Merge branch 'master' into install-ubuntu

Author: narendasan

CONTRIBUTING.md

@@ -2,6 +2,8 @@
 
 > Contribution Guide from https://github.com/thoughtbot/til
 
+*All TILs are located in _til/*
+
 When you learn something,
 add a Markdown file to
 this repo explaining it in concise terms.
@@ -42,7 +44,7 @@ You can quickly spell check with
 rake proof
 ```
 
-Depending on your platform, words will be flagged that are correctly spelled (our baseline will be dictionaries-common on Ubuntu 12.04). So if you are 100% sure a word is correctly spelled then add it in all caps to ```dictionary.yml``` so it will not be flagged.
+Depending on your platform, words will be flagged that are correctly spelled (our baseline will be dictionaries-common on Ubuntu 14.04). So if you are 100% sure a word is correctly spelled then add it in all caps to ```dictionary.yml``` so it will not be flagged.
 
 To run the full test suite run
 

_config.yml

@@ -5,15 +5,22 @@ baseurl:
 google_analytics_key:
 show_full_navigation: true
 
+# Dependencies
+markdown:    kramdown
+kramdown:
+  input: GFM
+  hard_wrap: false
+highlighter: rouge
+
 # Values for the jekyll-seo-tag gem (https://github.com/jekyll/jekyll-seo-tag)
 logo: /siteicon.png
 description: Things we learned.
 author:
   name: ACM@UIUC
   email: til@acm.illinois.edu
-  twitter: ACM-UIUC# twitter username without the @ symbol
+  twitter: ACM-UIUC
 social:
-  name: ACM@UIUC TIL
+  name: ACM@UIUC 
   links:
     - https://github.com/acm-uiuc
 
@@ -34,7 +41,7 @@ exclude:
 
 collections:
   til:
-    title: Things We Learned
+    title: Today We Learned
     permalink: /:path/
     output: true
 

_layouts/default.html

@@ -43,17 +43,19 @@ <h1>
 					</li>
 				</ul>
 
-				<ul>
+				<ul class="article-list">
 					{% assign grouped = site.til | group_by: 'category' %}
 					{% for group in grouped %}
-						<li class="nav-item top-level {% if group.name == page.category %}current{% endif %}">
-							{% assign items = group.items | sort: 'order' %}
-							<a href="{{ site.baseurl }}{{ items.first.url }}">{{ group.name }}</a>
-							<ul>
-								{% for item in items %}
-									<li class="nav-item {% if item.url == page.url %}current{% endif %}"><a href="{{ site.baseurl }}{{ item.url }}">{{ item.title }}</a></li>
-								{% endfor %}
-							</ul>
+						<li>
+							<details>
+								{% assign items = group.items | sort: 'order' %}
+								<summary class="nav-item top-level {% if group.name == page.category %}current{% endif %}"><a>{{ group.name }}</a></summary>
+								<ul>
+									{% for item in items %}
+										<li class="nav-item {% if item.url == page.url %}current{% endif %}"><a href="{{ site.baseurl }}{{ item.url }}">{{ item.title }}</a></li>
+									{% endfor %}
+								</ul>
+							</details>
 						</li>
 					{% endfor %}
 				</ul>

_sass/_layout.scss

@@ -69,7 +69,8 @@ body {
 
 .main {
 	margin-top: $space + $nav-header-height;
-
+	height: 100vh;
+	overflow-y: scroll;
 	@media (min-width: $mobile-break) {
 		margin-top: 0;
 	}
@@ -117,6 +118,14 @@ header {
 		}
 	}
 
+	.article-list {
+		overflow-y: scroll;
+		height: calc(100vh - 195px);
+		height: -o-calc(100vh - 195px); /* opera */
+		height: -webkit-calc(100vh - 195px); /* google, safari */
+		height: -moz-calc(100vh - 195px); /* firefox */
+	}
+
 	.open-nav {
 		background-image: url(/images/menu.svg);
 		background-color: transparent;
@@ -246,7 +255,7 @@ nav > ul {
 		text-decoration: none;
 		font-size: 1.4rem;
 		padding: $space / 2 0 $space / 2 $space * 2;
-		display: block;
+		display: inline-block;
 	}
 
 	&.current > a,

_til/awk/awk-cookbook.md

@@ -0,0 +1,16 @@
+---
+title: Awk Cookbook
+category: awk
+---
+
+This is a collection of snipits of common tasks 
+
+#### Remove everything before the last space 
+```sh
+awk {'print $NF'}
+```
+
+#### Remove a substring from the end of each line in a file 
+```sh
+awk '{gsub(/{SUB_STRING]$/,""); print}' file.txt
+```

_til/git/checkout-previous-branch.md renamed to _til/git/branching/checkout-previous-branch.md

@@ -1,6 +1,6 @@
 ---
 title: Checkout Previous Branch
-category: git
+category: git/branching
 ---
 
 Git makes it easy to checkout the last branch you were on.

_til/git/clean-out-all-local-branches.md renamed to _til/git/branching/clean-out-all-local-branches.md

@@ -1,6 +1,6 @@
 ---
-title: Checkout Previous Branch
-category: git
+title: Clean Out All Local Branches
+category: git/branching
 ---
 
 Sometimes a project can get to a point where there are so many local

_til/git/grab-a-file-from-another-branch.md renamed to _til/git/branching/grab-a-file-from-another-branch.md

@@ -1,6 +1,6 @@
 ---
 title: Use a file from another branch
-category: git
+category: git/branching
 ---
 
 Sometimes you just need one file from another branch. Sure you could `git

_til/git/move-the-latest-commit-to-a-new-branch.md renamed to _til/git/branching/move-the-latest-commit-to-a-new-branch.md

@@ -1,6 +1,6 @@
 ---
 title: Move The Latest Commit To A New Branch
-category: git
+category: git/branching
 ---
 
 I sometimes find myself making a commit against the `master` branch that I

_til/git/renaming-a-branch.md renamed to _til/git/branching/renaming-a-branch.md

@@ -1,6 +1,6 @@
 ---
 title: Renaming A Branch 
-category: git
+category: git/branching
 ---
 
 The `-m` flag can be used with `git branch` to move/rename an existing

_til/git/viewing-a-file-on-another-branch.md renamed to _til/git/branching/viewing-a-file-on-another-branch.md

@@ -1,6 +1,6 @@
 ---
 title: Viewing A File On Another Branch
-category: git
+category: git/branching
 ---
 
 Sometimes you want to view a file on another branch (without switching

_til/git/what-is-the-current-branch.md renamed to _til/git/branching/what-is-the-current-branch.md

@@ -1,6 +1,6 @@
 ---
 title: What Is The Current Branch?
-category: git
+category: git/branching
 ---
 
 This question can be answered with one of git's plumbing commands,

_til/git/accessing-a-lost-commit.md renamed to _til/git/committing/accessing-a-lost-commit.md

@@ -1,6 +1,6 @@
 ---
 title: Accessing A Lost Commit
-category: git
+category: git/committing
 ---
 
 

_til/git/amend-author-of-previous-commit.md renamed to _til/git/committing/amend-author-of-previous-commit.md

@@ -1,6 +1,6 @@
 ---
 title: Amend Author Of Previous Commit
-category: git
+category: git/committing
 ---
 
 The author of the previous commit can be amended with the following command

_til/git/checking-commit-ancestry.md renamed to _til/git/committing/checking-commit-ancestry.md

@@ -1,6 +1,6 @@
 ---
 title: Checking Commit Ancestry
-category: git
+category: git/committing
 ---
 
 I have two commit shas and I want to know if the first is an ancestor of the

_til/git/cherry-pick-a-range-of-commits.md renamed to _til/git/committing/cherry-pick-a-range-of-commits.md

@@ -1,6 +1,6 @@
 ---
 title: Cherry Pick A Range Of Commits
-category: git
+category: git/committing
 ---
 
 Git's `cherry-pick` command allows you to specify a range of commits to be

_til/git/grep-over-commit-messages.md renamed to _til/git/committing/grep-over-commit-messages.md

@@ -1,6 +1,6 @@
 ---
 title: Grep Over Commit Messages 
-category: git
+category: git/committing
 ---
 
 

_til/git/list-different-commits-between-two-branches.md renamed to _til/git/committing/list-different-commits-between-two-branches.md

@@ -1,6 +1,6 @@
 ---
 title: List Different Commits Between Two Branches 
-category: git
+category: git/committing
 ---
 
 There are times when I want to get a sense of the difference between two

_til/git/show-all-commits-for-a-file-beyond-renaming.md renamed to _til/git/committing/show-all-commits-for-a-file-beyond-renaming.md

@@ -1,6 +1,6 @@
 ---
 title: Show All Commits For A File Beyond Renaming 
-category: git
+category: git/committing
 ---
 
 By including `-- <filename>` with a `git log` command, we can list all the

_til/git/split-up-a-commit.md renamed to _til/git/committing/split-up-a-commit.md

@@ -1,6 +1,6 @@
 ---
 title: Split Up a Commit, Rewrite History
-category: git
+category: git/committing
 ---
 
 When working on a branch with multiple commits, you can "go back in time" and revise previous commits any way you please.

_til/git/squashing-commits.md renamed to _til/git/committing/squashing-commits.md

@@ -1,6 +1,6 @@
 ---
 title: Two ways of squashing commits
-category: git
+category: git/committing
 ---
 
 It is handy to squash down your commits before merging your PR with

_til/git/verbose-commit-message.md renamed to _til/git/committing/verbose-commit-message.md

@@ -1,6 +1,6 @@
 ---
 title: Verbose Commit Message
-category: git
+category: git/committing
 ---
 
 Git allows you to display a *diff* of the staged changes in the commit

_til/git/find-the-initial-commit.md renamed to _til/git/history/find-the-initial-commit.md

@@ -1,6 +1,6 @@
 ---
 title: Find The Initial Commit
-category: git
+category: git/history
 ---
 
 By definition, the initial commit in a repository has no parents. You can

_til/git/last-commit-a-file-appeared-in.md renamed to _til/git/history/last-commit-a-file-appeared-in.md

@@ -1,6 +1,6 @@
 ---
 title: Last Commit A File Appeared In 
-category: git
+category: git/history
 ---
 
 In my project, I have a `README.md` file that I haven't modified in a while.

_til/git/reference-a-commit-via-commit-message-pattern-matching.md renamed to _til/git/history/reference-a-commit-via-commit-message-pattern-matching.md

@@ -1,6 +1,6 @@
 ---
 title: Reference A Commit Via Commit Message Pattern Matching 
-category: git
+category: git/history
 ---
 
 Generally when referencing a commit, you'll use the SHA or a portion of the

_til/git/intent-to-add.md renamed to _til/git/staging/intent-to-add.md

@@ -1,6 +1,6 @@
 ---
 title: Intent To Add 
-category: git
+category: git/staging
 ---
 
 Git commands like `git diff` and `git add --patch` are awesome, but their

_til/git/resetting-a-reset.md renamed to _til/git/staging/resetting-a-reset.md

@@ -1,6 +1,6 @@
 ---
 title: Resetting A Reset 
-category: git
+category: git/staging
 ---
 
 Sometimes we run commands like `git reset --hard HEAD~` when we shouldn't

_til/git/staging-and-commiting.md renamed to _til/git/staging/staging-and-commiting.md

@@ -1,6 +1,6 @@
 ---
 title: Staging and Committing
-category: git
+category: git/staging
 ---
 
 ## Staging 
@@ -53,4 +53,4 @@ or
 ```sh
 git commit -m --interactive "commit message"
 ```
-if you want to stage certain files 
+if you want to stage certain files 

_til/git/staging-stashes-interactively.md renamed to _til/git/staging/staging-stashes-interactively.md

@@ -1,6 +1,6 @@
 ---
 title: Staging Stashes Interactively
-category: git
+category: git/staging
 ---
 
 The `-p` flag can be used with `git stash`, just as it is used with `git add`,

_til/git/grab-a-single-file-from-a-stash.md renamed to _til/git/stashing/grab-a-single-file-from-a-stash.md

@@ -1,6 +1,6 @@
 ---
 title: Grab A Single File From A Stash
-category: git
+category: git/stashing
 ---
 
 In git, you can reference a commit SHA or branch to checkout differing

_til/git/stashing-only-unstaged-changes.md renamed to _til/git/stashing/stashing-only-unstaged-changes.md

@@ -1,6 +1,6 @@
 ---
 title: Stashing Only Unstaged Changes
-category: git
+category: git/stashing
 ---
 
 If you have both staged and unstaged changes in your project, you can

_til/git/stashing-untracked-files.md renamed to _til/git/stashing/stashing-untracked-files.md

@@ -1,6 +1,6 @@
 ---
 title: Stashing Untracked Files
-category: git
+category: git/stashing
 ---
 
 Normally when stashing changes, using `git stash`, git is only going to

_til/git/clean-up-old-remote-tracking-references.md renamed to _til/git/tracking/clean-up-old-remote-tracking-references.md

@@ -1,6 +1,6 @@
 ---
 title: Clean Up Old Remote Tracking References
-category: git
+category: git/tracking
 ---
 
 After working on a Git-versioned project for a while, you may find that

_til/git/delete-all-untracked-files.md renamed to _til/git/tracking/delete-all-untracked-files.md

@@ -1,6 +1,6 @@
 ---
 title:  Delete All Untracked Files
-category: git
+category: git/tracking
 ---
 
 Git provides a command explicitly intended for cleaning up (read: removing)

_til/git/excluding-files-locally.md renamed to _til/git/tracking/excluding-files-locally.md

@@ -1,6 +1,6 @@
 ---
 title: Excluding Files Locally
-category: git
+category: git/tracking
 ---
 
 Excluding (read: ignoring) files that should not be tracked is generally

_til/git/gitignore.md renamed to _til/git/tracking/gitignore.md

@@ -1,6 +1,6 @@
 ---
-title: Gitignore
-category: git
+title: .gitignore
+category: git/tracking
 ---
 
 Typically there are compiled files or very large generated files that you don't want tracked on remotes. So instead of being careful about what you do want to add and what you don't you can just use a gitignore to tell git what not to track. 

_til/git/ignore-changes-to-a-tracked-file.md renamed to _til/git/tracking/ignore-changes-to-a-tracked-file.md

@@ -1,6 +1,6 @@
 ---
 title: Ignore Changes To A Tracked File 
-category: git
+category: git/tracking
 ---
 
 Files that should never be tracked are listed in your `.gitignore` file. But