Fix comment length in all first-level cheat sheets

*  sheets/MegaCli
*  sheets/az
*  sheets/azure
*  sheets/blktrace
*  sheets/emacs
*  sheets/exim
*  sheets/go
*  sheets/ipython
*  sheets/jq
*  sheets/nmap
*  sheets/perl
*  sheets/psql
*  sheets/redis
*  sheets/sed
*  sheets/smartctl
*  sheets/solidity
*  sheets/yq_v4

sheets/MegaCli

@@ -1,5 +1,6 @@
-# MegaCli introduced by LSI as a command line administration of LSI MegaRaid controllers.
-# With megacli we can create physical raids, gather info about raids and monitor raids.
+# MegaCli
+# A command line administration of LSI MegaRaid controllers.
+# It allows to create physical raids, gather info about raids and monitor raids.
 
 # Install MegaCLI
 yum install MegaCli # CentOS
@@ -21,4 +22,3 @@ MegaCli -PDInfo -PhysDrv [E:S] -aALL
 
 # Battery backup information
 MegaCli -AdpBbuCmd -aALL
-

sheets/az

@@ -4,11 +4,14 @@
 # Install Azure CLI 2.0 with one curl command.
 curl -L https://aka.ms/InstallAzureCli | bash
 
-# create a resource group named "MyResourceGroup" in the westus2 region of Azure
-az group create -n MyResourceGroup -l westus2
+# create a resource group named "MyRG" in the 'westus2' region
+az group create -n MyRG -l westus2
 
-# create a Linux VM using the UbuntuTLS image, with two attached storage disks of 10 GB and 20 GB
-az vm create -n MyLinuxVM -g MyResourceGroup --ssh-key-value $HOME/.ssh/id_rsa.pub --image UbuntuLTS --data-disk-sizes-gb 10 20
+# create a Linux VM using the UbuntuTLS image,
+# with two attached storage disks of 10 GB and 20 GB
+az vm create -n MyLinuxVM -g MyRG \
+    --ssh-key-value $HOME/.ssh/id_rsa.pub --image UbuntuLTS \
+    --data-disk-sizes-gb 10 20
 
 # list VMs
 az vm list --output table
@@ -16,28 +19,28 @@ az vm list --output table
 # list only VMs having distinct state
 az vm list -d --query "[?powerState=='VM running']" --output table
 
-# delete VM (with the name MyLinuxVM in the group MyResourceGroup)
-az vm delete -g MyResourceGroup -n MyLinuxVM --yes
+# delete VM (with the name MyLinuxVM in the group MyRG)
+az vm delete -g MyRG -n MyLinuxVM --yes
 
 # Delete all VMs in a resource group
-az vm delete --ids $(az vm list -g MyResourceGroup --query "[].id" -o tsv)
+az vm delete --ids $(az vm list -g MyRG --query "[].id" -o tsv)
 
 # Create an Image based on a running VM
-az vm deallocate -g MyResourceGroup -n MyLinuxVM
-az vm generalize -g MyResourceGroup -n MyLinuxVM
-az image create --resource-group MyResourceGroup --name MyTestImage --source MyLinuxVM
+az vm deallocate -g MyRG -n MyLinuxVM
+az vm generalize -g MyRG -n MyLinuxVM
+az image create --resource-group MyRG --name MyTestImage --source MyLinuxVM
 
 # Running VM based on a VHD
 az storage blob upload --account-name "${account_name}"  \
-   --account-key "${account_key}" --container-name "${container_name}" --type page \
-   --file "${file}" --name "${vhd_name}"
+   --account-key "${account_key}" --container-name "${container}" --type page \
+   --file "${file}" --name "${vhd}"
 az disk create \
-   --resource-group ${resource_group} \
+   --resource-group "${resource_group}" \
    --name myManagedDisk \
-   --source https://${account_name}.blob.core.windows.net/${container_name}/${vhd_name}
+   --source "https://${account_name}.blob.core.windows.net/${container}/${vhd}"
 
 # open port
-az vm open-port --resource-group MyResourceGroup --name MyLinuxVM --port 443 --priority 899
+az vm open-port --resource-group MyRG --name MyLinuxVM --port 443 --priority 899
 
 # Show storage accounts
 az storage account list --output table
@@ -46,7 +49,8 @@ az storage account list --output table
 az storage container list --account-name mystorageaccount --output table
 
 # Show blobs in a container
-az storage blob list --account-name mystorageaccount --container-name mycontainer  --output table
+az storage blob list --account-name mystorageaccount \
+    --container-name mycontainer  --output table
 
 # list account keys
 az storage account keys list  --account-name STORAGE_NAME --resource-group RESOURCE_GROUP
@@ -62,8 +66,8 @@ az disk list --output table
 
 # Copy blob
 az storage blob copy start \
-    --source-uri 'https://md-ldh5nknx2rkz.blob.core.windows.net/jzwuuuzzapn0/abcd?sv=2017-04-17&sr=b&si=68041718-6828-4f5e-9e6e-a1b719975062&sig=XXX' \
-    --account-key XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX== \
+    --source-uri 'https://xxx.blob.core.windows.net/jzwuuuzzapn0/abcd?...' \
+    --account-key XXXXXXXXXX== \
     --account-name destaccount \
     --destination-container vms \
     --destination-blob DESTINATION-blob.vhd
@@ -81,7 +85,8 @@ az vm list-ip-addresses --output table
 az snapshot create --resource-group IC-EXASOL-001 --source vm1-disk1 -n vm1-snap1
 
 # create SAS url for a snapshot
-az snapshot grant-access --resource-group IC-EXASOL-001 --name vm1-snap1 --duration-in-seconds 36000 --query '[accessSas]' -o tsv
+az snapshot grant-access --resource-group IC-EXASOL-001 --name vm1-snap1\
+    --duration-in-seconds 36000 --query '[accessSas]' -o tsv
 
 # attach disk
 az vm disk attach --vm-name vm1 -g RESOURCE_GROUP --disk DISK1_ID

sheets/azure

@@ -10,13 +10,14 @@ azure login
 azure login -u <your organizational ID email address>
 
 # This will login in using a service principal
-azure login -u "<service-principal-id>" -p "<key>" --service-principal --tenant "<tenant-id>"
+azure login -u "<principal>" -p "<key>" --service-principal --tenant "<tenant>"
 
 # find images with Linux in name
 azure vm image list | grep "Linux"
 
 # start a new VM (in asm mode)
-azure vm create ${vm_name} ${image_name} -u ${azureuser} -p "${password}" -z "Small" -e -l "West US"
+azure vm create ${vm_name} ${image_name} -u ${azureuser} \
+  -p "${password}" -z "Small" -e -l "West US"
 
 # List VMs disks
 azure vm disk list
@@ -24,24 +25,28 @@ azure vm disk list
 # Remove all disks of VMs labeled with LABEL
 for disk in $(azure vm disk list | grep LABEL | awk '{print $2}')
 do
-    azure vm disk delete --blob-delete "$disk"
+  azure vm disk delete --blob-delete "$disk"
 done
 
 # Create storage account $myacct in location 'West US'
-azure storage account create ${storage_account} --label ${storage_account} --location 'West US'
+azure storage account create ${stor_acc} \
+  --label ${stor_acc} --location 'West US'
 
 # Set default account environment variables
 export AZURE_STORAGE_ACCOUNT=$account_name
 export AZURE_STORAGE_ACCESS_KEY=$account_key
 
 # Create a VM image based on a storage file
-azure vm image create ${image_name} --os linux  -l 'West Europe' --blob-url https://${storage_account}.blob.core.windows.net:443/vms/${image_name}.vhd -v
+azure vm image create ${image_name} --os linux  -l 'West Europe' \
+  --blob-url https://${stor_acc}.blob.core.windows.net:443/vms/${image}.vhd -v
 
 # Share a file (a vm image for example) with the world:
-azure storage blob sas create -a ${storage_account} --container ${container} --blob ${filename} --permissions r
+azure storage blob sas create -a ${stor_acc} \
+  --container ${container} --blob ${filename} --permissions r
 
 # Download a file from a blob storage using curl/wget
-# values of the header variables can be calculated like here: https://gist.github.com/jrwren/ff46f4ba177f042ccdc48c080c198f60
+# values of the header variables can be calculated like here:
+# https://gist.github.com/jrwren/ff46f4ba177f042ccdc48c080c198f60
 curl -v \
   -H "$x_ms_date_h" \
   -H "$x_ms_version_h" \

sheets/blktrace

@@ -1,5 +1,6 @@
 # blktrace
-# blktrace is a block layer IO tracing mechanism which provides detailed information about request queue operations up to user space
+# A block layer IO tracing mechanism which provides detailed information
+# about request queue operations up to user space
 
 # trace PC (non-filesystem requests, PC) on the /dev/sdb disk.
 # blkparse generates human-readable formatting

sheets/emacs

@@ -180,7 +180,8 @@
                 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
-# In order to achieve some of the feats coming up now you have to run etags *.c *.h *.cpp
+# 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

sheets/exim

@@ -22,7 +22,8 @@ exiqgrep -f [user]@domain
 # Search the queue for messages from a specific recipient
 exiqgrep -r [user]@domain
 
-# Print messages older than the specified number of seconds (1 day = 86400 seconds)
+# Print messages older than the specified number of seconds
+# (1 day = 86400 seconds)
 exiqgrep -o 86400
 
 # Print messages younger than the specified number of seconds
@@ -40,7 +41,8 @@ exim -Mf <message-id> [ <message-id> ... ]
 # Thaw (unfreeze) a message
 exim -Mt <message-id> [ <message-id> ... ]
 
-# Deliver message, whether it's frozen or not, whether the retry time has been reached or not
+# Deliver message, whether it's frozen or not,
+# 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"

sheets/go

@@ -1,4 +1,5 @@
-# Go is a free and open source programming language created at Google
+# Go
+# A free and open source programming language created at Google
 # and go is a tool for managing go source code.
 
 # Download and install a package, specified by its import path:
@@ -10,7 +11,8 @@ go run file.go
 # Compile the package present in the current directory:
 go build
 
-# Execute all test cases of the current package (files have to end with _test.go):
+# Execute all test cases of the current package
+# (files have to end with _test.go):
 go test
 
 # Compile and install the current package:

sheets/ipython

@@ -1,10 +1,10 @@
-# create a ipython profile
+# Create a ipython profile
 ipython profile create profile_name
 
-# use specified profile
+# Use specified profile
 ipython --profile=${profile_name}
 
-# list objects, functions, etc. that have been added in the current namespace,
+# List objects, functions, etc. that have been added in the current namespace,
 # as well as modules that have been imported
 %who
 
@@ -12,7 +12,8 @@ ipython --profile=${profile_name}
 # so that they can be executed all together using the assigned name
 %macro
 
-# This will open an editor (whatever the shell variable EDITOR is set to, see above, or vi/vim if no variable is set)
+# This will open an editor (whatever the shell variable EDITOR is set to,
+# see above, or vi/vim if no variable is set)
 # containing the specified material, based on what arguments are provided,
 # and will execute that code once the editor is exited
 %edit
@@ -20,23 +21,25 @@ ipython --profile=${profile_name}
 # This lists all ipython magic commands
 %lsmagic
 
-# store variables, functions, etc. that you've defined in your .ipython/ipythonrc file for use in future sessions
+# Store variables, functions, etc. that you've defined in .ipython/ipythonrc
+# for use in future sessions
 %store
 
-# configure ipython to automatically open the python debugger pdb when an error occurs
+# Configure ipython to automatically open the python debugger pdb
+# when an error occurs
 %pdb
 
-# timing functions to see how long expressions take to execute
+# Timing functions to see how long expressions take to execute
 %time
 %timeit
 
-# to log ipython input and/or output to files
+# Log ipython input and/or output to files
 %logstart
 %logon
 %logoff
 %logstate
 
-# (to change directories, manipulate directory stacks, and create directory "bookmarks")
+# Change directories, manipulate directory stacks, create directory "bookmarks"
 %cd
 %pushd
 %popd

sheets/jq

@@ -8,7 +8,8 @@ jq
 # (or all key-value pairs from objects) in a JSON file:
 jq .[]
 
-# Read JSON objects from a file into an array, and output it (inverse of jq .[]):
+# Read JSON objects from a file into an array, and output it
+# (inverse of jq .[]):
 jq --slurp
 
 # Output the first element in a JSON file:
@@ -42,7 +43,8 @@ jq 'map({ a, b })'
 #     => [ { "a": 1, "b": 2 }, ...]
 
 # Converting arbitrary data to json
-jq -r '(map(keys) | add | unique | sort) as $cols | .[] as $row | $cols | map($row[.]) | @csv'
+jq -r '(map(keys) | add | unique | sort) as $cols \
+        | .[] as $row | $cols | map($row[.]) | @csv'
 #
 #     [ { "foo": 1, "bar": 2}, { "foo": 3, "baz": 4}]
 #
@@ -150,4 +152,3 @@ jq '.[] | [.foo, .bar] | @csv' -r
 #
 #     [{ "foo": 1, "bar": 2, "baz":3 }]
 #     => 1,2
-

sheets/nmap

@@ -4,8 +4,10 @@ nmap [target]
 # Scan from a list of targets:
 nmap -iL [list.txt]
 
-# Scan port for all available A records (useful when multiple A records are returned by the DNS server)
-nmap --script resolveall --script-args newtargets,resolveall.hosts=[target] -p [port]
+# Scan port for all available A records
+# (useful when multiple A records are returned by the DNS server)
+nmap --script resolveall \
+    --script-args newtargets,resolveall.hosts=[target] -p [port]
 
 # iPv6:
 nmap -6 [target]
@@ -49,10 +51,12 @@ nmap -sP 192.168.0.0/24
 # Use some script:
 nmap --script default,safe
 
-# Loads the script in the default category, the banner script, and all .nse files in the directory /home/user/customscripts.
+# Loads the script in the default category, the banner script,
+# and all .nse files in the directory /home/user/customscripts.
 nmap --script default,banner,/home/user/customscripts
 
-# Loads all scripts whose name starts with http-, such as http-auth and http-open-proxy.
+# Loads all scripts whose name starts with http-,
+# such as http-auth and http-open-proxy.
 nmap --script 'http-*'
 
 # Loads every script except for those in the intrusive category.
@@ -61,7 +65,8 @@ nmap --script "not intrusive"
 # Loads those scripts that are in both the default and safe categories.
 nmap --script "default and safe"
 
-# Loads scripts in the default, safe, or intrusive categories, except for those whose names start with http-.
+# Loads scripts in the default, safe, or intrusive categories,
+# except for those whose names start with http-.
 nmap --script "(default or safe or intrusive) and not http-*"
 
 # Scan for the heartbleed

sheets/perl

@@ -16,10 +16,12 @@ perl -Mmodule -e perl_statement
 # Run a Perl script in debug mode, using perldebug:
 perl -d script.pl
 
-# Loo[p] over all lines of a file, editing them [i]n-place using a find/replace [e]xpression:
+# Loo[p] over all lines of a file, editing them [i]n-place
+# using a find/replace [e]xpression
 perl -p -i -e 's/find/replace/g' filename
 
-# Run a find/replace expression on a file, saving the original file with a given extension:
+# Run a find/replace expression on a file,
+# saving the original file with a given extension:
 perl -p -i'.old' -e 's/find/replace/g' filename
 
 # See also:

sheets/psql

@@ -1,19 +1,23 @@
 # psql
 # PostgreSQL command-line client.
 
-# Connect to database. It connects to localhost using default port 5432 with default user as currently logged in user:
+# Connect to database.
+# It connects to localhost using default port 5432
+# with default user as currently logged in user
 psql database
 
-# Connect to database on given server host running on given port with given username, without a password prompt:
+# Connect to database on given server host running on given port
+# with given username, without a password prompt
 psql -h host -p port -U username database
 
-# Connect to database; user will be prompted for password:
+# Connect to database; user will be prompted for password
 psql -h host -p port -U username -W database
 
-# Execute a single SQL query or PostgreSQL command on the given database (useful in shell scripts):
+# Execute a single SQL query or PostgreSQL command
+# on the given database (useful in shell scripts)
 psql -c 'query' database
 
-# Execute commands from a file on the given database:
+# Execute commands from a file on the given database
 psql database -f file.sql
 
 # See also:

sheets/redis

@@ -1,5 +1,6 @@
 # redis
-# Redis is an open source (BSD licensed), in-memory data structure store, used as a database, cache and message broker
+# Redis is an open source (BSD licensed), in-memory data structure store,
+# used as a database, cache and message broker
 
 # connect to redis server (port 6397)
 nc localhost 6397

sheets/sed

@@ -1,14 +1,17 @@
+# sed
+# A stream editor. Used to perform basic text transformations
+
 # Preview a file edit, via substitution.
-sudo sed 's/Name=Xfce Session/Name=Xfce_Session/' /usr/share/xsessions/xfce.desktop
+sudo sed 's/Name=Xfce Session/Name=Xfce_Session/' FILE
 
-# Replace the same string more than once per line (appending g flag), via substitution.
-sudo sed 's/Name=Xfce Session/Name=Xfce_Session/g' /usr/share/xsessions/xfce.desktop
+# Replace the same string more than once per line (g flag)
+sudo sed 's/Name=Xfce Session/Name=Xfce_Session/g' FILE
 
-# Edit a file (adding -i flag), via substitution, in-place; changes are made to the file(s).
-sudo sed -i 's/Name=Xfce Session/Name=Xfce_Session/' /usr/share/xsessions/xfce.desktop
+# Edit a file (adding -i flag), in-place; changes are made to the file(s).
+sudo sed -i 's/Name=Xfce Session/Name=Xfce_Session/' FILE
 
 # It can become necessary to escape special characters in your string.
-sed -i 's/\/path\/to\/somewhere\//\/path\/to\/anotherplace\//' /tmp/filetoedit
+sed -i 's/\/path\/to\/somewhere\//\/path\/to\/anotherplace\//' FILE
 
 # Change your sed delimiter to a pipe to avoid escaping slashes.
-sed -i 's|/path/to/somewhere/|/path/to/anotherplace/|' /tmp/filetoedit
+sed -i 's|/path/to/somewhere/|/path/to/anotherplace/|' FILE

sheets/smartctl

@@ -4,7 +4,7 @@
 # Quickly check the overall health of a drive
 smartctl -H /dev/sda
 
-# Obtain information on the drive: view the type of drive, its serial number, and so forth
+# Obtain information on the drive: type of drive, serial number, etc.
 smartctl -i /dev/sda
 
 # initiate short tests for the drive

sheets/solidity

@@ -1,7 +1,9 @@
-# Solidity is a contract-oriented, high-level language for implementing smart contracts.
+# Solidity
+# A contract-oriented, high-level language for implementing smart contracts.
 # It is designed to target the Ethereum Virtual Machine (EVM).
 
-# To create a contract, declare which solidity version the source code is written for
+# To create a contract,
+# declare which solidity version the source code is written for
 pragma solidity ^0.4.0;
 
 # See also:

sheets/yq_v4

@@ -7,15 +7,18 @@
 yq eval '.spec.template' example.yml
 
 # Assign spec.selector.matchLabels to spec.template.metadata.labels 
-yq eval '.spec.selector.matchLabels |= .spec.template.metadata.labels' example.yaml
+yq eval \
+    '.spec.selector.matchLabels |= .spec.template.metadata.labels' example.yaml
 
-# Update parent to be the child value. b is a's child. '|=' means the . on the right is relative to the left.
+# Update parent to be the child value. b is a's child.
+# '|=' means the . on the right is relative to the left.
 yq eval '.a |= .b' sample.yml
 
 # Update multiple nodes. a and c are siblings.
 yq eval '(.a, .c) |= "potatoe"' sample.yml
 
-# Update selected results. Only update a's children with value=='apple' to 'frog'.
+# Update selected results.
+# Only update a's children with value=='apple' to 'frog'.
 yq eval '.a[] | select(. == "apple") |= "frog"' sample.yml
 
 # Match with boolean operator 'or'.