Sohang Chopra sohang3112

git add -p is your friend

git add -p is basically "git add partial (or patch)"

Patch mode allows you to stage parts of a changed file, instead of the entire file. This allows you to make concise, well-crafted commits that make for an easier to read history. This feature can improve the quality of the commits. It also makes it easy to remove parts of the changes in a file that were only there for debugging purposes - prior to the commit without having to go back to the editor.

It allows you to see the changes (delta) to the code that you are trying to add, and lets you add them (or not) separately from each other using an interactive prompt. Here's how to use it:

from the command line, either use

git add -p

Math

.s - Show the stack
+, -, *, mod - Math operators
/mod - performs both / and mod

Stack manipulation

drop and 2drop - drop a stack item (once / twice)
dup - duplicate a stack item
rot - rotate the stack

Opening and closing an SSH tunnel in a shell script the smart way

I recently had the following problem:

From an unattended shell script (called by Jenkins), run a command-line tool that accesses the MySQL database on another host.
That tool doesn't know that the database is on another host, plus the MySQL port on that host is firewalled and not accessible from other machines.

We didn't want to open the MySQL port to the network, but it's possible to SSH from the Jenkins machine to the MySQL machine. So, basically you would do something like

ssh -L 3306:localhost:3306 remotehost

Haskell vs Clojure

The JSON data is in the following format

{
    "Genesis": {
        "1": {
            "1": "In the beginning..." ,
            "2": "..."

	; The stack pointer is going to be an index into the stack, and the
	; stack is an array of words. The alternative would be to have the
	; stack pointer me a pointer to memory, but this is perhaps a bit
	; nicer, as where the stack actually lives is totally irrelevant.

	@stack = global [1000 x i64] undef
	@sp = global i64 undef;

	; Now we have the basic stack operations: push, pop, and peek. As can
	; be seen from the definitions, LLVM is typed, which is really nice as

	from fabric.api import local
	import pip

	def freeze ():
	local("pip freeze > requirements.txt")
	local("git add requirements.txt")
	local("git commit -v")

	def upgrade ():
	for dist in pip.get_installed_distributions():

	;; After connecting an nrepl client repl to an nrepl server, some
	;; output will still appear on stdout from the server.

	;; Try these snippets - they will both produce output on the nrepl server
	;; Java libraries commonly do both these things.

	(.println System/out "Hello stdout.")
	(.start (Thread. #(println "Hello from a new thread.")))

	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

	(require 2htdp/universe)
	(require 2htdp/image)

	; Copyright 2012, John Clements ([email protected])
	;
	; Licensed under the Apache License, Version 2.0 (the "License");
	; you may not use this file except in compliance with the License.
	; You may obtain a copy of the License at
	;
	; http://www.apache.org/licenses/LICENSE-2.0

	20 chars Constant namestring-len
	Create namestring namestring-len allot

	: input ( buf-addr buf-len prompt-addr promt-len -- buf-add len )
	\ prompt user for string
	cr type over swap accept ;

	: get-age ( -- n )
	0.
	BEGIN ( d )


	: sqrt-closer (square guess -- square guess adjustment) 2dup / over - 2 / ;
	: sqrt ( square -- root ) 1 begin sqrt-closer dup while + repeat drop nip ;