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* @dev OpcodeChecker processes contract code to generate a bitmap of used opcodes.
* DO NOT USE: See the vulnerability identified by Recmo below. A patch will be provided soon.
* The generated bitmap can be used to enforce whitelisting and blacklisting on contract code.
* Bit n of the bitmap is set iff opcode n is used. For instance, the presence of the STOP opcode
* will result in bit 0 of the bitmap being set.
* A best-effort attempt is made to skip over unreachable data, but there may be false positives.
hanula / two_letter_domains.txt
Created February 23, 2015 16:31
2 letter domains
iansheridan /
Created March 15, 2011 14:25
A cheat sheet for GIT


git clone <repo>

clone the repository specified by ; this is similar to "checkout" in some other version control systems such as Subversion and CVS

Add colors to your ~/.gitconfig file:


There are so many great GIFs out there and I want to have copies of them. Twitter makes that harder than it should be by converting them to MP4 and not providing access to the source material. To make it easier, I made a bash pipeline that takes a tweet URL and a filename, extracts the MP4 from that tweet and uses ffmpeg to convert back to GIF.


  • ffmpeg
    • macOS: brew install ffmpeg
    • Ubuntu/Debian: apt install ffmpeg
This file has been truncated, but you can view the full file.
spalladino /
Last active May 20, 2024 21:04
Falsehoods that Ethereum programmers believe

Falsehoods that Ethereum programmers believe

I recently stumbled upon Falsehoods programmers believe about time zones, which got a good laugh out of me. It reminded me of other great lists of falsehoods, such as about names or time, and made me look for an equivalent for Ethereum. Having found none, here is my humble contribution to this set.

About Gas

Calling estimateGas will return the gas required by my transaction

Calling estimateGas will return the gas that your transaction would require if it were mined now. The current state of the chain may be very different to the state in which your tx will get mined. So when your tx i

jbgo /
Last active May 23, 2024 12:29
How to recover a git branch you accidentally deleted

UPDATE: A better way! (August 2015)

As pointed out by @johntyree in the comments, using git reflog is easier and more reliable. Thanks for the suggestion!

 $ git reflog
1ed7510 HEAD@{1}: checkout: moving from develop to 1ed7510
3970d09 HEAD@{2}: checkout: moving from b-fix-build to develop
1ed7510 HEAD@{3}: commit: got everything working the way I want
70b3696 HEAD@{4}: commit: upgrade rails, do some refactoring
tbrianjones / free_email_provider_domains.txt
Last active July 8, 2024 00:56
A list of free email provider domains. Some of these are probably not around anymore. I've combined a dozen lists from around the web. Current "major providers" should all be in here as of the date this is created.
MohamedAlaa / tmux-cheatsheet.markdown
Last active July 13, 2024 14:35
tmux shortcuts & cheatsheet

tmux shortcuts & cheatsheet

start new:


start new with session name:

tmux new -s myname