

	#### Generate a random UUID

	```sh
	uuidgen \| tr "[:lower:]" "[:upper:]"
	# D2DA7D0C-ABAA-4866-9C97-61791C9FEC89
	```

	#### Generate 1 million of unique random phone numbers
	This command generate one million of unique random phone numbers (random permutations) fast using GNU/Linux [shuf](https://www.gnu.org/software/coreutils/manual/html_node/shuf-invocation.html) command.
	Use `sed` command for customize each number format. For example for add some prefix or suffix. Remember `shuf` is not limited to numbers only.

	```sh
	shuf -i 100000000-999999999 -n 1000000 \| sed -e 's/^/51/' > gsm.txt
	```

	#### Download a file using Curl and get its stats

	These commands below downloads a file using Curl and get its download stats into a `curl-download-stats.log` file.
	Place the script content into a custom file `.sh` and run just it.

	```sh
	#!/bin/bash

	curl -Skw "\
	CURL download testing\n\
	=====================\n\
	URL: %{url_effective}\n\
	Response code: %{response_code}\n\
	Download size: %{size_download}B\n\
	Download speed: %{speed_download}B/s\n\
	Time connect: %{time_connect}s\n\
	Time name lookup: %{time_namelookup}s\n\
	Time pretransfer: %{time_pretransfer}\n\
	Time start transfer: %{time_starttransfer}s\n\
	Time redirect: %{time_redirect}s\n\
	Time total: %{time_total}s\n" \
	-Lo /dev/null --url \
	https://ger.mirror.pkgbuild.com/iso/2020.02.01/archlinux-2020.02.01-x86_64.iso \
	> curl-download-stats.log
	```

	__Notes:__

	- For get the file into a location just replace `/dev/null` with the corresponding file path.
	- For customize the write-out format take a look at https://ec.haxx.se/usingcurl/usingcurl-verbose/usingcurl-writeout

	### Other Awesome Lists
	- [awesome-shell](https://github.com/alebcay/awesome-shell)
	- [awesome-fish](https://github.com/jbucaran/awesome-fish)
	- [awesome-zsh](https://github.com/unixorn/awesome-zsh-plugins)

	## Contributions
	Please check out [the contribution file](contributing.md).

	## License

	[![CC0](http://i.creativecommons.org/p/zero/1.0/88x31.png)](http://creativecommons.org/publicdomain/zero/1.0/)

	To the extent possible under law, [José Luis Quintana](http://git.io/joseluisq) has waived all copyright and related or neighboring rights to this work.
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