Script - OP_PUSHDATAs

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Enter a script to debug in the following textarea. The script is automatically parsed and executed. The step-by-step execution status (incl. stack status) will be shown.

Notice that there are some restriction (some of them are inherited from the backend library, Bitcore):

Hex data should be prefixed by "0x". Hex data to be pushed onto the stack should be prefixed by the number of bytes to be pushed (e.g. "4 0x01020304") or OP_PUSHDATA? should be used (e.g. "OP_PUSHDATA1 4 0x01020304"). Signature checks such as OP_CHECKSIG and OP_CHECKMULTISIG are not supported (yet).

Users not being familiar with Bitcoin's script language should refer to this article at Bitcoin Wiki.

Tha sample code shown by default is "transaction puzzle" described at Bitcoin Wiki. The first 80byte pushdata is the hex-encoded block header of the genesis block and the second to last push data is the doulbe-SHA256 hash of it, namely the block hash (reversed block ID) of the genesis...

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This module implements an interpreter for the Bitcoin Script language. The link points to a good documentation and I will just mention the main charateristics of this language. For more details, refer to the link.

Bitcoin script is a stack based primary arithmetic language. There are operators to push data to the stack and to perform operations on the elements of the stack. The stack is made of arbitrary long binary strings. When used for math operations, these byte strings are considered little endian big integers.

The language has IF/THEN/ELSE but no loops. It is therefore non Turing complete and program execution time is bounded. Besides the classic operators, it has cryptographic functions such as hashing operators and signature verification.

When a transaction produces Outputs, they mention a value and a script. The later is similar to a program split in two. To spend the output, one must provide the other half of the program so that the full program...

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[[tx_script_ops]] [appendix] == Transaction Script Language Operators, Constants, and Symbols ((("Script language", id="ix_appdx-scriptops-asciidoc0", range="startofrange")))((("Script language","reserved operator codes", id="ix_appdx-scriptops-asciidoc1", range="startofrange")))> shows operators for pushing values onto the stack.((("Script language","push operators"))) [[tx_script_ops_table_pushdata]] .Push value onto stack [options="header"] |======= | Symbol | Value (hex) | Description | OP_0 or OP_FALSE | 0x00 | An empty array is pushed onto the stack | 1-75 | 0x01-0x4b | Push the next N bytes onto the stack, where N is 1 to 75 bytes | OP_PUSHDATA1 | 0x4c | The next script byte contains N, push the following N bytes onto the stack | OP_PUSHDATA2 | 0x4d | The next two script bytes contain N, push the following N bytes onto the stack | OP_PUSHDATA4 | 0x4e | The next four script bytes contain N, push the following N bytes onto the stack | OP_1NEGATE | 0x4f | Push the value "–1"...

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Bitcoin uses a scripting system for transactions. Forth-like, Script is simple, stack-based, and processed from left to right. It is purposefully not Turing-complete, with no loops.

A script is essentially a list of instructions recorded with each transaction that describe how the next person wanting to spend the Bitcoins being transferred can gain access to them. The script for a typical Bitcoin transfer to destination Bitcoin address D simply encumbers future spending of the bitcoins with two things: the spender must provide

a public key that, when hashed, yields destination address D embedded in the script, and a signature to show evidence of the private key corresponding to the public key just provided.

Scripting provides the flexibility to change the parameters of what's needed to spend transferred Bitcoins. For example, the scripting system could be used to require two private keys, or a combination of several, or even no keys at all.

A transaction is...

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See on Github

Script is a simple scripting language, as well as the core of Bitcoin transaction processing. If you ever wrote assembly code you’ll find this article very easy to understand –probably entertaining–, otherwise it might well be one of the most challenging. Keep focused!

Meet machine code

A script is a computer program, and as a programmer you certainly know what a program is. A program takes an input, executes for some time, then returns an output. Programming languages are our tool to write programs that computers will understand, because most languages come with compilers that map human-friendly code to CPU operations, also known as opcodes.

Opcodes

Opcodes include memory manipulation, math, loops, function calls and everything you find in procedural programming languages like C. They make up the spoken language of a CPU, the so-called machine code. Since bytes are computers’ preferred idiom, no wonder opcodes are bytes...

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en Standards, we agree, are important, but they should not become an unnecessary obstacle to the early resolution of the future status of Kosovo

ru Мы согласны, что стандарты имеют весьма важное значение, однако они не должны становится ненужным препятствием на пути к скорейшему урегулированию вопроса о будущем статусе Косово

en Mapping: identifying services, service providers and legal or regulatory frameworks that are or need to be in place to prevent and respond to violence, abuse, exploitation and unnecessary separation from family

ru Картограммы, в которых указываются услуги, поставщики услуг и нормативная или правовая база, обеспечивающие или обязанные обеспечивать защиту и реагировать на случаи насилия, жестокого обращения, эксплуатации и необоснованного разлучения с семьей

en • Industry should help to avoid the development of unnecessary or excessive regulation; instead every effort should be made to facilitate the effective enforcement of...

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The Bitcoin network was subject to a strange attack this week. Up to 25% of the recorded transactions were modified using a technique called

transaction malleability

. By examining the Bitcoin blockchain, I've created an hour-by-hour look at the attack.

For details on how transaction malleability works, see my article Bitcoin transaction malleability: looking at the bytes. As a quick summary, the attacker takes a new Bitcoin transaction, modifies it in a trivial way that changes the transaction hash, and sends it back into the Bitcoin system. The modified transaction functions exactly the same (transferring the bitcoins between the same addresses), but results in two slightly different versions of the transaction in the system. However, if client software or exchange software depends on the transaction hash, temporarily having two different hashes for the transaction can cause a variety of problems.

The reason malleability is possible is that inside a Bitcoin...

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P2SH “relaxed standards” for P2SH redeem scripts in Bitcoin Core 0.10.0

What is meant by "relaxed standards" for P2SH redeem scripts in Bitcoin Core 0.10.0?

I just try to create redeem script with OP_PUSHDATA1 opcode and push it using Blockchain.info

RAW TX is

In case I start use OP_PUSHDATA1 transaction not broadcast to network At example Blockchain.info give me error "P2SH script execution resulted in a non-true stack"

Transaction with data = 90 bytes

...
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All bitcoin transactions have scripts embedded into its inputs and outputs. The scripts use a very simple programming language, which is evaluated from left to right using a stack. The language is designed such that it guarantees all scripts will execute in a limited amount of time (it is not Turing-Complete).

When a transaction is validated, the input scripts are concatenated with the output scripts and evaluated. To be valid, all transaction scripts must evaluate to true. A good analogy for how this works is that the output scripts are puzzles that specify in which conditions can those bitcoins be spent. The input scripts provide the correct data to make those output scripts evaluate to true.

For more detailed information about the bitcoin scripting language, check the online reference on bitcoin's wiki.

The Script object provides an interface to construct, parse, and identify bitcoin scripts. It also gives simple interfaces to create most common script...

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FEATURESWorks on other spreadsheets in the SAME FOLDER that you want to establish push relationships between.Auto-discovers source and destination spreadsheets based on file name. This makes systems built with pushData easy to copy and share using a folder-copying utility.Auto-discovers all headers in source and destination sheets.Allows user to specify which headers to push, in any order, from source sheet to destination sheet.Syncs each source with its destination on a time trigger of a user-specified number of hours between runs, making it more stable and reliable than IMPORTRANGE function for large data sets.USE CASESCreate a master student roster for your school and create any number of student tracking systems based off the master roster by pushing things like student ID, name, email, etc. to each tracking sheet.

Join the Apps Script for Edu...

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