MohamedAlaa

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

leipzig

function mycd()
{
    #if this directory is writable then write to directory-based history file
    #otherwise write history in the usual home-based history file                    
    tmpDir=$PWD
    echo "#"`date '+%s'` >> $HISTFILE
    echo $USER' has exited '$PWD' for '$@ >> $HISTFILE
    builtin cd "$@" # do actual cd
    if [ -w $PWD ]; then export HISTFILE="$PWD/.dir_bash_history"; touch $HISTFILE; chmod --silent 777 $HISTFILE;
    else export HISTFILE="$HOME/.bash_history";

kellyrob99

@Grab(group = 'net.sf.opencsv', module = 'opencsv', version = '2.3')
import au.com.bytecode.opencsv.CSVReader
import au.com.bytecode.opencsv.CSVParser
import au.com.bytecode.opencsv.CSVWriter

def TEST_FILE_NAME = 'test.csv'
def TEST_OUTPUT_FILE_NAME = 'testOut.csv'

List<String[]> rows = new CSVReader(new FileReader(new File(TEST_FILE_NAME)), CSVParser.DEFAULT_SEPARATOR, CSVParser.DEFAULT_ESCAPE_CHARACTER, CSVParser.DEFAULT_QUOTE_CHARACTER, 1).readAll()
def rowsOver100 = rows.findAll {it[1].toInteger() > 100}

prasoonsharma

# DATA FRAME OPERATIONS IN R

# Create data frame
# A dataset is ~ table (list of vectors)
id <- c(1,2,3)
name <- c("John", "Kirk", "AJ")
age <- c(21,27,18)
employees <- data.frame(ID=id, Name=name, Age=age)
employees

iangreenleaf

#!/bin/bash

### ABOUT
### Runs rsync, retrying on errors up to a maximum number of tries.
### Simply edit the rsync line in the script to whatever parameters you need.

# Trap interrupts and exit instead of continuing the loop
trap "echo Exited!; exit;" SIGINT SIGTERM

MAX_RETRIES=50