#-# #-# Pointcut #-# A pointcut is a program element that picks out join points and exposes data from the execution context of those join points. Pointcuts are used primarily by advice. They can be composed with boolean operators to build up other pointcuts. any type and number of args ─┐ method ─┐ │ class ─┐ │ │ │ │ │ @Pointcut(“execution(public * com.demo..(..))”) │ │ │ │ │ └─ any return type

#-# #-# Source code comments #-# Parameter dezambiguation ┌─ execute with superuser rights │ ┌─ change file mode │ │ ┌─ path to file sudo chmod a+rx file │ │└─ execution right │ └─ read right └─ all users #-# #-# Command line display #-# Statuses [?] - unknown [✔] - success [✖] - failure Directory tree root ├── CVS │ ├── Entries │ ├── Repository │ └── Root ├── Makefile

#-# #-# Operations #-# #-# Transfer Name Comment Code Operation O D I T S Z A P C MOV Move (copy) MOV dest,source dest:=source . . . . . . . . . XCHG Exchange XCHG op1,op2 op1:=op2, op2:=op1 . . . . . . . . . STC Set carry STC CF:=1 . . . . . . . . 1 CLC Clear carry CLC CF:=0 . . .

#-# #-# Variables #-# #-# String manipulation Command Description ${varname:-word} If varname exists and isn’t null, return its value; otherwise return word ${varname:=word} If varname exists and isn’t null, return its value; otherwise set it word and then return its value ${varname:?message} If varname exists and isn’t null, return its value; otherwise print varname, followed by message and abort the current command or script ${varname:+word} If varname exists and isn’t null, return word; otherwise return null

#-# #-# Big-O complexities for common algorithms #-# #-# Data Structure Operations Data Structure Time Complexity Space Complexity Average Worst Worst ------- ----- ----- Access Search Insertion Deletion Access Search Insertion Deletion ------ ------ --------- -------- ------ ------ --------- -------- Array O(1) O(n) O(n) O(n) O(1) O(n) O(n) O(n) O(n) Stack O(n) O(n) O(1) O(1) O(n) O(n) O(1) O(1) O(n) Singly-Linked List O(n) O(n) O(1) O(1) O(n) O(n) O(1) O(1) O(n)

#-# #-# Filesystem #-# mklink /j source destination

#-# #-# Box Model #-# ┌───────────────────────────────────────────┐ │ │ │ ┌───────────────────────────────────┐ │ │ │ │ │ │ │ ┌───────────────────────────┐ │ │ │ │ │ padding ──┼───┼───┼── Clears an area around the content. │ │ │ ┌───────────────────┐ │ │ │ The padding is transparent. │ │ │ │ │ │ │ │ │ │ │ │ content ────┼───┼───┼───┼── The content of the box, │ │ │ │ │ │ │ │ where text and images appear.

#-# #-# Keyboard shortcuts #-# #-# Debugging Windows OS X Shortcut F5 F5 Step Into F6 F6 Step Over F7 F7 Step Return F8 F8 Resume F11 F11 Debug Last Launched Ctrl+F11 Cmd+F11 Run Last Launched Ctrl+R Cmd+R Run to Line Ctrl+Shift+B Cmd+Shift+B Toggle Breakpoint on Line #-# Navigation Windows OS X Shortcut F3 F3 Format Source Ctrl+Shift+G Cmd+Shift+G Find Reference Ctrl+Shift+R Cmd+Shift+R Open Resource Ctrl+Shift+T Cmd+Shift+T Open Type Ctrl+H Cmd+H Open Search Dialog

#-# #-# Directives #-# #-# Strings Directive Description boolean Converts string to boolean (true, false). cap_first Capita­lizes first word of string. capitalize Capita­lizes every word in string properly. chop_l­ine­break Removes line-break from end of string. contains (subst­ring) Checks if string contains substring. date, time, datetime Converts string to date/t­ime­/da­tetime based on *_format. ends_with (subst­ring) Checks if string ends with substring. ensure­_en­ds_with (subst­ring) Returns string with substring appended if not already there.

#-# #-# Configuration #-# Define the author name to be used for all commits by the current user. git config –global user.name Define the author email to be used for all commits by the current user. git config –global user.email Create shortcut for a Git command. E.g. alias.glog “log –graph –oneline” will set “git glog” equivalent to “git log –graph –oneline” git config –global alias. Set text editor used by commands for all users on the machine.

#-# #-# Command line #-# gradle [option…] [task…] #-# Options Option Description -?, -h, –help Shows a help message. -a, –no-rebuild Do not rebuild project dependencies. –all Shows additional detail in the task listing. -b, –build-file Specifies the build file. -c, –settings-file Specifies the settings file. –console Specifies which type of console output to generate (plain/auto/rich). –continue Continues task execution after a task failure. –configure-on-demand Only relevant projects are configured in this build run.

#-# #-# Variables #-# def x = 1 println x x = new java.util.Date() println x x = -3.1499392 println x x = false println x x = “Groovy!” println x #-# #-# Collections #-# Creating an empty list def technologies = [] Adding elements to the list technologies.add(“Grails”) technologies « “Groovy” // Left shift adds, and returns the list technologies.addAll([“Gradle”,“Griffon”]) Removing elements from the list technologies.remove(“Griffon”) technologies = technologies - ‘Grails’

#-# #-# Command line #-# #-# Namenode Command Description hadoop namenode -format Format HDFS filesystem from Namenode. hadoop namenode -upgrade Upgrade the NameNode. start-dfs.sh Start HDFS Daemons. stop-dfs.sh Stop HDFS Daemons. start-mapred.sh Start MapReduce Daemons. stop-mapred.sh Stop MapReduce Daemons. hadoop namenode -recover -force Recover namenode metadata after a cluster failure (may lose data). #-# Health Command Description hadoop fsck / Filesystem check on HDFS. hadoop fsck / -files Display files during check.