diff --git a/.github/README.md b/.github/README.md
index efd77982..ac54e35c 100644
--- a/.github/README.md
+++ b/.github/README.md
@@ -1,6 +1,6 @@
 cheatsheets
 ===========
-This repository contains community-sourced cheatsheets to be used with
+This repository is fork of [cheatsheets][] cause the old repo has no update for long time. It contains community-sourced cheatsheets to be used with
 [cheat][] and similar applications.
 
 ### Format ###
@@ -27,6 +27,9 @@ parameter placeholders. In edge-cases where that syntax may cause confusion, it
 is permissible to use placeholder values (`foo.txt`, `example.com`, etc.) as
 necessary.
 
+### TODO ###
+See [here](../TODO.md)
+
 ### License ###
 Cheatsheets are licensed under [Creative Commons CC0 1.0][cc0]. See
 [LICENSE.txt][] for the full license text.
@@ -36,3 +39,4 @@ Cheatsheets are licensed under [Creative Commons CC0 1.0][cc0]. See
 [cc0]: https://creativecommons.org/publicdomain/zero/1.0/legalcode
 [cheat]:  https://github.com/cheat/cheat
 [docopt]: http://docopt.org
+[cheatsheets]: https://github.com/cheat/cheatsheets
\ No newline at end of file
diff --git a/TODO.md b/TODO.md
new file mode 100644
index 00000000..cd07bf28
--- /dev/null
+++ b/TODO.md
@@ -0,0 +1,7 @@
+# TODO:
+
+- fallocate
+- ftp, lftp
+- hostname
+- htop
+- locate
\ No newline at end of file
diff --git a/alias b/alias
index 76eb813b..c5604619 100644
--- a/alias
+++ b/alias
@@ -6,3 +6,8 @@ alias ll='ls -l'
 
 # To remove alias:
 unalias ll
+
+# Add permanent aliasses
+# bash: ~/.bashrc
+# fish: ~/.config/fish/config.fish
+# zsh: ~/.zshrc
\ No newline at end of file
diff --git a/aptss b/aptss
new file mode 100644
index 00000000..1a90dc74
--- /dev/null
+++ b/aptss
@@ -0,0 +1,42 @@
+---
+tags: [ packaging ]
+---
+# To find packages matching <phrase>:
+aptss search <phrase>
+
+# To show information on a package:
+aptss show <package>
+
+# To fetch package list:
+aptss update
+
+# To download and install the updates and (UNLIKE aptss-get) install new necessary packages:
+aptss upgrade
+
+# To download and install the updates AND install new necessary packages
+# AND remove packages that stand in the way of the upgrade - use with caution:
+aptss dist-upgrade
+
+# To perform a full system upgrade:
+aptss update && aptss upgrade
+
+# To install package(s):
+aptss install <package>...
+
+# To uninstall package(s):
+aptss remove <package>...
+
+# To remove automatically all unused packages:
+aptss autoremove
+
+# To list dependencies of a package:
+aptss depends <package>...
+
+# To remove packages and delete their config files:
+aptss purge <package>...
+
+# To list all packages installed:
+aptss list --installed
+
+---
+aptss is a wrapper of apt-fast and apt in order to accelerate package installation and download for spark app store and linuxdeepin
\ No newline at end of file
diff --git a/bash b/bash
index 5097eac0..2284f9eb 100644
--- a/bash
+++ b/bash
@@ -1,6 +1,6 @@
 # To implement a for loop:
 for file in *;
-do 
+do
     echo $file found;
 done
 
diff --git a/chmod b/chmod
index 3af8ad6a..48fe5de6 100644
--- a/chmod
+++ b/chmod
@@ -2,7 +2,7 @@
 chmod a+x myscript.sh
 
 # Set user to read/write/execute, group/global to read only (myscript.sh), symbolic mode
-chmod u=rwx, go=r myscript.sh 
+chmod u=rwx, go=r myscript.sh
 
 # Remove write from user/group/global (myscript.sh), symbolic mode
 chmod a-w myscript.sh
diff --git a/conda b/conda
index a525a12a..135dd080 100644
--- a/conda
+++ b/conda
@@ -7,7 +7,7 @@ conda env list
 # To initialise an environment
 conda create --name <environment_name>
 
-# To initialise an environment with python3.10 
+# To initialise an environment with python3.10
 conda create --name <environment_name> python=3.10
 
 # To install from a file
diff --git a/curl b/curl
index 772de7f1..2c6e32f9 100644
--- a/curl
+++ b/curl
@@ -35,7 +35,7 @@ curl http://ifconfig.me/all.json
 curl --limit-rate 1000B -O <outfile>
 
 # To get your global IP:
-curl httpbin.org/ip 
+curl httpbin.org/ip
 
 # To get only the HTTP status code:
 curl -o /dev/null -w '%{http_code}\n' -s -I URL
diff --git a/docker b/docker
index 178262f3..7433343b 100644
--- a/docker
+++ b/docker
@@ -4,6 +4,9 @@ docker -d
 # To build a docker image:
 docker build -t <image-tag-name> <path-of-Dockerfile>
 
+# To build a docker image with specific dockerfile name:
+docker build -t <image-tag-name> -f <path-and-name-of-dockerfile> <path-of-Dockerfile>
+
 # To start a container with an interactive shell:
 docker run -ti <image-name> /bin/bash
 
@@ -13,6 +16,9 @@ docker run -d <image-name>
 # To "shell" into a running container (docker-1.3+):
 docker exec -ti <container-name> bash
 
+# To exec some command inside container:
+docker exec <container-name> ping 8.8.8.8
+
 # To inspect a running container:
 docker inspect <container-name> (or <container-id>)
 
@@ -22,8 +28,11 @@ docker inspect --format {{.State.Pid}} <container-name-or-id>
 # To list (and pretty-print) the current mounted volumes for a container:
 docker inspect --format='{{json .Volumes}}' <container-id> | python -mjson.tool
 
-# To copy files/folders between a container and your host:
-docker cp foo.txt mycontainer:/foo.txt
+# To copy a file from the running container to host mechine:
+docker cp <container-id>:<path/to/file> <host/copy/path>
+
+# To copy a file from host mechine to the running container:
+docker cp <host/copy/path> <container-id>:<path/to/file>
 
 # To list currently running containers:
 docker ps
@@ -31,6 +40,9 @@ docker ps
 # To list all containers:
 docker ps -a
 
+# To list all container in format: Name, Image, Status, Port
+docker container ls -a --format "table {{.Names}}\t{{.Image}}\t{{.Status}}\t{{.Ports}}"
+
 # To remove all stopped containers:
 docker container prune
 
@@ -46,6 +58,9 @@ docker image ls -q
 # To remove all untagged images:
 docker rmi $(docker images | grep "^<none>" | awk '{print $3}')
 
+# To remove all images:
+for image in $(docker image ls --format "table {{.Repository}}:{{.Tag}}"); do docker image rm -f $image ; done
+
 # To remove all volumes not used by at least one container:
 docker volume prune
 
@@ -97,8 +112,5 @@ docker run -v <volume-name>:<folder-path-in-container> <image>
 # To link current folder between host and container for development:
 docker run <image-name> -v $(pwd):<folder-path-in-container> <image>
 
-# To copy a file from the running container to host mechine:
-docker cp <container-id>:<path/to/file> <host/copy/path>
-
-# To copy a file from host mechine to the running container:
-docker cp <host/copy/path> <container-id>:<path/to/file>
+# To clean-up docker environment (remove all images, unused containers, volumes, networks)
+docker system prune -af
\ No newline at end of file
diff --git a/du b/du
index d391127f..51bbdba7 100644
--- a/du
+++ b/du
@@ -12,7 +12,7 @@ du -shL
 du -h --apparent-size
 
 # To sort directories/files by size (human-readable):
-du -sh * | sort -rh 
+du -sh * | sort -rh
 
 # To list the 20 largest files and folders under the current working directory:
 du -ma | sort -nr | head -n 20
diff --git a/dwm b/dwm
index ec89bb5d..eaf6560b 100644
--- a/dwm
+++ b/dwm
@@ -2,78 +2,78 @@ Basic
 =====
 # launch terminal.
 [Shift]+[Mod]+[Enter]
-   
+
 # show/hide bar.
-[Mod]+[b]               
+[Mod]+[b]
 
 # dmenu for running programs like the x#www#browser.
-[Mod]+[p]               
+[Mod]+[p]
 
  # push acive window from stack to master, or pulls last used window from stack onto master.
-[Mod]+[Enter]          
+[Mod]+[Enter]
 
  # focus on next/previous window in current tag.
-[Mod] + [j / k]        
+[Mod] + [j / k]
 
  # increases / decreases master size.
-[Mod] + [h / l]        
+[Mod] + [h / l]
 
 
 Navigation
 ==========
 # moves your focus to tag 2.
-[Mod]+[2]      
+[Mod]+[2]
 
 # move active window to the 2 tag.
-[Shift]+[Mod]+[2]      
+[Shift]+[Mod]+[2]
 
  # increases / decreases number of windows on master
-[Mod] + [i / d]        
+[Mod] + [i / d]
 
 # move focus between screens (multi monitor setup)
-[Mod] + [, / .]        
+[Mod] + [, / .]
 
 # move active window to different screen.
-[Shift]+[Mod]+[, / .]   
+[Shift]+[Mod]+[, / .]
 
 # view all windows on screen.
-[Mod]+[0]               
+[Mod]+[0]
 
 # make focused window appear on all tags.
-[Shift]+[Mod]+[0]       
+[Shift]+[Mod]+[0]
 
 # kill active window.
-[Shift]+[Mod]+[c]      
+[Shift]+[Mod]+[c]
 
 # quit dwm cleanly.
-[Shift]+[Mod]+[q]       
+[Shift]+[Mod]+[q]
 
 
 Layout
 ======
 # tiled mode. []=
-[Mod]+[t]               
+[Mod]+[t]
 
 # floating mode. ><>
-[Mod]+[f]               
+[Mod]+[f]
 
 # monocle mode. [M] (single window fullscreen)
-[Mod]+[m]              
+[Mod]+[m]
 
 
 Floating
 ========
 # to resize the floating window.
-[Mod]+[R M B]           
+[Mod]+[R M B]
 
 # to move the floating window around.
-[Mod]+[L M B]           
+[Mod]+[L M B]
 
 # toggles to the previous layout mode.
-[Mod]+[Space]           
+[Mod]+[Space]
 
 # to make an individual window float.
-[Mod]+[Shift]+[Space]  
+[Mod]+[Shift]+[Space]
 
 # to make an individual window un#float.
-[Mod]+[M M B]           
+[Mod]+[M M B]
diff --git a/ed b/ed
index a4635b82..ef8c3c9b 100644
--- a/ed
+++ b/ed
@@ -8,11 +8,11 @@ tags: [ ed ]
 :q              quit
 :Q              quit without saving changes
 :f {name}       change buffer name
-:w              write to file using current buffer name 
+:w              write to file using current buffer name
 :w {file}       write buffer to new file
 :wq             write buffer to existing file and exit
 
-# Line-oriented addressing and movement 
+# Line-oriented addressing and movement
 #   `ed' uses line addresses to move around and operate within a buffer
 #   Move to or operate on single lines by entering the line number
 #   Move to or operate on ranges of lines using comma-separated values
@@ -53,12 +53,12 @@ r !{command}    read output of {command} into buffer after current line
 e test.txt                      edit file "test.txt"
 45                              `ed' returns character count as confirmation
 1,3n                            display lines 1 through 3 with line numbers
-1    This is line 1           
+1    This is line 1
 2    This is line 2
 3    This is line 3
 2c                              change line 2
 I am typing a new line 2
-.                               end active edit 
+.                               end active edit
 1,3n                            display lines 1 thorugh 3 with line numbers
 1    This is line 1
 2    I am typing a new line 2
@@ -71,7 +71,7 @@ wq                              write file "test.txt" and exit
 g/foo/          search all lines for `foo' and display matching lines
 g/foo/n         search all lines for `foo'; display with line numbers
 
-4,9/foo/        search lines 1 through 5 for `foo' and display matches 
+4,9/foo/        search lines 1 through 5 for `foo' and display matches
 4,9/foo/n       search lines 1 through 5 for `foo'; display with line numbers
 
 # Replace
diff --git a/emacs b/emacs
index 88f3f6ee..32a02ba0 100644
--- a/emacs
+++ b/emacs
@@ -36,7 +36,7 @@
   Run command in the scratch buffer               C-x C-e
 
 # Navigation ( backward / forward )
-  
+
   Character-wise                                  C-b , C-f
   Word-wise                                       M-b  , M-f
   Line-wise                                       C-p , C-n
diff --git a/ethtool b/ethtool
index 355e5c2c..a3439f29 100644
--- a/ethtool
+++ b/ethtool
@@ -1,6 +1,6 @@
 ---
 syntax: bash
-tags: [networking] 
+tags: [networking]
 ---
 # To show statistics for the selected interface:
 ethtool -S <interface>
diff --git a/ffmpeg b/ffmpeg
index 60d10ac9..c58fe1d5 100644
--- a/ffmpeg
+++ b/ffmpeg
@@ -39,5 +39,8 @@ cat mylist.txt
 file '/path/to/file1'
 file '/path/to/file2'
 file '/path/to/file3'
-    
+
 ffmpeg -f concat -safe 0 -i mylist.txt -c copy output.mp4
+
+# To change INPUT's FPS to 30 and save as OUTPUT (https://trac.ffmpeg.org/wiki/ChangingFrameRate)
+ffmpeg -i <in-video.ext> -filter:v fps=fps=30 <out-video.ext>
\ No newline at end of file
diff --git a/find b/find
index a02b1aa7..2a05cf5d 100644
--- a/find
+++ b/find
@@ -32,6 +32,7 @@ find ./path/ -name '*.txt' -exec cat '{}' \;
 
 # To find files with extension '.txt' and look for a string into them:
 find ./path/ -name '*.txt' | xargs grep 'string'
+find ./path/ -name '*.txt' -exec grep -nrH 'string' {} \;
 
 # To find files with size bigger than 5 Mebibyte and sort them by size:
 find . -size +5M -type f -print0 | xargs -0 ls -Ssh | sort -z
@@ -61,10 +62,7 @@ find . -type f -samefile MY_FILE_HERE 2>/dev/null
 find . -type f -exec chmod 644 {} \;
 
 # To find all files changed in last 2 days:
-find . -type f -ctime -48h
 find . -type f -ctime -2
-# Or created in last 2 days:
-find . -type f -Btime -2
 # Or accessed in last 2 days:
 find . -type f -atime -2
 
diff --git a/for b/for
index e9309eb7..fe362e51 100644
--- a/for
+++ b/for
@@ -1,38 +1,36 @@
 # basic loop
-for i in 1 2 3 4 5 6 7 8 9 10
-do
+for i in 1 2 3 4 5 6 7 8 9 10; do
   echo $i
 done
 
 # loop ls command results
-for var in `ls -alF`
-do
+for var in $(ls -alF); do
   echo $var
 done
 
 # loop over all the JPG files in the current directory
-for jpg_file in *.jpg
-do
+for jpg_file in *.jpg; do
   echo $jpg_file
 done
 
 # loop specified number of times
-for i in `seq 1 10`
-do
+for i in $(seq 1 10); do
   echo $i
 done
 
 # same as above, but as one-liner
-for i in `seq 1 10`; do echo $i; done
+for i in $(seq 1 10); do echo $i; done
 
 # loop specified number of times: the C/C++ style
-for ((i=1;i<=10;++i))
-do
+for ((i = 1; i <= 10; ++i)); do
   echo $i
 done
 
 # loop specified number of times: the brace expansion
-for i in {1..10}
-do
+for i in {1..10}; do
   echo $i
 done
+
+# loop array of strings
+string=("a" "b")
+for char in "${string[@]}"; do echo "$char"; done
diff --git a/fzf b/fzf
index d872599d..7f5b5b28 100644
--- a/fzf
+++ b/fzf
@@ -19,7 +19,7 @@ fzf --preview "file {}"
 # Find files from find command and preview it with fzf
 find . -type f -name "*.txt" | fzf --preview "head {}"
 
-# Display border around fzf output 
+# Display border around fzf output
 fzf --border sharp
 
 # Output only selected files and pipe it to a file
diff --git a/git b/git
index 15a88286..e59a3c58 100644
--- a/git
+++ b/git
@@ -14,6 +14,9 @@ git config --global color.ui true
 # To stage all changes for commit:
 git add --all
 
+# To unstage some changes in file/folder (Undo `git add` command):
+git reset file-name/folder-name
+
 # To stash changes locally, this will keep the changes in a separate changelist
 # called stash and the working directory is cleaned. You can apply changes
 # from the stash anytime
@@ -54,6 +57,9 @@ git filter-branch --env-filter \
 # To remove staged and working directory changes:
 git reset --hard
 
+# To go 1 commits back & keep staged changes:
+git reset --soft HEAD~1
+
 # To go 2 commits back:
 git reset --hard HEAD~2
 
diff --git a/go b/go
index fe9c14ee..3c8885ba 100644
--- a/go
+++ b/go
@@ -90,7 +90,7 @@ go test -v -run=^TestFooBar$/^Baz$ .
 go test -short ./...
 
 # Handy flag - don't run further tests after a failure.
-go test -failfast ./... 
+go test -failfast ./...
 
 
 # Test all module dependencies.
@@ -104,7 +104,7 @@ go test -run=^TestFooBar$ -count=500 .
 go fix ./...
 
 # Create a new Github issue for Go's standard library
-go bug 
+go bug
 
 
 # Running and Comparing Benchmarks
diff --git a/gpg b/gpg
index 11de2323..d4821493 100644
--- a/gpg
+++ b/gpg
@@ -159,11 +159,11 @@
     gpg -K
 
   Should show sec# instead of just sec.
-  
+
 # High-quality options for gpg for symmetric (secret key) encryption
-  This is what knowledgable people consider a good set of options for 
+  This is what knowledgable people consider a good set of options for
   symmetric encryption with gpg to give you a high-quality result.
-  
+
   gpg \
     --symmetric \
     --cipher-algo aes256 \
@@ -179,7 +179,7 @@
     --no-symkey-cache \
     --output somefile.gpg \
     somefile # to encrypt
-    
+
   gpg \
     --decrypt \
     --pinentry-mode loopback \
diff --git a/gyb b/gyb
index 2fe9f8ac..c5333f3d 100644
--- a/gyb
+++ b/gyb
@@ -1,7 +1,7 @@
 # To estimate the number and the size of all mails on youremail@gmail.com
 gyb --email youremail@gmail.com --action estimate
 
-# To backup from youremail@gmail.com to your local-folder 
+# To backup from youremail@gmail.com to your local-folder
 gyb --email youremail@gmail.com --action backup --local-folder "~/MyLocalFolder/"
 
 # To backup from youremail@gmail.com only important or starred emails to the
@@ -9,4 +9,4 @@ gyb --email youremail@gmail.com --action backup --local-folder "~/MyLocalFolder/
 gyb --email youremail@gmail.com --search "is:important OR is:starred"
 
 # To restore from your local-folder to youremail@gmail.com
-gyb --email youremail@gmail.com --action restore --local-folder "~/MyLocalFolder/" 
+gyb --email youremail@gmail.com --action restore --local-folder "~/MyLocalFolder/"
diff --git a/helix b/helix
new file mode 100644
index 00000000..699a9409
--- /dev/null
+++ b/helix
@@ -0,0 +1,57 @@
+---
+
+tags:
+  - helix
+
+---
+
+# File management
+
+:reload         reload file
+:q              quit
+:q!             quit without saving changes
+:w              write file
+:w {file}       write new file
+:x              write file and exit
+
+# Movement
+
+    k
+  h   l         basic motion
+    j
+
+gg              go to first line in file
+G               go to end of file
+
+# Text selection
+
+v               enter selection mode
+w               to next word start
+W               to next whitespace
+e               to next word end
+E               to next whitespace-delimited word end
+b               to previous start of word
+B               to provious start of whitespace-delimited word
+x               whole line
+
+# Insertion
+
+a               append after the cursor
+A               append at the end of the line
+i               insert before the cursor
+I               insert at the beginning of the line
+o               create a new line under the cursor
+O               create a new line above the cursor
+R               enter insert mode but replace instead of inserting chars
+c               enter insert mode, removing char under cursor
+
+# Editing
+
+u               undo
+xy              yank (copy) a line
+v{motion}y      yank text that {motion} moves over
+p               paste after cursor
+P               paste before cursor
+d               delete a character
+xd              delete a line
+v{motion}d      delete text that {motion} moves over
\ No newline at end of file
diff --git a/ifconfig b/ifconfig
index ed6c15f9..aa9e32bc 100644
--- a/ifconfig
+++ b/ifconfig
@@ -5,7 +5,7 @@ ifconfig <interface>
 ifconfig -a
 
 # To take down / up the wireless adapter:
-ifconfig wlan0 {up|down} 
+ifconfig wlan0 {up|down}
 
 # To set a static IP and netmask:
 ifconfig eth0 192.168.1.100 netmask 255.255.255.0
diff --git a/iptables b/iptables
index 2da02d8a..182afa8d 100644
--- a/iptables
+++ b/iptables
@@ -23,6 +23,8 @@ iptables -A INPUT -i eth0 -p tcp --dport 902 -j REJECT --reject-with icmp-port-u
 # To add a comment to a rule:
 iptables ... -m comment --comment "This rule is here for this reason"
 
+# To only allow ssh on the server and block all other ports:
+iptables --append <INPUT> --protocol tcp --dport 22 --jump <ACCEPT> 
 
 # To remove or insert a rule:
 # 1) Show all rules
diff --git a/java b/java
index 403bd753..d87dfc79 100644
--- a/java
+++ b/java
@@ -25,7 +25,7 @@ OpenJDK 64-Bit Server VM (build 11.0.8+10-post-Ubuntu-0ubuntu120.04, mixed mode,
 java -Xms256m -Xmx2g -Xss1m -jar <filename.jar>
 
 # To use the classpath variable
-# It overrides the CLASSPATH of Environment variable but only for that session. 
+# It overrides the CLASSPATH of Environment variable but only for that session.
 # If you restart the application you need to again set the classpath variable.
 # You can use either: -classpath, --classpath or -cp
 java -classpath <classpath> -jar <filename.jar>
diff --git a/kitty b/kitty
index d56906f3..99037c45 100644
--- a/kitty
+++ b/kitty
@@ -25,12 +25,12 @@ ctrl+shift+,         - Move tab backward
 ctrl+shift+alt+t     - Set tab title
 
 # Fonts and clipboard
-ctrl+shift+c         - Copy to clipboard	    
+ctrl+shift+c         - Copy to clipboard	
 ctrl+shift+v         - Paste from clipboard	
 ctrl+shift+s         - Paste from selection	
 ctrl+shift+equal     - Increase font size	
 ctrl+shift+minus     - Decrease font size	
-ctrl+shift+backspace - Restore font size	    
+ctrl+shift+backspace - Restore font size	
 
 # Windows
 ctrl+shift+enter     - New window
@@ -44,7 +44,7 @@ ctrl+shift+`         - Move window to top
 ctrl+shift+f7        - Visually focus window
 ctrl+shift+f8        - Visually swap window
 # Focus specific window
-ctrl+shift+1, ctrl+shift+2 … ctrl+shift+0 
+ctrl+shift+1, ctrl+shift+2 … ctrl+shift+0
 
 # Open/select
 ctrl+shift+e         - Open URL
diff --git a/losetup b/losetup
new file mode 100644
index 00000000..d6a42766
--- /dev/null
+++ b/losetup
@@ -0,0 +1,12 @@
+---
+tags: [ mount loop ]
+---
+
+# Output available loop device
+$ losetup -f
+
+# Attach an image file with partitioning table on available loop device
+$ losetup "$(losetup -f)" path/to/file.img
+
+# Detatch loop device
+$ losetup -d /dev/loopX
\ No newline at end of file
diff --git a/ls b/ls
index a19fe448..3a703833 100644
--- a/ls
+++ b/ls
@@ -17,7 +17,7 @@ ls -d */ <dir>
 ls -d .*/ */ <dir>
 
 # To display all files sorted by changed date, most recent first:
-ls -ltc 
+ls -ltc
 
 # To display files sorted by create time:
 ls -lt
@@ -31,3 +31,6 @@ ls -1
 
 # To show all the subtree files (Recursive Mode):
 ls -R
+
+# To ....
+ls -lhta
\ No newline at end of file
diff --git a/markdown b/markdown
index 53b0d1c3..44b17472 100644
--- a/markdown
+++ b/markdown
@@ -37,7 +37,7 @@ Sub-bullets can be done with 2+ spaces or 1 tab
   a. Lettered  <-- there is mixed support for this format
 4. Fourth
   i. using roman numerals  <-- there is mixed support for this format
-  ii. more stuff 
+  ii. more stuff
 
 ## check list
 There is limited support for rendering check lists:
@@ -86,7 +86,7 @@ Assuming you have a heading called `# My First Heading` then link is the case-in
 Italic:
 *em* _em_
 
-Bold: 
+Bold:
 **strong** __strong__
 
 ~~strikethrough~~
@@ -98,8 +98,8 @@ The alignment applies to the table data, not the header.
 
 Left-aligned Stuff | Right-aligned Stuff | Center-aligned Stuff
 | :--- | ---: | :---:
-Some left stuff   | Some right stuff  | Some center stuff 
-Some left stuff   | Some right stuff  | Some center stuff 
+Some left stuff   | Some right stuff  | Some center stuff
+Some left stuff   | Some right stuff  | Some center stuff
 
 ## Special Characters in Tables
 First Header  | Second Header
diff --git a/multipass b/multipass
index 52f48733..9cd4b22e 100644
--- a/multipass
+++ b/multipass
@@ -1,5 +1,5 @@
 # List all options
-multipass 
+multipass
 
 # List existing VMs on your device
 multiplass list
diff --git a/mutt b/mutt
index 0c459459..3d5b7d23 100644
--- a/mutt
+++ b/mutt
@@ -1,6 +1,6 @@
 # Create new mailbox in IMAP
 	+ When located in mailbox list (c)
-		shift + C 
+		shift + C
 
 # Move multiple messages to folder (bulk operations)
 	
@@ -17,4 +17,4 @@
 		~A
 
 	3. It should mark all for deletion!
-	4. Conversely, you can do the same thing with UPPERCASE U to undelete multiple messages. 
+	4. Conversely, you can do the same thing with UPPERCASE U to undelete multiple messages.
diff --git a/mv b/mv
index 2ff826fe..278fee15 100644
--- a/mv
+++ b/mv
@@ -14,4 +14,4 @@ mv -i <src> <dest>
 mv -n <src> <dest>
 
 # To move listed file(s) to a directory
-mv -t <dest> <file>...
+mv -t <dest> <file1> <file2>
diff --git a/openssl b/openssl
index 2a1470f3..983d2b02 100644
--- a/openssl
+++ b/openssl
@@ -13,7 +13,7 @@ openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
 openssl req -text -noout -in server.csr
 
 # To show certificate information for generated certificate
-openssl x509 -text -noout -in server.crt 
+openssl x509 -text -noout -in server.crt
 
 # To get the sha256 fingerprint of a certificate
 openssl x509 -in server.crt -noout -sha256 -fingerprint
@@ -30,12 +30,12 @@ openssl dhparam -outform PEM -out dhparams.pem 2048
 openssl s_client -connect 10.240.2.130:433
 
 # High-quality options for openssl for symmetric (secret key) encryption
-  
-This is what knowledgable people consider a good set of options for 
+
+This is what knowledgable people consider a good set of options for
 symmetric encryption with openssl to give you a high-quality result.
 Also, always remember that the result is only as good as the password
 you use. You must use a strong password otherwise encryption is meaningless.
-  
+
 openssl enc -e -aes-256-cbc \
   -salt \
   -pbkdf2 \
diff --git a/p4 b/p4
index d956f8ce..e6b55c71 100644
--- a/p4
+++ b/p4
@@ -1,7 +1,7 @@
 tags: [ vcs ]
 
 # To print details related to client and server configuration:
-p4 info 
+p4 info
 
 # To open a file and add it to depot:
 p4 add <filename>
diff --git a/pandoc b/pandoc
index 64356c53..de076386 100644
--- a/pandoc
+++ b/pandoc
@@ -1,5 +1,10 @@
-# Convert HTML file to Markdown
-pandoc -f html -t markdown  -i <HTML input file> -o  <markdown output file>
+---
+syntax: bash
+tags: [converters, markdown]
+---
 
-# Convert Markdown file to HTML
-pandoc -f markdown -t html -i <markdown input file>  -o <HTML output file>
+# Convert HTML file to Markdown:
+pandoc --from=html --to=markdown --output=<path/to/markdown_output_file> <path/to/html_input_file>
+
+# Convert Markdown file to HTML:
+pandoc --from=markdown --to=html --output=<path/to/html_output_file> <path/to/markdown_input_file>
\ No newline at end of file
diff --git a/pdfgrep b/pdfgrep
new file mode 100644
index 00000000..5ddf5cb4
--- /dev/null
+++ b/pdfgrep
@@ -0,0 +1,11 @@
+# search word in pdf file:
+pdfgrep "keyword" file-name.pdf
+
+# search work in multiple pdf files on multiple folders:
+pdfgrep -R "keyword" storage-folder/*
+
+# show page number & filename
+pdfgrep -RHn "keyword" storage-folder/*
+
+# search words with regular expression
+pdfgrep -RHnp "key...." storage-folder/*
\ No newline at end of file
diff --git a/port b/port
index 79fdac66..75ecab8f 100644
--- a/port
+++ b/port
@@ -71,14 +71,14 @@ port rdependents <name>
 # (Only works for currently installed ports.)
 port contents <name>
 
-# View a ports' notes, if any (these are usually displayed right after a port 
+# View a ports' notes, if any (these are usually displayed right after a port
 # is installed):
 port notes <name>
 
 # Print the path to a port within the ports tree:
 port dir <name>
 
-# Print the path to the archive used to activate a given port: 
+# Print the path to the archive used to activate a given port:
 # (Only works for currently installed ports)
 port location <name>
 
diff --git a/prqlc b/prqlc
new file mode 100644
index 00000000..3d701aa2
--- /dev/null
+++ b/prqlc
@@ -0,0 +1,16 @@
+# PRQL is a modern language for transforming data — a simple, powerful, pipelined SQL replacement.
+
+# Run the compiler interactively:
+prqlc compile
+
+# Compile a .prql file standard output:
+prqlc compile <file.prql>
+
+# Compile a .prql file to a .sql file:
+prqlc compile <in-file.prql> <out-file.sql>
+
+# Compile a query:
+echo "from employees | filter has_dog | select salary" | prqlc compile
+
+# Watch a directory and compile on file modification:
+prqlc watch <dir>
\ No newline at end of file
diff --git a/pstree b/pstree
new file mode 100644
index 00000000..173b906d
--- /dev/null
+++ b/pstree
@@ -0,0 +1,14 @@
+# To show one tree, starting at pid 1:
+pstree
+
+# To show descendents of <pid>:
+pstree <pid>
+
+# To show parents and descendents of <pid>:
+pstree -u <pid>
+
+# To use utf-8 'graphics' for trees when calling with [args]:
+pstree -g 2 <args>..
+
+# To show tree for processes owned by <user>:
+pstree -u <user>
\ No newline at end of file
diff --git a/r2 b/r2
index 402a9168..1eb5761f 100644
--- a/r2
+++ b/r2
@@ -53,22 +53,22 @@
 # Basic Commands
 
 	; Command chaining: x 3;s+3;pi 3;s+3;pxo 4;
-    
+
 	| Pipe with shell commands: pd | less
-    
+
 	! Run shell commands: !cat /etc/passwd
-    
+
 	!! Escapes to shell, run command and pass output to radare buffer
     		
 		Note: 	The double exclamation mark tells radare to skip the plugin list to find an IO plugin handling this
 			command to launch it directly to the shell. A single one will walk through the io plugin list.
 
     	` Radare commands: wx `!ragg2 -i exec`
-    
+
 	~ grep
-    
+
 	~! grep -v
-    
+
 	~[n] grep by columns afl~[0]
 
     	~:n grep by rows afl~:0
@@ -96,13 +96,13 @@
 	.. repeats last commands (same as enter \n)
     	
 	( Used to define and run macros
-    
+
 	$ Used to define alias
-    
+
 	$$: Resolves to current address
     	
 	Offsets (@) are absolute, we can use $$ for relative ones @ $$+4
-    
+
 	? Evaluate expression
 	+-------------------------------------------------------------------
 
@@ -113,33 +113,33 @@
 	+-------------------------------------------------------------------
 
 	?$? Help for variables used in expressions
-    
+
 	$$: Here
-    
+
 	$s: File size
-    
+
 	$b: Block size
-    
+
 	$l: Opcode length
-    
+
 	$j: When $$ is at a jmp, $j is the address where we are going to jump to
-    
+
 	$f: Same for jmp fail address
 	
 	$m: Opcode memory reference (e.g. mov eax,[0x10] => 0x10)
-    
+
 	??? Help for ? command
-    
+
 	?i Takes input from stdin. Eg ?i username
-    
+
 	?? Result from previous operations
-    
+
 	?s from to [step]: Generates sequence from to every
-    
+
 	?p: Get physical address for given virtual address
-    
+
 	?P: Get virtual address for given physical one
-    
+
 	?v Show hex value of math expr
 
 	+-------------------------------------------------------------------
@@ -150,7 +150,7 @@
 	+-------------------------------------------------------------------
 
 	?l str: Returns the length of string
-    
+
 	@@: Used for iteractions
 
 	+-------------------------------------------------------------------
@@ -307,7 +307,7 @@
     		wow 11223344 @102!10
         		write looped value from 102 to 102+10
         		0x00000066  1122 3344 1122 3344 1122 0000 0000 0000
-    
+
 	wox 0x90
         	XOR the current block with 0x90. Equivalent to wox 0x90 $$!$b (write from current position, a whole block)
     	
@@ -646,7 +646,7 @@
 
 	-S: binary to hex (for files)
 	
-	-N: pack an integer 
+	-N: pack an integer
 		rax2 -N 0x1234 # \x34\x12\x00\x00
 
 # rahash2 - Entropy, hashes and checksums
@@ -681,7 +681,7 @@
 	+-------------------------------------------------------------------
 
 # rasm2 - Assembly/Disasembly
- 
+
 	-L: Supported architectures
 
 	-a arch instruction: Sets architecture
@@ -844,7 +844,7 @@
 		https://github.com/jpenalbae/r2-scripts
 # Parsing ELF
 	
-	!!! open with r2 -nn 
+	!!! open with r2 -nn
 
 	+ Parse 9 program headers (elf_phdr) from curr. seek plus offset 0x40 with temporary block size 0x200 in less mode (~..)
 
diff --git a/range b/range
new file mode 100644
index 00000000..b3ea9878
--- /dev/null
+++ b/range
@@ -0,0 +1,95 @@
+---
+syntax: bash
+tags: [file manager]
+---
+
+# Ranger Cheatsheet
+
+# A VIM-inspired filemanager for the console
+
+# https://github.com/ranger/ranger
+
+# General
+
+ranger start Ranger
+
+Q quit Ranger
+R reload current directory
+? Ranger Manpages / Shortcuts
+: execute Range Command
+! execute Shell Command
+S run the terminal in your current ranger window (exit to go back to ranger)
+
+# Movement
+
+k up
+j down
+h parent directory
+l subdirectory
+gg go to top of list
+G go t bottom of list
+J half page down
+K half page up
+H history Back
+L history Forward
+~ switch the view
+
+# File Operations
+
+<Enter> open file
+r open file with
+i read file
+z open settings
+zh set show_hidden_files
+zp set preview_files
+zz console filter :filter
+zd set sort_directories_first
+o change sort order
+<backspace> toggle show_hidden_files
+cw rename file
+a rename-append
+I rename-overwrite
+yy yank / copy
+dd cut
+pp paste
+/ search for files :search
+n next match
+N prev match
+.f filter stack on type 'file'
+.d filter stack on type 'directory'
+.l filter stack on type 'link'
+.c clear filter
+<space> mark files
+v mark files all=True toggle=True
+dD delete
+<delete> delete
+Mp show file permissions
+chmod nnn change file permissions
+nnn= change file permissions
+dc show cummulative size
+
+# Tabs
+
+gn tab_new
+gc tab_close
+gt tab_move 1
+gT tab_move -1
+
+# File substituting
+
+%f substitute highlighted file
+%d substitute current directory
+%s substitute currently selected files
+%t substitute currently tagged files
+
+# Example for substitution
+
+:bulkrename %s
+
+# Marker
+
+m+<letter> create Marker
+um+<letter> delete Marker
+'+<letter> go to Marker
+t tag a file with an \*
+t"<any> tag a file with your desired mark
diff --git a/rmdir b/rmdir
index a5dae1ed..8c63299b 100644
--- a/rmdir
+++ b/rmdir
@@ -1,5 +1,5 @@
 # Command syntax:
-rmdir [option] directory_name 
+rmdir [option] directory_name
 
 # Outputs a message that the directory is being removed:
 rmdir -v directory_name
diff --git a/sar b/sar
index 3d798931..226caadc 100644
--- a/sar
+++ b/sar
@@ -8,7 +8,7 @@ sar -u 2 5
 # Report the CPU usage for a given core:
 sar -P 1 1 3
 
-# Reports the amount of memory used, amount of memory free, available cache, available buffers every 1 second, 3 times: 
+# Reports the amount of memory used, amount of memory free, available cache, available buffers every 1 second, 3 times:
 sar -r 1 3
 
 # Reports statistics on swapping:
diff --git a/sha256sum b/sha256sum
index 11e40d43..42d30b7a 100644
--- a/sha256sum
+++ b/sha256sum
@@ -15,15 +15,15 @@ echo -n "Hello World" | sha256sum
 # To verify if a hash (checksum) is correct if a hash-file is provided:
 # sha256sum will go thru the files listed in <file-with-list-of-checksums>.
 # For each file it will look if it exists. If not, it will print an error.
-# If it does exist it will compute the checksum and compare it with the hash 
+# If it does exist it will compute the checksum and compare it with the hash
 # provided in the <file-with-list-of-checksums>. If they match (good!) it
-# will print "filename: OK". 
-# If they don't match (warning, you might have been hacked), it will 
+# will print "filename: OK".
+# If they don't match (warning, you might have been hacked), it will
 # print "filename: FAILED".
 sha256sum --check <file-with-list-of-checksums>
 
 # Same as above (but ignore missing files):
-# This tells you if your file is an exact copy (OK) or has been 
+# This tells you if your file is an exact copy (OK) or has been
 # tampered with (FAILED) without bothering you with warnings about
 # missing files
 sha256sum --check --ignore-missing <file-with-list-of-checksums>
diff --git a/socat b/socat
index 2d28600e..62fbbd18 100644
--- a/socat
+++ b/socat
@@ -12,9 +12,9 @@ socat -x tcp-listen:3180,fork -
 
 # practical examples:
 
-# complete real working http-example:  
+# complete real working http-example:
 #  (sleep is necessary to prevent socat closing socket before data received)
-(echo -e "GET / HTTP/1.1\r\nHost: butzel.info\r\n\r" && sleep 1) \ 
+(echo -e "GET / HTTP/1.1\r\nHost: butzel.info\r\n\r" && sleep 1) \
 | socat tcp4:butzel.info:80 -
 
 # http to httpS 'Proxy' (for an webserver without TLS-Support)
diff --git a/ss b/ss
index f4da8cc7..1bf57880 100644
--- a/ss
+++ b/ss
@@ -11,6 +11,9 @@ Args
 # show all listening tcp sockets including the corresponding process
 ss -tlp
 
+# show all listening tcp sockets including the corresponding process, netid
+ss -tulp
+
 # show all sockets connecting to 192.168.2.1 on port 80
 ss -t dst 192.168.2.1:80
 
diff --git a/su b/su
index 286941ce..49dafe91 100644
--- a/su
+++ b/su
@@ -1,2 +1,5 @@
 # To switch to another user account:
 su <user>
+
+# To switch to another user - inherit that user's bash configuration
+su - <user>
\ No newline at end of file
diff --git a/systemctl b/systemctl
index ae0b8b74..9313c459 100644
--- a/systemctl
+++ b/systemctl
@@ -55,7 +55,7 @@ journalctl -b -u foo.service
 # To list the dependencies of a service:
 # when no service name is specified, lists the dependencies of default.target
 # add -all to expand dependencies recursively
-systemctl list-dependencies foo.service 
+systemctl list-dependencies foo.service
 
 # To see low level details of a service settings on the system:
 systemctl show foo.service
diff --git a/terraform b/terraform
index 15863a0a..6d6b69f9 100644
--- a/terraform
+++ b/terraform
@@ -21,10 +21,10 @@ terraform apply
 
 terraform destroy
 
-# To upgrade your [Terraform providers](https://www.terraform.io/docs/providers/index.html), which are distributed separately from the Terraform binary. 
+# To upgrade your [Terraform providers](https://www.terraform.io/docs/providers/index.html), which are distributed separately from the Terraform binary.
 
 terraform init -upgrade
 
-# To upgrade your [Terraform modules](https://www.terraform.io/docs/modules/index.html), which are distributed separately from the Terraform binary. 
+# To upgrade your [Terraform modules](https://www.terraform.io/docs/modules/index.html), which are distributed separately from the Terraform binary.
 
 terraform get -update
diff --git a/tmux b/tmux
index 80a90a33..b8cf9649 100644
--- a/tmux
+++ b/tmux
@@ -8,7 +8,7 @@ Ctrl-b d
 tmux attach
 
 # To detach an already attached session (great if you are moving devices with different screen resolutions):
-tmux attach -d 
+tmux attach -d
 
 # To display session:
 tmux ls
@@ -53,3 +53,9 @@ Ctrl-b "
 
 # To swap windows:
 Ctrl-b :swap-window -s [0-9] -t [0-9]
+
+# To copy/paste
+1. Enter 'copy mode' by pressing CTRL+b, [.
+2. Use the arrow keys to go to the position from where you want to start copying. Press CTRL+SPACE to start copying.
+3. Use arrow keys to go to the end of text you want to copy. Press ALT+w or CTRL+w to copy into Tmux buffer.
+4. Press CTRL+b, ] to paste in a possibly different Tmux pane/window.
\ No newline at end of file
diff --git a/top b/top
index 022fa66e..6a8b9a76 100644
--- a/top
+++ b/top
@@ -4,23 +4,20 @@ top -i <interval>
 # To set the delay between updates to <delay> seconds:
 top -s <delay>
 
-# To set event counting to accumulative mode:
-top -a
+# To set memory unit <KB, MB, GB, TB, PB, EB>
+top -E <k,m,g,t,p,e>
 
-# To set event counting to delta mode:
-top -d
-
-# To set event counting to absolute mode:
-top -e
-
-# To not calculate statistics on shared libraries, also known as frameworks:
-top -F
-
-# To calculate statistics on shared libraries, also known as frameworks (default):
-top -f
+# To monitor specific process IDs (maximum is 20 process IDs)
+top -pN1,N2,N3,...N20
 
 # To print command line usage information and exit:
 top -h
 
 # To order the display by sorting on <key> in descending order:
 top -o <key>
+
+# Basic command use after enter `top`
+- f: show/hide fields, sort fiend
+  - d: show/hide field
+  - s: select as sort field
+  - a/w: keep this custom field forever
\ No newline at end of file
diff --git a/tr b/tr
index 13a9b80c..825c0ec1 100644
--- a/tr
+++ b/tr
@@ -1,22 +1,22 @@
 # To replace : with a new line:
 echo $PATH | tr ":" "\n"
-echo $PATH | tr -t ":" \n 
+echo $PATH | tr -t ":" \n
 
 # To remove all occurance of "ab":
-echo aabbcc | tr -d "ab"         # ouput: cc
+echo aabbcc | tr -d "ab" # ouput: cc
 
 # To complement "aa":
 # ("Complement" means to keep "aa", and replace all others with "x")
-echo aabbccd | tr -c "aa" x       # output: aaxxxxx (no newline)
+echo aabbccd | tr -c "aa" x # output: aaxxxxx (no newline)
 
 # To complement "ab\n":
-echo aabbccd | tr -c "ab\n" x    #output: aabbxxx (with newline)
+echo aabbccd | tr -c "ab\n" x #output: aabbxxx (with newline)
 
 # To preserve all alpha(-c). ":-[:digit:] etc" will be translated to "\n". sequeeze mode:
-echo $PATH | tr -cs "[:alpha:]" "\n" 
+echo $PATH | tr -cs "[:alpha:]" "\n"
 
 # To convert an ordered list to an unordered list:
 echo "1. /usr/bin\n2. /bin" | tr -cs " /[:alpha:]\n" "+"
 
 # To remove all NULLs:
-tr < file-with-nulls -d '\000' > file-without-nulls
+tr <file-with-nulls -d '\000' >file-without-nulls
diff --git a/udisksctl b/udisksctl
index c4d5233f..176a2f18 100644
--- a/udisksctl
+++ b/udisksctl
@@ -8,4 +8,4 @@ udisksctl mount --block-device <device>
 udisksctl unmount --block-device <device>
 
 # To get help:
-udisksctl help 
+udisksctl help
diff --git a/ufw b/ufw
new file mode 100644
index 00000000..2baa153b
--- /dev/null
+++ b/ufw
@@ -0,0 +1,28 @@
+# To check the status of the firewall:
+ufw status
+
+# To check the status with more details:
+ufw status verbose
+
+# To allow a port on the firewall by its name:
+ufw allow <PORT-NAME>
+ufw allow http
+ufw allow https
+ufw allow ssh
+ufw allow ftp
+
+# To allow a port on the firewall by its number:
+ufw allow <port-number>
+ufw allow 5432
+
+# To delete an allowed port rule on the firewall:
+ufw delete allow 5432
+
+# To block a port on the firewall:
+ufw deny 21
+
+# To enable the firewall and activate the rules:
+ufw enable
+
+# To disable the firewall and deactivate the rules:
+ufw disable
\ No newline at end of file
diff --git a/vim-plugins/vim-surround b/vim-plugins/vim-surround
new file mode 100644
index 00000000..3b4186e5
--- /dev/null
+++ b/vim-plugins/vim-surround
@@ -0,0 +1,44 @@
+---
+tags: [ vim,vim-plugins ]
+---
+
+# https://github.com/tpope/vim-surround
+
+# To surround with the specified character:
+`ys{motion}{character}`
+ex: ysiw)		foo => (foo)
+	ysiw(		foo => ( foo )
+	ysiw]		foo => [foo]
+	ysiw[		foo => [ foo ]
+	ysiw<p>		foo => <p>foo</p>
+	yss}		foo => {foo}	# surround the whole line with {} (ignores leading whitespace)
+	ySS}		foo => {
+							foo # indent the line and place it on a new line
+					   }
+
+# To change the current surrounding character:
+`cs{old}{new}`
+ex: cs([		(foo) => [foo]
+	cs[(		[foo] => (foo)
+	cs"<q>		"foo" => <q>foo</q>
+
+# To delete the current surrounding:
+`ds{character}` # delete the surrounding character
+`dst` # delete the surrounding HTML tag
+ex: ds(		(foo) => foo
+	ds[		[foo] => foo
+	dst		<p>foo</p> => foo
+
+# To surround with function:
+`ysWf{function_name}<CR>`
+ex: ysWfprint<CR>	"foo" => print("foo")
+	ysWFprint<CR>	"foo" => print( "foo" )
+
+# Legend
+
+ys = "you surround"
+b = ()
+B = {}
+r = []
+a = <>
+t = HTML tag
\ No newline at end of file
diff --git a/watch b/watch
new file mode 100644
index 00000000..e9317087
--- /dev/null
+++ b/watch
@@ -0,0 +1,2 @@
+# To watch a command and update the output every 2 seconds:
+watch <command>
\ No newline at end of file
diff --git a/xargs b/xargs
index b4a3ace6..10eaa42b 100644
--- a/xargs
+++ b/xargs
@@ -1,8 +1,16 @@
-# To Find all file name ending with .pdf and remove them
-find -name *.pdf | xargs rm -rf
+---
+syntax: bash
+---
 
-# if file name contains spaces you should use this instead
-find -name *.pdf | xargs -I{} rm -rf '{}'
+# Find all files whose names end with .pdf and remove them:
+find -type f -name '*.pdf' | xargs rm -f
+
+# If file names contain special characters, you should use this instead.
+# Special characters include spaces, quotes, parenthesis, unicode, etc:
+find -type f -name '*.pdf' -print0  | xargs --null rm -f
+
+# Run 4 `rm` commands in parallel
+find -name '*.pdf' | xargs --max-procs=4 rm -f
 
 # Will show every .pdf like:
 #	&toto.pdf=
diff --git a/yaourt b/yaourt
index 4d742f24..77037216 100644
--- a/yaourt
+++ b/yaourt
@@ -3,7 +3,7 @@ tags: [ packaging ]
 ---
 # All pacman commands are working the same way with yaourt.
 # Just check the pacman cheatsheet.
-# For instance, to install a package: 
+# For instance, to install a package:
 pacman -S <package>
 yaourt -S <package>
 # The difference is that yaourt will also query the Arch User Repository,
@@ -19,7 +19,7 @@ yaourt <package>
 # svn, hg...)
 yaourt -Suya --devel
 
-# For all of the above commands, if you want yaourt to stop asking constantly for confirmations, 
+# For all of the above commands, if you want yaourt to stop asking constantly for confirmations,
 use the option --noconfirm
 
 # To build <package> from source:
diff --git a/yum b/yum
index b86ed33e..c0153491 100644
--- a/yum
+++ b/yum
@@ -27,7 +27,7 @@ yum repolist
 
 # List packages matching <phrase>:
 yum list <phrase>
- 
+
 # To download the source RPM for a package:
 yumdownloader --source <package>