Merge branch 'master' of https://github.com/chubin/cheat.sheets

sheets/_bash/shortcuts

@@ -34,6 +34,7 @@ Ctrl + p   - previous command (↑)
 Ctrl + n   - next command (↓)
 Ctrl + o   - execute displayed command from history, don't clear command line
  Alt + .   - recall last argument (word) of last executed command
+ Alt + - + . - recall second last argument (word) of last executed command
 
 # -= Terminal control =-
 Ctrl + l   - clear screen, don't clear command line

sheets/_js/weirdness

@@ -4,6 +4,9 @@
 // Null is an Object
 typeof null // => 'object'
 
+// Weird decimal calculation
+0.1 + 0.2 // -> 0.30000000000000004
+
 // Despite this, null is not an instance of an Object
 null instanceof Object // => false
 

sheets/_python3/decorator

@@ -0,0 +1,41 @@
+# A decorator is a design pattern in Python that allows a user
+# to add new functionality to an existing object without modifying
+# its structure. Decorators are usually called before the definition
+# of a function you want to decorate.
+# In simple words: they are functions which modify the functionality
+# of other functions.
+
+from datetime import datetime
+
+def my_decorator(func):
+    def wrapper():
+        print('start', datetime.now())
+        func()
+        print('end', datetime.now())
+    return wrapper
+
+@my_decorator
+def my_method():
+    for i in range(1, 100000):
+        pass
+
+my_method()
+# start 2021-06-07 15:29:51.330086
+# end 2021-06-07 15:29:51.333832
+
+# Decorator with function parameters.
+def my_decorator(func):
+    def wrapper(start, end):
+        print('start', datetime.now())
+        func(start, end)
+        print('end', datetime.now())
+    return wrapper
+
+@my_decorator
+def my_method(start, end):
+    for i in range(start, end):
+        pass
+
+my_method()
+# start 2021-06-07 15:29:51.330086
+# end 2021-06-07 15:29:51.333832

sheets/_python3/generator

@@ -0,0 +1,20 @@
+# Declare a function that behaves like an iterator.
+# Any function with yield returns generator.
+# Generators follow lazy evaluation.
+# lazy evaluation means that the object is evaluated when it is needed,
+# not when it is created.
+
+def my_generator(start, end, step=1):
+    while start < end:
+        yield start
+        start += step
+
+gen = my_generator(start=1, end=10)
+next(gen), next(gen), next(gen)
+# (1, 2, 3)
+
+gen = (i for i in range(1, 100) if i%2==0)
+next(gen), next(gen), next(gen), next(gen)
+# (2, 4, 6, 8)
+
+# https://wiki.python.org/moin/Generators

sheets/_scala/ManipulatingCollections

@@ -20,7 +20,7 @@ l map {    //note: the curly brackets allow us to make the map multi-line and us
 l filter (_ % 2 == 0)   //returns List(2,4)
 
 // filterNot
-l filter (_ % 2 == 0)   //returns List(1,3,5)
+l filterNot (_ % 2 == 0)   //returns List(1,3,5)
 
 // collect
 // this is like a combination of filter and map

sheets/_scala/ObjectOrientation

@@ -35,7 +35,7 @@ abstract class D { ... }
 class C extends D { ... }
 class D(var x: R)
 
-// inheritance and constructor params. (wishlist: automatically pass-up params
+// inheritance and constructor params. (wish list: automatically pass-up params
 // by default)
 class C(x: R) extends D(x)
 

sheets/_theory/recursion

@@ -2,7 +2,7 @@
 # Method for when the solution to a problem depends on solutions to smaller
 # instance of the same problem; a self-calling function.
 
-# Recursive programs - Pseduocode
+# Recursive programs - Pseudocode
 function factorial:
 input: integer n such that n >= 0
 output: n * (n-1) * (n-2) * ... * 1 = n!

sheets/apt-config

@@ -0,0 +1,10 @@
+# apt-config
+# APT Configuration Query program
+
+# List all APT (and related) configuration options and their values.
+apt-config dump
+
+# List regular expressions used to match packages to be ignored by apt-get(8)'s
+# `autoremove` functionality. Assumes `;` or some other undesired character
+# will be at the end of the string.
+apt-config dump | awk '/^APT::NeverAutoRemove::/ {print(substr($2, 0, length($2) - 1))}'

sheets/awk

@@ -48,7 +48,7 @@ awk '{NR != 1 && A[$1]=$2} END {print(A["Mem:"])}' <(free -h)
 # the same, and in other cases, the above is definitely preferable.
 awk '/^Mem:/ {print($2)}' <(free -h)
 
-# Output list of unique uppercase-only, sigil-omitted variables used in [FILE].
+# Output list of unique uppercase-only, sigil-omitted variables used in FILE.
 awk '
     {
         for(F=0; F<NF; F++){
@@ -63,10 +63,10 @@ awk '
             printf("%s\n", X)
         }
     }
-' [FILE]
+' FILE
 
 # Output only lines from FILE between PATTERN_1 and PATTERN_2. Good for logs.
-awk '/PATTERN_1/,/PATTERN_2/ {print}' [FILE]
+awk '/PATTERN_1/,/PATTERN_2/ {print}' FILE
 
 # Pretty-print a table of an overview of the non-system users on the system.
 awk -F ':' '
@@ -82,3 +82,21 @@ awk -F ':' '
 # a painful but useful workaround to get the units comma-separated, as would be
 # doable with Bash's own `printf` built-in.
 awk '/^MemTotal:/ {printf("%'"'"'dMiB\n", $2 / 1024)}'
+
+# It's possible to sort strings in AWK, as well as uniq-ing, meaning you can
+# replace uniq(1) and sort(1) calls with just the one call of AWK. Granted, you
+# can use `sort -u` to do both, but AWK offers much more functionality.
+#
+# Unlike when using AWK to uniq-ify, uniq(1) only works by adjacency, meaning
+# the duplicate lines must be adjacent to one another for them to be handled.
+awk '
+	{
+		!Lines[$0]++
+	}
+	END {
+		asorti(Lines, Sorted)
+		for (Line in Sorted) {
+			print(Sorted[Line])
+		}
+	}
+' FILE

sheets/az

@@ -45,7 +45,7 @@ az vm open-port --resource-group MyRG --name MyLinuxVM --port 443 --priority 899
 # Show storage accounts
 az storage account list --output table
 
-# Show contaniers for an account
+# Show containers for an account
 az storage container list --account-name mystorageaccount --output table
 
 # Show blobs in a container

sheets/btrfs

@@ -8,13 +8,13 @@ mkfs.btrfs -m single /dev/sdb
 # data to be redundant and metadata to be non-redundant:
 mkfs.btrfs -m raid0 -d raid1 /dev/sdb /dev/sdc /dev/sdd
 
-# both data and metadata to be redundan
+# both data and metadata to be redundant
 mkfs.btrfs -d raid1 /dev/sdb /dev/sdc /dev/sdd
 
 # To get a list of all btrfs file systems
 btrfs filesystem show
 
-# detailed df for a fileesystem (mounted in /mnt)
+# detailed df for a filesystem (mounted in /mnt)
 btrfs filesystem df /mnt
 
 # resize btrfs online (-2g decreases, +2g increases)

sheets/cat

@@ -1,4 +1,4 @@
-# POSIX-ly correct way in which to cat(1); see cat(1posix).
+# POSIX way in which to cat(1); see cat(1posix).
 cat -u [FILE_1 [FILE_2] ...]
 
 # Output a file, expanding any escape sequences (default). Using this short

sheets/currency

@@ -1,5 +1,5 @@
 # Currency (Bash-Snippets)
-# A realtime currency converter
+# A real time currency converter
 
 # To convert between currencies (guided)
 currency

sheets/dcfldd

@@ -1,5 +1,5 @@
 # enhanced version of GNU dd with features useful for forensics and security.
-# includes ability to have mulitple output targets
+# includes ability to have multiple output targets
 
 # write file image to an SD card showing a progress bar based on filesize
 sudo dcfldd if=./raspbian.img of=/dev/mmcblk0 sizeprobe=if

sheets/dict

@@ -1,11 +1,19 @@
 # dict
-# Dictionary client
+# dictd - Client/server software, human language dictionary databases, and tools supporting the DICT protocol
 
-# A list of all the available dictionaries can be queried by executing.
+# List available dictionary databases
+dict -D
+
+# Get information about a dictionary database (e.g. moby-thesaurus)
+dict -i moby-thesaurus
+
+# Look up "use" in Moby-Thesaurus database
+dict -d moby-thesaurus use
+
+# Look up "perceive" in all available dictionary databases
+dict perceive
+
+# List all the available dictionaries server and their info
 dict -I
 
-# Translate 'understand' to Dutch.
-dict -d fd-eng-nld understand
 
-# Show available dict databases.
-dict -D

sheets/emacs

@@ -7,8 +7,8 @@
     C-x b       create/switch buffers
     C-x C-b     show buffer list
     C-x k       kill buffer
-    C-z         suspend emacs
-    C-X C-c     close down emacs
+    C-z         suspend Emacs
+    C-X C-c     close down Emacs
 
 # Basic movement
     C-f         forward char
@@ -65,11 +65,11 @@
     C-h f       what does this function do
     C-h v       what\'s this variable and what is it\'s value
     C-h b       show all keycommands for this buffer
-    C-h t       start the emacs tutorial
+    C-h t       start the Emacs tutorial
     C-h i       start the info reader
     C-h C-k     start up info reader and go to a certain key-combo point
-    C-h F       show the emacs FAQ
-    C-h p       show infos about the Elisp package on this machine
+    C-h F       show the Emacs FAQ
+    C-h p       show info about the Elisp package on this machine
 
 # Search/Replace
     C-s         Search forward
@@ -122,7 +122,7 @@
     C-x 5 0     close this frame
 
 # Bookmark commands
-    C-x r m     set a bookmark at current cursor pos
+    C-x r m     set a bookmark at current cursor position
     C-x r b     jump to bookmark
     M-x bookmark-rename
     M-x bookmark-delete
@@ -147,10 +147,10 @@
 
 # Shell
     M-x         shell starts shell modus
-    C-c C-c     same as C-c under unix (stop running job)
+    C-c C-c     same as C-c under Unix (stop running job)
     C-d         delete char forward
     C-c C-d     Send EOF
-    C-c C-z     suspend job (C-z under unix)
+    C-c C-z     suspend job (C-z under Unix)
     M-p         show previous commands
 
 # Text
@@ -163,7 +163,7 @@
     M C-\       indent region between cursor and mark
     M-m         move to first (non-space) char in this line
     M-^         attach this line to previous
-    M-;         formatize and indent comment
+    M-;         formats and indent comment
 # C, C++ and Java Modes
     M-a         beginning of statement
     M-e         end of statement
@@ -171,22 +171,22 @@
     M C-e       end of function
     C-c RETURN  Set cursor to beginning of function and mark at the end
     C-c C-q     indent the whole function according to indention style
-    C-c C-a     toggle modus in which after electric signs (like {}:\';./*) emacs does the indention
-    C-c C-d     toggle auto hungry mode in which emacs deletes groups of spaces with one del-press
+    C-c C-a     toggle modus in which after electric signs (like {}:\';./*) Emacs does the indention
+    C-c C-d     toggle auto hungry mode in which Emacs deletes groups of spaces with one del-press
     C-c C-u     go to beginning of this preprocessor statement
     C-c C-c     comment out marked area
 # More general
     M-x outline-minor-mode
                 collapses function definitions in a file to a mere {...}
     M-x show-subtree
-                If you are in one of the collapsed functions, this un-collapses it
+                If you are in one of the collapsed functions, this expands it
 # In order to achieve some of the feats coming up,
 # now you have to run etags *.c *.h *.cpp
 # (or what ever ending you source files have) in the source directory
     M-.         (Meta dot) If you are in a function call, this will take you to it\'s definition
     M-x tags-search ENTER
                 Searches through all you etaged
-    M-,         (Meta comma) jumps to the next occurence for tags-search
+    M-,         (Meta comma) jumps to the next occurrence for tags-search
     M-x tags-query-replace yum.
                 This lets you replace some text in all the tagged files
 

sheets/exim

@@ -45,7 +45,7 @@ exim -Mt <message-id> [ <message-id> ... ]
 # whether the retry time has been reached or not
 exim -M <message-id> [ <message-id> ... ]
 
-# Force message to fail and bounce as "cancelled by administrator"
+# Force message to fail and bounce as "canceled by administrator"
 exim -Mg <message-id> [ <message-id> ... ]
 
 # View message's headers

sheets/ffmpeg

@@ -23,6 +23,6 @@ ffmpeg -i ImageFile.jpg ImageFile.png
 # to the ffmpeg(1) man page for more information on these levels of logging.
 ffmpeg -v 0 -i IN_FILE OUT_FILE
 
-# If you want to see ongoing but not over-the-top statitics for the file on
+# If you want to see ongoing but not over-the-top statistics for the file on
 # which ffmpeg(1) is currently working, you can make use of the `-stats` flag.
 ffmpeg -stats -i IN_FILE OUT_FILE

sheets/find

@@ -37,7 +37,7 @@ find . -xdev \( -perm -4000 \) -type f -print0 | xargs -0 ls -l
 # times faster, and allows for more specificity.
 find -perm -4000 -type f -print0 | xargs -I '{}' -0 \ls -l '{}'
 
-# Find and remove files with case-senstive extension of `.txt`.
+# Find and remove files with case-sensitive extension of `.txt`.
 find [PATH] -name '*.txt' -exec rm '{}' \;
 # The above is much more efficiently written as shown below, as find(1) has its
 # own built-in delete function, not to mention a single rm(1) process was

sheets/finger

@@ -4,6 +4,6 @@
 # “.pgpkey” and “.forward” from the user's home directory.
 finger -s username
 
-# weather report in console (for nuremberg in this case)
+# weather report in console (for Nuremberg in this case)
 finger nuremberg@graph.no
 

sheets/git

@@ -86,7 +86,7 @@ git checkout master # <-- Checkout local master branch.
 git checkout -b new_branch # <-- Create and checkout a new branch.
 git merge upstream/master # <-- Merge remote into local repo.
 git show 83fb499 # <-- Show what a commit did.
-git show 83fb499:path/fo/file.ext # <-- Show the file as it was in 83fb499.
+git show 83fb499:path/to/file.ext # <-- Show the file as it was in 83fb499.
 git diff branch_1 branch_2 # <-- Check difference between branches.
 git log # <-- Show all of the commits.
 git status # <-- Show the changes from the last commit.

sheets/gpustat

@@ -3,6 +3,6 @@
 # It is a wrapper for nvidia-smi.
 # To install: `pip install gpustat`
 
-# show GPU statistsics with the processes PIDs and names
+# show GPU statistics with the processes PIDs and names
 gpustat -cp
 

sheets/hexdump

@@ -1,4 +1,4 @@
-# side-by-side hexadecimal and ascii view of the first 128 bytes of a file
+# side-by-side hexadecimal and ASCII view of the first 128 bytes of a file
 hexdump -C -n128 /etc/passwd
 
 # Convert a binary file to C Array

sheets/i3

@@ -57,7 +57,7 @@
 #
 # When creating new window, currently focused window
 # will be split in half and one half will be used by new window.
-# You can control whether it will split horiontally or
+# You can control whether it will split horizontally or
 # vertically with ◆+v or ◆+h.
 # You can focus multiple windows at once.
 # For example with this layout with two windows:
@@ -96,7 +96,7 @@
 # Default configuration path:
 /etc/i3/config
 
-# Keys can be binded with bindsym like this:
+# Keys can be bound with bindsym like this:
 bindsym $mod+4 workspace $ws4
 bindsym $mod+Shift+R exec custom-script-in-path.sh --flag1 --flag2
 bindcode 172 exec playerctl play-pause

sheets/iscsiadm

@@ -0,0 +1,21 @@
+# iscsiadm
+# open-iscsi administration utility
+
+# Discover targets at iscsi portal ADDR:PORT
+# Prints a list of available iscsi targets, example:
+#
+# <target-ip>:<port>  <IQN>
+# 10.10.10.42:3260,1 iqn.2007-10:iscsi.target0
+iscsiadm -m discovery -t sendtargets -p ADDR:PORT
+
+# login to target IQN at portal ADDR:PORT:
+iscsiadm -m node -T IQN -p ADDR:PORT --login
+
+# logout from specified target IQN:
+iscsiadm -m node -T IQN --logout
+
+# list active sessions:
+iscsiadm -m session
+
+# logout from all active sessions:
+iscsiadm -m node --logout

sheets/jq

@@ -97,7 +97,7 @@ jq --slurp '. | sort | .[]'
 # Group by a key - opposite to flatten
 jq 'group_by(.foo)'
 
-# Minimun value of an array
+# Minimum value of an array
 jq 'min'
 # See also min, max, min_by(path_exp), max_by(path_exp)
 

sheets/jslint

@@ -1,6 +1,6 @@
 # jslint
 #
-# The JavaScript Code Quality Tool written by Dougls Crockford
+# The JavaScript Code Quality Tool written by Douglas Crockford
 
 # to install jslint
 sudo npm install jslint -g

sheets/kafka-topics

@@ -1,6 +1,6 @@
 # kafka-topics
 #
-# Comamnd-line tool to manage Kafka topics
+# Command-line tool to manage Kafka topics
 
 # list topics
 kafka-topics --zookeeper localhost:2181 --list

sheets/links2

@@ -18,7 +18,7 @@ links2 -dump -width 80 duckduckgo.co.uk
 links2 -http.fake-user-agent 'Mozilla/5.0' duckduckgo.co.uk
 
 # Have links2(1) request not to be tracked (as if anyone respects this!?). The
-# `1` is a boolean integer, indicating to enable the aforetyped option. This
+# `1` is a boolean integer, indicating to enable the option. This
 # option is by default disabled, according the August 2006 man page.
 links2 -http.do-not-track 1 duckduckgo.co.uk
 

sheets/lse.sh

@@ -1,8 +1,8 @@
 # lse
-# Linux enumeration tools for pentesting and CTFs.
+# Linux enumeration tools for pen-testing and CTFs.
 # This project was inspired by https://github.com/rebootuser/LinEnum and uses
-# many of its tests. Unlike LinEnum, lse tries to gradualy expose the
-# information depending on its importance from a privesc point of view.
+# many of its tests. Unlike LinEnum, lse tries to gradually expose the
+# information depending on its importance from a privacy point of view.
 # GitHub repo: https://github.com/diego-treitos/linux-smart-enumeration.git
 
 # Basic usage
@@ -27,7 +27,7 @@
 # fst: File system related tests.
 # sys: System related tests.
 # sec: Security measures related tests.
-# ret: Recurren tasks (cron, timers) related tests.
+# ret: Recurrent tasks (cron, timers) related tests.
 # net: Network related tests.
 # srv: Services related tests.
 # pro: Processes related tests.

sheets/lvextend

@@ -2,17 +2,17 @@
 # Extends a logical volume in an existing volume group.
 # A volume group is a collection of logical and physical volumes.
 
-# Extend volume in volume mylv in groug vg0
+# Extend volume in volume mylv in group vg0
 # (defined by volume path /dev/vg0/mylv)
 # to 12 gigabyte:
 lvextend -L 12G /dev/vg0/mylv
 
-# Extend volume in volume mylv in groug vg0
+# Extend volume in volume mylv in group vg0
 # (defined by volume path /dev/vg0/mylv)
 # by 1 gigabyte:
 lvextend -L +1G /dev/vg0/mylv
 
-# Extend volume in volume mylv in groug vg0
+# Extend volume in volume mylv in group vg0
 # (defined by volume path /dev/vg0/mylv)
 # to use all of the unallocated space in the volume group vg0:
 lvextend -l +100%FREE /dev/vg0/mylv

sheets/mongo

@@ -21,7 +21,7 @@ mongo --shell my-script.js
 # and execute my-script.js after that
 mongo localhost:27017/myDatabase my-script.js
 
-# Evaluate a javascript expression on the database:
+# Evaluate a JavaScript expression on the database:
 mongo --eval 'JSON.stringify(db.foo.findOne())' database
 
 # See also:

sheets/mutt

@@ -64,8 +64,8 @@ mutt -s "hello" -b user2@example.com user@example.com
 #
 # shift+d (D)           : Delete messages using pattern
 # shift+t (T)           : Select messages using pattern
-# shift+u (U)           : Un-delete messages using pattern
-# ctrl+t                : de-selected messages using pattern
+# shift+u (U)           : Undelete messages using pattern
+# ctrl+t                : deselect messages using pattern
 # d                     : Delete message
 # N                     : Mark as new
 # C                     : Copy message to another folder(mailbox)

sheets/nm

@@ -24,7 +24,7 @@ nm  -S 1 | grep abc
 nm -D executable
 
 # Change the format of the nm output
-# (display the output of nm command in posix style)
+# (display the output of nm command in POSIX style)
 nm -u -f posix executable
 
 # Display only the external symbols of executable

sheets/nmap

@@ -73,8 +73,8 @@ nmap --script "(default or safe or intrusive) and not http-*"
 # -pT:443 => Scan only port 443 with TCP (T:)
 nmap -T5 --min-parallelism=50 -n --script "ssl-heartbleed" -pT:443 127.0.0.1
 
-# Show all informations (debug mode)
+# Show all information (debug mode)
 nmap -d ...
 
-# Discovert DHCP information on an interface
+# Discover DHCP information on an interface
 nmap --script broadcast-dhcp-discover -e eth0

sheets/pactl

@@ -0,0 +1,10 @@
+# pactl
+# Control a running PulseAudio sound server
+
+# Display a sorted and uniq-ified list of PulseAudio modules, using AWK.
+pactl list modules short | awk '{!Lines[$2]++} END {asorti(Lines, Sorted); for (Line in Sorted) print(Sorted[Line])}'
+
+# Load a module.
+pactl load-module MODULE
+# Unload a module.
+pactl unload-module MODULE

sheets/parted

@@ -1,4 +1,4 @@
-# create a new MBR/msdos partition table for BIOS systems
+# create a new MBR/MSDOS partition table for BIOS systems
 (parted) mklabel msdos
 
 # create a new GPT partition table for UEFI systems instead, use:

sheets/pg_top

@@ -1,5 +1,5 @@
 # pg_top
-# Display and update information about the top cpu PostgreSQL processes
+# Display and update information about the top CPU PostgreSQL processes
 
 # connect to port 5432 using user postgres, and database, ask for password
 pg_top -p 5432 -U postgres -d database -W
@@ -10,10 +10,10 @@ pg_top -p 5432 -U postgres -d database -W
 #      Display the actual query plan (EXPLAIN ANALYZE)
 #  E
 #      Display re-determined execution plan (EXPLAIN) of the SQL statement
-#      by a backend process
+#      by a back end process
 #  L
-#      Display the currently held locks by a backend process
+#      Display the currently held locks by a back end process
 #  Q
-#      Display the currently running query of a backend process
+#      Display the currently running query of a back end process
 #  X
 #      Display user index statistics.

sheets/prctl

@@ -6,7 +6,7 @@
 # Examine process limits and permissions:
 prctl ${PID}
 
-# Examine process limits and permissions in machine parseable format:
+# Examine process limits and permissions in machine parse-able format:
 prctl -P ${PID}
 
 # Get specific limit for a running process:

sheets/proc

@@ -1,6 +1,6 @@
 # /proc is a pseudo-filesystem containing running process information and more.
 
-# See the commandline arguments that started the process
+# See the command line arguments that started the process
 cat /proc/<pid>/cmdline
 
 # See the process's environment variables

sheets/read

@@ -23,7 +23,7 @@ read -n 1 -e -p 'Prompt: '
 # In this example, the [I]nput [F]ield [S]eperator is set to `=` for only the
 # `read` built-in, and the `-a` flag is used to split the input, per the
 # provided IFS, into an array. This then means the first index is the key and
-# the second index the value, which is ideal when parsing configurtion files.
+# the second index the value, which is ideal when parsing configuration files.
 while IFS='=' read -a Line; do
 	COMMANDS
 done < INPUT_FILE

sheets/resize2fs

@@ -1,6 +1,6 @@
 # resize2fs
 
-# ext2/ext3/ext4 file system resizer
+# ext2/ext3/ext4 file system resize tool
 
 # resize filesystem up to the block device size
 # make e2fsck /dev/xvdb1 before

sheets/rustup

@@ -1,19 +1,19 @@
 # rustup
-# The Rust toolchain installer
+# The Rust tool chain installer
 
-# update rustup toolchain
+# update rustup tool chain
 rustup update
 
 # install nightly build
 rustup install nightly
 
-# use rustc from nightly toolchain
+# use rustc from nightly tool chain
 rustup run nightly rustc --version
 
 # switch to nightly installation
 rustup default nightly
 
-# List all available targets for the active toolchain
+# List all available targets for the active tool chain
 rustup target list
 
 # Install the Android target
@@ -22,5 +22,5 @@ rustup target add arm-linux-androideabi
 # Run a shell configured for the nightly compiler
 rustup run nightly bash
 
-# Show which toolchain will be used in the current directory
+# Show which tool chain will be used in the current directory
 rustup show

sheets/scp

@@ -1,7 +1,7 @@
 # scp
 # Secure copy (remote file copy program)
 
-# Secury copies files from remote ADDR's APTH to the current-working-directory.
+# Securely copies files from remote ADDR's PATH to the current-working-directory.
 # By default here, port 22 is used, or whichever port is otherwise configured.
 scp ADDR:PATH ./
 

sheets/short

@@ -1,6 +1,6 @@
 # short (Bash-Snippets)
-# Unmasks shortended urls.
+# Unmasks shortened URLs.
 
-# Unmask the true url behind a shortened link
+# Unmask the true URL behind a shortened link
 short tinyurl.com/jhkj
 # Output: http://possiblemaliciouswebsiteornot.com

sheets/slsc

@@ -1,5 +1,5 @@
 # slsc
-# SpreadSheet for console, written using libslang (legacy)
+# Spreadsheet for console, written using libslang (legacy)
 
 # to install
 # * install libslang-dev first

sheets/sort

@@ -4,11 +4,14 @@
 # Return the contents of the British English dictionary, in reverse order.
 sort -r /usr/share/dict/british-english
 
-# Since sort(1) can filter out duplicate adjacent lines or fields, this example
-# therefore makes uniq(1) redundant. You should only ever use uniq(1) if you
-# need its functionality, or need uniqueness without sorting.
+# The GNU sort(1) command can also filter out adjacent duplicate lines and can
+# therefore overlap with the uniq(1) command. However, uniq(1) has some options
+# that sort(1) cannot do so refer to the man page for you situation if you 
+# require something beyond a basic uniqueness check. In addition, there is the
+# potential for parallizing the processing by piping sort(1) into uniq(1) for 
+# non trivial tasks.
 #
-# By default, sort(1) sorts lines or fields using the ASCI table. Here, we're
+# By default, sort(1) sorts lines or fields using the ASCII table. Here, we're
 # essentially getting alphanumeric sorting, where case is handled separately; -
 # this results in these words being adjacent to one another, thus duplicates
 # are removed.
@@ -17,7 +20,7 @@ sort -r /usr/share/dict/british-english
 printf '%s\n' this is a list of of random words with duplicate words | sort -u
 
 # Sort numerically. If you don't provide the `-n` flag, sort(1) will instead
-# sort by the ASCI table, as mentioned above, meaning it'll display as 1, 10, -
+# sort by the ASCII table, as mentioned above, meaning it'll display as 1, 10, -
 # 11, 2, 3, 4, etc.
 printf '%d\n' {1..9} 10 11 | sort -n
 

sheets/sqlcmd

@@ -0,0 +1,21 @@
+# sqlcmd
+# utility for MS SQL Server
+
+# connect to a database server with user
+sqlcmd -S localhost,1433 -U username
+
+# connect to a database server on specific db instance
+sqlcmd -S localhost,1433 -U username -P password -d target_db
+
+# change a password
+sqlcmd -U username -P oldpassword -Z newpassword
+
+# run a sql script against a database with variable (stdout)
+sqlcmd -S localhost,1433 -U username -v SOME_VARIABLE="foo" -i "/path/to/script.sql"
+
+# run a cmd line query and exit
+sqlcmd -S localhost,1433 -U username -Q "INSERT QUERY HERE"
+
+# check if a database exists using cmd line query (return 1 if True)
+sqlcmd -S localhost,1433 -U username -h -1 -W -Q "SET NOCOUNT ON;SELECT 1 FROM sys.databases WHERE [Name] = N'YOURDBNAME'"
+

sheets/ssh

@@ -27,13 +27,13 @@ ssh -X -t user@example.com 'chromium-browser'
 # Create a SOCKS proxy on localhost and port 9999.
 ssh -D 9999 user@example.com
 
-# Connect to server, but allow for X11 forwarding, while also using GZip
+# Connect to server, but allow for X11 forwarding, while also using Gzip
 # compression (can be much faster; YMMV), and using the `blowfish` encryption.
 # For more information, see: http://unix.stackexchange.com/q/12755/44856
 ssh -XCc blowfish user@example.com
 
 # Copy files and directories, via SSH, from remote host to the current working
-# directory, with GZip compression. An option for when `rsync` isn't available.
+# directory, with Gzip compression. An option for when `rsync` isn't available.
 #
 # This works by creating (not temporary!) a remote Tar archive, then piping its
 # output to a local Tar process, which then extracts it to STDOUT.
@@ -46,7 +46,7 @@ ssh -i some_id_rsa -o IdentitiesOnly=yes them@there:/path/
 # Temporarily disable `pubkey` authentication for this instance.
 ssh -o PubkeyAuthentication=no username@hostname.com
 
-# Mount a remote directory or filesystem, through SSH, to a local mountpoint.
+# Mount a remote directory or filesystem, through SSH, to a local mount point.
 # Install SSHFS from: https://github.com/libfuse/sshfs
 sshfs name@server:/path/to/folder /path/to/mount/point
 

sheets/swipl

@@ -1,7 +1,7 @@
 # swipl
 # SWI-Prolog is a versatile implementation of the Prolog language.
 
-# run plolog interpreter in interactive mode
+# run Prolog interpreter in interactive mode
 swipl
 
 # consult file.pl, run goal mygoal(3,foo)

sheets/systemd-sysvinit

@@ -1,4 +1,4 @@
-# SysVinit to Systemd Cheatsheet
+# SysVinit to Systemd Cheat sheet
 
 # Ways in which to control an available service.
 #
@@ -30,7 +30,7 @@ chkconfig SERVICE
 # SystemD:
 systemctl is-enabled SERVICE
 
-# Print a table of services, listing for which runlevel each is configured.
+# Print a table of services, listing for which run level each is configured.
 #
 # SysVinit:
 chkconfig --list
@@ -59,9 +59,9 @@ chkconfig SERVICE --add
 # SystemD:
 systemctl daemon-reload
 
-# Runlevel/Target -- Half the system.
+# Run level/Target -- Half the system.
 #
-# SysVinit Runlevel:        0
+# SysVinit Run level:        0
 # SystemD Target:           runlevel0.target
 #                           poweroff.target
 #
@@ -71,7 +71,7 @@ systemctl daemon-reload
 # SystemD Target:           runlevel1.target
 #                           rescue.target
 #
-# User-defined/Site-specific runlevels. By default, identical to 3.
+# User-defined/Site-specific run levels. By default, identical to 3.
 #
 # SysVinit Runlevel:        2, 4
 # SystemD Target:           runlevel2.target

sheets/tar

@@ -1,7 +1,7 @@
 # tar
 # GNU version of the tar archiving utility
 
-# An approach to backing up the current user's HOME, using tar(1) and GZip
+# An approach to backing up the current user's HOME, using tar(1) and Gzip
 # compression. Permissions (modes) will be preserved. The filename format will
 # be: UID:GID_DATE.tgz
 #

sheets/tmux

@@ -70,7 +70,7 @@ tmux attach-session -t name
 #
 #     setw -g mode-keys vi  # to switch into vi mode
 #
-#  Function                vi             emacs
+#  Function                Vi             Emacs
 #  -----------------------------------------------
 #  Back to indentation     ^              M-m
 #  Start selection         Space          C-space

sheets/todo

@@ -1,5 +1,5 @@
 # Todo (Bash-Snippets)
-# A simplistic commandline todo list
+# A simplistic command line to-do list
 
 # Add a task to your todo list
 todo -a This is an example task

sheets/tsp

@@ -1,5 +1,5 @@
 # tsp
-# task-spooler - A simple unix batch system to run commands in a queue
+# task-spooler - A simple Unix batch system to run commands in a queue
 
 # Run a job in the background 
 tsp pg_dump mydb

sheets/umask

@@ -5,8 +5,8 @@
 # mode creation mask") for only the current user, and only his or her current
 # session. The (one) leading zero is optional, unless you otherwise need it.
 #
-# This umask setting is actually recommended for security by RHEL, and is also
-# mentioned and I believe recommended in the Arch Linux Wiki.
+# This umask setting is actually recommended for security by major Linux distributions
+# like RHEL, Debian and Arch Linux.
 #
 # The result of '0077' being -- and I'll use standard octal with which we're
 # all probably familiar -- that all new files are created using the '600'

sheets/xfs_repair

@@ -1,7 +1,7 @@
 # xfs_repair
 # repair an XFS filesystem
 
-# rapair a XFS filesystem
+# repair a XFS filesystem
 xfs_repair /dev/dm-0
 
 # last resort option:

sheets/xinput

@@ -25,7 +25,7 @@ xinput --set-prop 8 157 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.
 xinput disable [touchscreen XID]
 
 # Disable middle mouse button click
-# Numbers are what you do with the first, second, and third (ie, left, middle, right) mouse buttons.
+# Numbers are what you do with the first, second, and third (i.e., left, middle, right) mouse buttons.
 # 1 0 3 means that the left button should do a left click (action 1),
 #                  the middle button should do nothing,
 #              and the right button should do a right click (action 3).

sheets/xkb

@@ -12,6 +12,6 @@ export GTK_IM_MODULE=$input_module
 export XMODIFIERS=@im=$input_module
 export QT_IM_MODULE=$input_module
 EOF
-# And you probly need to start:
+# And you probably need to start:
 # ibus-daemon --xim --verbose --daemonize --replace
 

sheets/xm

@@ -57,7 +57,7 @@ xm resume
 # Similar to suspend except with user definable state file
 xm save
 
-# Similar to resume except restoreable with exports that used the save verb
+# Similar to resume except can be restored with exports that used the save verb
 xm restore
 
 # Dumps core per domain

sheets/xset

@@ -7,7 +7,7 @@ xset s off
 # Change time before which the screen is blanked, to 3,600 seconds (1 hour).
 xset s 3600 3600
 
-# Turn off Display Power Management Signaling. To instead enable DPMS, the `-`
+# Turn off Display Power Management Signalling. To instead enable DPMS, the `-`
 # character is simply changed to `+`.
 xset -dpms
 

sheets/yay

@@ -21,7 +21,7 @@ yay -Y --gendb
 # and use PKGBUILD modification time and not version to determine update
 yay -Syu --devel --timeupdate
 
-# instalation
+# installation
 git clone https://aur.archlinux.org/yay.git
 cd yay
 makepkg -si

sheets/yq

@@ -24,7 +24,7 @@ yq r sample.yml spec.metadata[name==myapp]
 # Collect results into an array
 yq r sample.yaml --collect a.*.animal
 
-# Read from the 2nd docuemnt
+# Read from the 2nd document
 yq r -d1 sample.yaml b.c
 
 # Validate a document

sheets/yq_v4

@@ -15,7 +15,7 @@ yq eval \
 yq eval '.a |= .b' sample.yml
 
 # Update multiple nodes. a and c are siblings.
-yq eval '(.a, .c) |= "potatoe"' sample.yml
+yq eval '(.a, .c) |= "potato"' sample.yml
 
 # Update selected results.
 # Only update a's children with value=='apple' to 'frog'.

sheets/ytview

@@ -1,10 +1,10 @@
 # ytview (Bash-Snippets)
-# search and play youtube videos right from the terminal
+# search and play YouTube videos right from the terminal
 
-# Search for youtube videos by title
+# Search for YouTube videos by title
 ytview This is my search query
 
-# Search for youtbe videos by specifying a channel
+# Search for YouTube videos by specifying a channel
 ytview -c numberphile
 
 # After using one of the two above commands you will be able