10 ms·

Using Rust for 'Scripting'

185 points by deverton 10y ago

bajsejohannes 10y ago
I found myself doing the same just a few days ago when my local server suddenly had a new ip address. I made a simple script to scan IP addresses in the range: https://gist.github.com/johshoff/bed463ce8a122123e60bbc84bd1b1129 https://gist.github.com/johshoff/bed463ce8a122123e60bbc84bd1... There are probably faster ways, but none that I could think of a the time.
- pritambaral 10y ago
  > There are probably faster ways, but none that I could think of a the time For future reference, `nmap -p22 --open 192.168.1.*` does everything your rust script currently does. Nmap is THE tool for the job of network scans. IMO, it should be in the toolbelt of every techie that deals with any sort of computer network.
- brobinson 10y ago
  Cool program. Other quick ways besides the mentioned nmap: ping the broadcast address (if ICMP is allowed) or install avahi-daemon and you can just refer to "your-machines-hostname.local"
deleted 10y ago
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fnovd 10y ago
>Writing it in Rust means I can compile it and hand it to him, and he can run it. And that’s it. As wonderful as they are, the fact that languages like Python, Perl, Ruby, JavaScript, etc. require having the runtime bundled up with them makes just shipping a tool a lot harder—especially on systems which aren’t a Unix derivative and don’t have them installed by default. I'm wondering what part of the twelve step compilation process was found to be easier than simply installing Python on the target machine? Does the friend have any ability to audit the compiled binary before he runs it? Can he make a small change when he wants to re-use part of the solution?
- officialchicken 10y ago
  I agree. Instead the "friend" is taught the bad behavior of running untrusted (and I didn't see any tests, so untested and undocumented too) code in binary format on their machine. The glob-rename is exactly the sort of problem a script is supposed to solve easily. I feel the author justified the use of Rust and cross-compilation simply to avoid usage of a Windows OS (or VM) for such a trivial task. If the goal was to avoid installing additional run time/deps on the user's machine it seems that (#1) using powershell would have been the best option followed by (#2) a classic .cmd shell file as second best solution.
  - cgag 10y ago
    What? You mean like every other program they've ever run in their lives if they're not a developer, except developed by a personal friend? Compiling is easy. Configuring path variables and installing interpreters are arcane to non-developers.
  - yitchelle 10y ago
    > Instead the "friend" is taught the bad behavior of running untrusted (and I didn't see any tests, so untested and undocumented too) code in binary format on their machine. Being paranoid in the software you run on your machine is a double edge sword. How many people vet their software before using it, and how much vetting do you really need to do?
  - mathw 10y ago
    And as the author said, they don't know PowerShell or batch files very well. They also didn't pretend they had a strong justification for doing it. Rust was what they wanted to use, and hey look, Rust let them do it _and_ cross-compile it. I don't think there was an intention to say that everyone should do this instead of using shell scripts. It's not untrusted code, it's code that a friend wrote to help you out. That's not at all the same as installing random untrusted code off the internet. I write code to help out my friends with things they want to do - are you saying they shouldn't accept it from me just because they can't code themselves? I can give them the source code, but what good is that to them when they can't program and don't want to?
itsweller 10y ago
This reads less as “Python style scripting in Rust” and more as “I like Rust, also it’s cross-platform.” Not that this is a bad thing, but it feels like a bit of a far cry from my hacked together workflow of throw code in iPython and write out when I’m happy. I don’t see anything here that makes Rust any more attractive than whatever your multiplatform language of choice is for this use case scenario. That being said, the code is concise and readable, and the article was a short, pleasant read.
- ekidd 10y ago
  I've been using Rust to build a relatively large cross-platform command-line tool, and I've been genuinely impressed at how easy it is to get things to work on Windows. The Rust standard libraries Just Work on Windows, and they provide pathname handling, threads, environment variables, and a wealth of other tools. Many third party libraries will build for Windows without any problems as well. I actually do think that Rust's type system helps a bit, because it forces me to consider weird portability issues (such as the way Windows permits slightly invalid Unicode, which Rust represents as OSString instead of String). And of course, cross-compilation with MinGW is a real help. Sadly, OpenSSL still poses a fair number of portability issues, since it's notoriously difficult to link statically.
  - nenreme 10y ago
    > such as the way Windows permits slightly invalid Unicode Windows allows invalid UTF-16 while Unixes allow invalid UTF-8.
  - vvanders 10y ago
    Yup, as someone who's done x-platform C++(Windows/OSX/X360/PS3/etc) for a large part of my career the cross platform support is incredibly well done. Not having to deal with differences between MSVC, LLVM, GCC and other obscure toolchains is a blessing.
    - pjmlp 10y ago
      This is one reason why I enjoyed using Java so much in the early days, even without JIT. The differences between MSVC, LLVM, GCC are nothing to worry about, compared with the early days of C89 or C++ARM in the process of being standardized, coupled with different levels of POSIX support.
kibwen 10y ago
I admit, as a longtime Rust user I don't often get around to using Rust for scripting, probably because Python is available on all my personal machines and I'm so accustomed to it. But after reading this article I'm immensely impressed at how far Rust has come in the past few years WRT suitability for scripting, I really need to take a look at the glob and clap crates. Also, I'm very excited to hear that LLD is apparently usable for linking on Windows! It seems like we've been waiting for LLD since time immemorial. :)
evmar 10y ago
By the way, to solve the specific problem mentioned in the article, see "man 1 rename".
- saghm 10y ago
  Is this available on Windows? The author made it pretty clear the target user was on a Windows machine
  - k1t 10y ago
    The Windows rename command doesn't support recursively processing subfolders, but it can be achieved using one line of powershell: Get-ChildItem . -Recurse -Include *.cha | Rename-Item -NewName { $_.name -Replace '\.cha','.txt' }
    - flukus 10y ago
      From what I remember Include will only match items from the base directory and powershell gets stupidly complicated very quickly: http://flukus.github.io/2015/03/13/2015_03_13_Powershell-is-a-Joke/ http://flukus.github.io/2015/03/13/2015_03_13_Powershell-is-...
      - oblio 10y ago
        That compares Powershell to Nant. Nant tasks (inspired by Ant tasks) are more powerful than regular commands. Not even shell commands match those. He's comparing apples with an apple pie there.
        flukus 10y ago
        I started the article as a nant vs psake (PowerShell based build tool). Psake relies on PowerShell tools for things like copying files, which makes sense. I'm working on a similar one using make instead, which uses shell commands and it's a lot better than both.
    - 10y ago
deleted 10y ago
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ram_rar 10y ago
I personally like rust as a systems language. But the syntax really hurts my eyes as apposed to Python. A well crafted python code is soo easy to read. Rust can soo become very messy.
daholland 10y ago
There's also this handy cargo plugin that helps for using Rust for "scripting": https://github.com/DanielKeep/cargo-script https://github.com/DanielKeep/cargo-script It's especially handy for a one-file solution.
orcasauce 10y ago
Does Rust really support macOS, or did he mean to say OSX?
- Etzos 10y ago
  OS X was renamed to macOS, so they are the same thing as far as I know.
  - collyw 10y ago
    I remember macOS as the one before OS X. They changed it back again?
    - cpeterso 10y ago
      System → Mac OS → Mac OS X → OS X → macOS
    - pjmlp 10y ago
      Yes, this year when Sierra was launched.
  - deleted 10y ago
    [deleted]
denfromufa 10y ago
This guy has likely not prototyped in environment such as Jupyter notebooks or ptipython. It is not just language - there is whole ecosystem build around Python scripting: pandas, matplotlib, numpy, etc. And don't forget about debuggers and IDEs once your projects grow out of scripting environment. Did I mention hooking up to GUI or web app?
- the_duke 10y ago
  Which is all completely irrelevant for the task he had.
- chriskrycho 10y ago
  I've done a lot in those kinds of things, actually; they're awesome. I don't feel obliged to mention every possible alternative in every blog post; that would be absurdly tiring to do, and probably wouldn't add much value. (Edited so it didn't read as hostile as the original version of the comment did.)
brandur 10y ago
I love this idea. There's an implicit assumption that the reason scripting languages are suitable for scripts is that they play fast and loose with type systems, which allow enough shortcuts and escape hatches to be productive. But that's only part of the story. Along with typing, scripting languages also had the major advantage of being fast to bootstrap and run (`ruby script.rb`) and were fully "batteries included" with good standard libraries. These assumptions are certainly true, but they're much _more_ true when you're comparing them against "old world" languages like C, C++, or even Java. All of these require significant project scaffolding just to get running, and have varying levels of useful built-in utilities (C has almost nothing, C++ has the STL and maybe Boost if you're generous, and Java tried to have a useful core, but missed the mark in a number of places like HTTP). In the case of C and C++, complex build logic may also be required in the form of autoconf/automake/make. Newer compiled languages like Rust just don't have these issues anymore (I'd also include Go, Crystal, and some others in the list). Project scaffolding is built right into the language (Cargo) and the standard library is about as complete as you can get (and probably better than the classical scripting languages — all of Ruby/Python/Perl missed a good API for some things like HTTP, which led to the rise of separate packages like Faraday/Requests/etc). Anything that's not in the standard library is easily retrievable through great package managers that are bundled in with the core language. After you're over the initial learning curve of the language and standard library, it's possible to be nearly as productive in something like Rust as you can be in Python. As a bonus, you can also get reasonable reassurance that your program is correct before you run it — and even without writing an exhaustive test suite that exercises every line of code.
- cbsmith 10y ago
  So, I'm going to stop you right there on the fast to bootstrap & run... Certainly Java is kind of a hybrid worst if both worlds kind of thing, but C/C++? For simple scripting problems you don't need complex build logic. You can usually get by with "cc foo.c -o foo", which you can embed in the source file. Sure, if you have library dependencies it can be a bit more involved, but most modern IDE's (even less than modern) will manage that for you. It's particularly simple if you do static linking (which often makes sense with small scripts anyway). These days there are so many header only libraries that can remove even that boy if pain. On the deploy side, it's simple and likely faster to run than Rust. Now, many C/C++ projects start with auto tools/cmake or similar heavy lifting, and long build times. But there's selection bias there: those projects aren't simple scripting jobs, but actually intend to exploit close system integration and support building with a broad variety of compilers and linkers. They do it because they want people to use the code and for a larger project, it isn't that much extra overhead. Nah, the main pain with C++ in particular is the lack of a standard, simple library for network services like HTTP & databases. That problem seems to be finally getting resolved, but historically I've addressed by just standardizing on one of curl, cpp-http, etc. Once you do that with a modern C++17 compiler, and maybe their in Folly as well to make it truly easy, it starts to become a remarkably viable scripting language. You will type a bit more, but the compiler will also catch a lot more stuff for you automatically, reducing the cognitive load. There are better alternatives, but if you are in a shop with C++ already, the advantages of just using the same tool as everywhere else are more than enough to justify it.
gravypod 10y ago
This is over engineering if I've ever seen it. For one this is a single line bash script that would allow you to even handle drag and drop. Best user experience. Second, if you're going to over engineering just look for someone who has already done that for you: http://www.den4b.com/products/renamer http://www.den4b.com/products/renamer It's no use to engineer something that has been solved (unless you're learning) if there are already better solutions. Even if it is an example a better one should be used. The moral of the story should he use the best tool for the job, don't shoe horn a bad language for a into a solution, and also Google is usually the best tool for every job.
- kibwen 10y ago
  I don't think the author is really expecting people to go out and start uninstalling Python to do all their scripting in Rust. Seems to me like he saw this as an opportunity to show off the clap and glob crates, as well as write a little documentation for how to cross-compile Rust from Mac to Windows.
- Annatar 10y ago
  This is over engineering if I've ever seen it. Overcomplicating is more like it, for engineering implies a formal specification document which includes requirements, as well as documentation to go along with the product, not to mention complete integration with the target operating system substrate. This quickly hacked-together Rust program is light years away from that.
- IshKebab 10y ago
  I'm pretty sure the author was just practicing Rust. And although in this case using Bash would be fine, in most cases you shouldn't distribute Bash scripts. They're virtually always filled with bugs and they don't work on Windows.
- chriskrycho 10y ago
  1. Of course it's over-engineered. 2. It wouldn't be a bash script; it would have to be batch or PowerShell, neither of which I know well, and neither of which I like. 3. It was fun.
nurettin 10y ago
You could have done the same and given him a nice GUI in the process using lazarus. To install a cross-compiler on mac: $ fink install fpc-cross-i386-win32
mambodog 10y ago
> Add the dependencies... Nope. The beauty of a decent systems scripting language is that it includes everything you need (and ideally is already installed everywhere).
- kibwen 10y ago
  The author explains that the intended target is Windows, which has neither Perl nor Python (nor even Bash) installed by default, so "already installed everywhere" is already off the table. At that point, since Rust can produce static binaries, it doesn't matter what deps you pull in.
- sullyj3 10y ago
  Sure, but it's not that bad. Cargo is fantastic, once you have the dependencies in your manifest, `cargo build` downloads and compiles all your dependencies for you. It's pretty hassle free.
oconnor663 10y ago
For folks who want to do Bash-style shellouts and pipelines from Rust code, I'm working on a library to make it easier: https://github.com/oconnor663/duct.rs https://github.com/oconnor663/duct.rs
0xmohit 10y ago
One could also use Haskell [0] for scripting [1] using the turtle [2] library. turtle is a reimplementation of the Unix command line environment in Haskell so that you can use Haskell as both a shell and a scripting language. [0] https://www.haskell.org/ https://www.haskell.org/ [1] http://www.haskellforall.com/2015/01/use-haskell-for-shell-scripting.html http://www.haskellforall.com/2015/01/use-haskell-for-shell-s... [2] http://hackage.haskell.org/package/turtle http://hackage.haskell.org/package/turtle
- rtpg 10y ago
  If we're talking about alternatives, xonsh is also an excellent alternative (Python + subprocess mode) http://xon.sh/ http://xon.sh/
- chriskrycho 10y ago
  Big +1 to turtle, which is a really neat piece of software that manages both to be super useful on its own and to provide what looks like a really helpful way of learning Haskell.
Annatar 10y ago
The amount of contortions the author has had to go through is ridiculous, and all because the target operating system is Windows, and doesn't yet ship a production ripe UNIX userland (hence no AWK, sed, or zsh/tcsh/ksh out of the box). As a colleague of mine always says: give Wintendo no chance!
- mathw 10y ago
  Despite that, Windows is still the most popular desktop OS in the world by an enormous margin. You don't help a friend who needs to rename a load of files by saying "well, it'd be much easier if you first installed Linux". Or cygwin, or even the Windows Subsystem for Linux if they're running Windows 10 Anniversary Update.
  - Annatar 10y ago
    You help a friend by giving him a one liner COMMAND.COM shell script, instead of turning it into a cross-compiling hackfest just because you're a Rust fanboy (in author's own words).
    - ZoFreX 10y ago
      How is the one-liner shell script more helpful to the friend than the resulting binary? Yes it was convoluted but the point was the code author had to jump through hoops, not the end user.
      - Annatar 10y ago
        Then the code author should have jumped through the hoops to learn Windows shell scripting, instead of purposely overcomplicating. When I see things like these, it honestly makes me hate computers and IT.
        chriskrycho 10y ago
        No real hoops to jump; I'm sure I could have googled the batch script invocation for him easily. Again: the point was simply to use an interesting "hook" and then segue into providing resources on cross-compiling with a super-simple example.
jasoncchild 10y ago
This...felt misleading.
rshm 10y ago
I considered rust for daily scripts for the performance and statically compiled binary. But had to give up when the complexities from borrower checker came up and not to mention the limitation of libraries.
tigershark 10y ago
Was it too difficult to ask his friend to do right click -> create text document-> open it and write 'ren STAR.cha STAR.txt' -> save it as rename.bat and double click on it? Seriously, I'm not sure if this whole thing is a joke... edit: not sure why I cannot write the jolly character here
- nurettin 10y ago
  https://news.ycombinator.com/formatdoc https://news.ycombinator.com/formatdoc
- blub 10y ago
  This looks like an article on scripting, but it's in fact a subtle allegory about reinventing the wheel and overengineering. It's so subtle that even the author might have missed it.
- kbd 10y ago
  It looks like the rust script would rename files in the current directory and all subdirectories, whereas a batch rename would only work in the current directory.
- chriskrycho 10y ago
  It was an excuse to figure out the cross-compilation story with a tiny tool; he got his tool, I got my experience with a part of the Rust ecosystem I hadn't interacted with before. It was a win all around. (Note as well that I said explicitly that I asked if this was a "just give me a tool" or a "teach me something about scripting" kind of day!) :)
MayeulC 10y ago
While this can be seen as an interesting exercise, I can't help but feel that rust isn't the best tool here. First, there are a handful of existing tools, as other have pointed out (I would personally go for AntRenamer). Then, there are a few scripting languages already installed (admittedly maybe not the best or most well-known). A quick Google search would probably have given a result right away, since this is a pretty common scenario. Lastly, I am a bit curious, why go with msvc and not mingw/clang ?
- chriskrycho 10y ago
  For the "right tool for the problem", you're right; really, see up-thread where someone posted the one-liner. For MSVC over MinGW/Clang: part of my point here was to first learn and then document for the community how you do cross-compilation for MSVC. There are lots of projects out there where being able to link against MSVC is important, and it's also harder than linking against MinGW (which would have just been `rustup target add x86_64-pc-windows-gnu` and `cargo build --release --target=x86_64-pc-windows-gnu`, I believe; no extra linker stuff needed), so there's more value in documenting it and putting it out there for MSVC.
  - MayeulC 10y ago
    Thanks, I didn't realise that it was meant to be this way. To me, it sounded a bit like MSVC was the only option, and you had to install if for cross compiling. Since this is actually harder to do (from your own post), I worry a bit that a beginner might try to do it right away, to the risk of failing at it.
uros678 10y ago
One could probably get this done with one line of powershell code.
- notriddle 10y ago
  I would have, but I have a Windows box. Our OP has a Mac, so testing the script would be hard.
IshKebab 10y ago
Nice to see how good Rust is for 'scripting'. I think Go would have been a better choice from a purely technical point of view - it's easier to write, and has even easier setup and cross-compilation than Rust. But I guess part of the point of this was to practice Rust so fair enough!
pwdisswordfish 10y ago
Doesn't Windows have a built-in JavaScript runtime, the Windows Script Host? Sure, it may not be a very pretty language either, but it's still relatively sane compared to batch scripts. (I can't speak of PowerShell.)
- nurettin 10y ago
  I do like activex/js and wsh, but Wsh might require permissions to modify the filesystem, so installation/setup step can be harder than just copying and running a statically compiled executable.
  - pwdisswordfish 10y ago
    Last time I checked, doing new ActiveXObject("Scripting.FileSystemObject") did not require any extra 'permissions'.
    - nurettin 10y ago
      I remembered the problem, it was the execution of unsigned/remotely signed powershell scripts where you have to open powershell and give a permission[1] by typing something like: Set-ExecutionPolicy -ExecutionPolicy RemoteSigned [1] https://technet.microsoft.com/en-us/library/bb613481.aspx https://technet.microsoft.com/en-us/library/bb613481.aspx
StreamBright 10y ago
I think the author wanted to write "Using Rust instead of 'Scripting'". Perfectly makes sense. Nicer features, static types, compiled code, no runtime on the host system, etc. I prefer OCaml over Python,Bash etc for CLI apps, for the same reasons.
fold_left 10y ago
As someone who only very recently caught the Rust bug; seeing a reasonably small, familiar example like this is really helpful. Thanks for sharing. Maybe I can learn something by seeing if I can introduce threads/channels to the renaming part of the script as an exercise. For anyone else curious about Rust, my own learning spree was triggered after reading the "A very brief intro to Rust" Slide Deck [1] by Ashley Williams [2]. [1] https://ashleygwilliams.github.io/a-very-brief-intro-to-rust/#1 https://ashleygwilliams.github.io/a-very-brief-intro-to-rust... [2] https://twitter.com/ag_dubs https://twitter.com/ag_dubs
mobiuscog 10y ago
http://www.pyinstaller.org/ http://www.pyinstaller.org/ Single file executable. Job done. Of course, if you want to write something in Rust, it's not much use.
- chriskrycho 10y ago
  Oh, nice! PyInstaller didn't have Python 3 support the last time I looked at using it (mid-2015; I think it was in-work at that point), so I'm glad it's landed.
subtenante 10y ago
> As wonderful as they are, the fact that languages like Python, Perl, Ruby, JavaScript, etc. require having the runtime bundled up with them makes just shipping a tool a lot harder Not true for js on Windows, though. Windows runs JScript natively (same language as JavaScript, only a different name).
drej 10y ago
This topic is dear to me, I often deal with people without any software stacks on their machines and strict IT limits on installing new things. If I were on the same OS as the target user, I'd use pyinstaller. I've used it with very few issues over the past year on many projects. Most of them included Flask/Bottle and parts of numpy, it all worked like a charm. Cross compilation in Python is a bit of an issue, I for one have not resolved it in a satisfactory fashion (not saying it can't be done). If one wants to be closer to the metal, Go's cross compilation works out of the box, without all the LLVM/MSVC work that Rust requires (for now, that is). As long as you use the standard library (and packages dependent on the standard library), it will work right away. I've cross compiled Go from my Mac for Windows users when I couldn't get my Python setup to do so, worked perfectly. (Sure, you can script easy things as shown in other comments, this is a bit more general.)
- MereInterest 10y ago
  Re: Python, I've had success with running pyinstaller from within wine. I do most of my development from within linux, and so this covered my use case. No luck in cross-compiling into an OSX executable, though. Re: Go, I've had the opposite experience. So long as you only use pure-Go libraries, cross-compiling works. If you use any C libraries (which last time I checked, include some of the standard library), you run into issues. For me, it was OpenGL bindings that made cross-compiling impossible.
- scrubby 10y ago
  I've had great luck with Go as well. The cross compilation just works and the binary is easy to distribute.
- pcwalton 10y ago
  > If one wants to be closer to the metal, Go's cross compilation works out of the box, without all the LLVM/MSVC work that Rust requires (for now, that is). That's not "closer to the metal"; it's reinventing parts of the native toolchain.
  - drej 10y ago
blub 10y ago
There's lots of room for improvement here and I'm not sure Rust is the right tool for the job. First of all, why doesn't this have a UI? It would be much easier for the friend to select the folder with the .cha files and they could see a nice progress bar while they are renamed. However, if there are few files the renaming process would be too fast and the progress bar would flicker. An easy solution is to add sleep calls in the worker thread to ensure that the progress is visible. Of course the user could have lots of .cha files, and the friend might get bored. A popular pattern is to display an overview of the program features in picture + text format while a long procedure is running. There could be one about .cha file renaming for instance. It might make sense to also show ads, depending on the monetization strategy. Maybe the friend wants to buy something and they don't realise it yet. Finally, when the whole thing is done, the friend should be offered the option to post it on twitter and/or facebook. Something along the lines "I have just renamed 100 .cha files using rename-it. Try it yourself at <address>". The address needs to be different from the blog, probably an SPA, but I'm not an expert at that. And one more tip: don't ask for the facebook login before the renaming, this makes users suspicious. It's much better to ask before posting and explain why you need it. This builds trust. I said that Rust is not the right tool. I would maybe try Electron, it's also cross-platform, but the code can be reused on the back-end. For instance one can upload a zip of all their .cha files and they get a zip of txt files back. Ultimately desktop apps such as these are a thing of the past. But I guess it's a nice exercise.
dbattaglia 10y ago
It's a shame the author didn't frame this article differently by strictly focusing on how to cross compile a simple rust app on macOS and Windows. The focus on "scripting" seems to have really brought out the negativity in people here. I definitely learned something, I had no idea I could compile a Windows binary from my Mac.
- chriskrycho 10y ago
  The author here: I agree with your assessment. Apparently the scare quotes didn't convey my intent: it's easy to do something (including cross-platform) where I normally would have used a traditional scripting language, and the portability is nice. ¯\_(ツ)_/¯
  - dbattaglia 10y ago
    Well thanks anyway, I enjoyed it!
  - jsjohnst 10y ago
    I agree that it was very useful, despite the issue with the topic of choice. Thanks for writing it!
ghola2k5 10y ago
I know this isn't the point.. but I can't help myself... PowerShell: gci c:\somedir -r -filter "*.ext1" | %{Move-Item $_.FullName -Dest ($_.DirectoryName + "\" + $_.BaseName + ".ext2")}
GrumpyNl 10y ago
Its all about using the right tools / language for the job. And most of the solutions mentioned here are not the right tool for the job. Install python?? install this, install that. All the guy needs is a simple .exe file for windows that doesn't come with a manual howto install it.

185 points by deverton 10y ago

I found myself doing the same just a few days ago when my local server suddenly had a new ip address. I made a simple script to scan IP addresses in the range: https://gist.github.com/johshoff/bed463ce8a122123e60bbc84bd1b1129 https://gist.github.com/johshoff/bed463ce8a122123e60bbc84bd1... There are probably faster ways, but none that I could think of a the time.

pritambaral 10y ago
> There are probably faster ways, but none that I could think of a the time For future reference, `nmap -p22 --open 192.168.1.*` does everything your rust script currently does. Nmap is THE tool for the job of network scans. IMO, it should be in the toolbelt of every techie that deals with any sort of computer network.
brobinson 10y ago
Cool program. Other quick ways besides the mentioned nmap: ping the broadcast address (if ICMP is allowed) or install avahi-daemon and you can just refer to "your-machines-hostname.local"

deleted 10y ago

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fnovd 10y ago

>Writing it in Rust means I can compile it and hand it to him, and he can run it. And that’s it. As wonderful as they are, the fact that languages like Python, Perl, Ruby, JavaScript, etc. require having the runtime bundled up with them makes just shipping a tool a lot harder—especially on systems which aren’t a Unix derivative and don’t have them installed by default. I'm wondering what part of the twelve step compilation process was found to be easier than simply installing Python on the target machine? Does the friend have any ability to audit the compiled binary before he runs it? Can he make a small change when he wants to re-use part of the solution?

officialchicken 10y ago
I agree. Instead the "friend" is taught the bad behavior of running untrusted (and I didn't see any tests, so untested and undocumented too) code in binary format on their machine. The glob-rename is exactly the sort of problem a script is supposed to solve easily. I feel the author justified the use of Rust and cross-compilation simply to avoid usage of a Windows OS (or VM) for such a trivial task. If the goal was to avoid installing additional run time/deps on the user's machine it seems that (#1) using powershell would have been the best option followed by (#2) a classic .cmd shell file as second best solution.
- cgag 10y ago
  What? You mean like every other program they've ever run in their lives if they're not a developer, except developed by a personal friend? Compiling is easy. Configuring path variables and installing interpreters are arcane to non-developers.
- yitchelle 10y ago
  > Instead the "friend" is taught the bad behavior of running untrusted (and I didn't see any tests, so untested and undocumented too) code in binary format on their machine. Being paranoid in the software you run on your machine is a double edge sword. How many people vet their software before using it, and how much vetting do you really need to do?
- mathw 10y ago
  And as the author said, they don't know PowerShell or batch files very well. They also didn't pretend they had a strong justification for doing it. Rust was what they wanted to use, and hey look, Rust let them do it _and_ cross-compile it. I don't think there was an intention to say that everyone should do this instead of using shell scripts. It's not untrusted code, it's code that a friend wrote to help you out. That's not at all the same as installing random untrusted code off the internet. I write code to help out my friends with things they want to do - are you saying they shouldn't accept it from me just because they can't code themselves? I can give them the source code, but what good is that to them when they can't program and don't want to?

itsweller 10y ago

This reads less as “Python style scripting in Rust” and more as “I like Rust, also it’s cross-platform.” Not that this is a bad thing, but it feels like a bit of a far cry from my hacked together workflow of throw code in iPython and write out when I’m happy. I don’t see anything here that makes Rust any more attractive than whatever your multiplatform language of choice is for this use case scenario. That being said, the code is concise and readable, and the article was a short, pleasant read.

ekidd 10y ago
I've been using Rust to build a relatively large cross-platform command-line tool, and I've been genuinely impressed at how easy it is to get things to work on Windows. The Rust standard libraries Just Work on Windows, and they provide pathname handling, threads, environment variables, and a wealth of other tools. Many third party libraries will build for Windows without any problems as well. I actually do think that Rust's type system helps a bit, because it forces me to consider weird portability issues (such as the way Windows permits slightly invalid Unicode, which Rust represents as OSString instead of String). And of course, cross-compilation with MinGW is a real help. Sadly, OpenSSL still poses a fair number of portability issues, since it's notoriously difficult to link statically.
- nenreme 10y ago
  > such as the way Windows permits slightly invalid Unicode Windows allows invalid UTF-16 while Unixes allow invalid UTF-8.
- vvanders 10y ago
  Yup, as someone who's done x-platform C++(Windows/OSX/X360/PS3/etc) for a large part of my career the cross platform support is incredibly well done. Not having to deal with differences between MSVC, LLVM, GCC and other obscure toolchains is a blessing.
  - pjmlp 10y ago
    This is one reason why I enjoyed using Java so much in the early days, even without JIT. The differences between MSVC, LLVM, GCC are nothing to worry about, compared with the early days of C89 or C++ARM in the process of being standardized, coupled with different levels of POSIX support.

kibwen 10y ago

I admit, as a longtime Rust user I don't often get around to using Rust for scripting, probably because Python is available on all my personal machines and I'm so accustomed to it. But after reading this article I'm immensely impressed at how far Rust has come in the past few years WRT suitability for scripting, I really need to take a look at the glob and clap crates. Also, I'm very excited to hear that LLD is apparently usable for linking on Windows! It seems like we've been waiting for LLD since time immemorial. :)

evmar 10y ago

By the way, to solve the specific problem mentioned in the article, see "man 1 rename".

saghm 10y ago
Is this available on Windows? The author made it pretty clear the target user was on a Windows machine
- k1t 10y ago
  The Windows rename command doesn't support recursively processing subfolders, but it can be achieved using one line of powershell: Get-ChildItem . -Recurse -Include *.cha | Rename-Item -NewName { $_.name -Replace '\.cha','.txt' }
  - flukus 10y ago
    From what I remember Include will only match items from the base directory and powershell gets stupidly complicated very quickly: http://flukus.github.io/2015/03/13/2015_03_13_Powershell-is-a-Joke/ http://flukus.github.io/2015/03/13/2015_03_13_Powershell-is-...
    - oblio 10y ago
      That compares Powershell to Nant. Nant tasks (inspired by Ant tasks) are more powerful than regular commands. Not even shell commands match those. He's comparing apples with an apple pie there.
      - flukus 10y ago
        I started the article as a nant vs psake (PowerShell based build tool). Psake relies on PowerShell tools for things like copying files, which makes sense. I'm working on a similar one using make instead, which uses shell commands and it's a lot better than both.
  - 10y ago

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ram_rar 10y ago

I personally like rust as a systems language. But the syntax really hurts my eyes as apposed to Python. A well crafted python code is soo easy to read. Rust can soo become very messy.

daholland 10y ago

There's also this handy cargo plugin that helps for using Rust for "scripting": https://github.com/DanielKeep/cargo-script https://github.com/DanielKeep/cargo-script It's especially handy for a one-file solution.

orcasauce 10y ago

Does Rust really support macOS, or did he mean to say OSX?

Etzos 10y ago
OS X was renamed to macOS, so they are the same thing as far as I know.
- collyw 10y ago
  I remember macOS as the one before OS X. They changed it back again?
  - cpeterso 10y ago
    System → Mac OS → Mac OS X → OS X → macOS
  - pjmlp 10y ago
    Yes, this year when Sierra was launched.
- deleted 10y ago
  [deleted]

denfromufa 10y ago

This guy has likely not prototyped in environment such as Jupyter notebooks or ptipython. It is not just language - there is whole ecosystem build around Python scripting: pandas, matplotlib, numpy, etc. And don't forget about debuggers and IDEs once your projects grow out of scripting environment. Did I mention hooking up to GUI or web app?

the_duke 10y ago
Which is all completely irrelevant for the task he had.
chriskrycho 10y ago
I've done a lot in those kinds of things, actually; they're awesome. I don't feel obliged to mention every possible alternative in every blog post; that would be absurdly tiring to do, and probably wouldn't add much value. (Edited so it didn't read as hostile as the original version of the comment did.)

brandur 10y ago

I love this idea. There's an implicit assumption that the reason scripting languages are suitable for scripts is that they play fast and loose with type systems, which allow enough shortcuts and escape hatches to be productive. But that's only part of the story. Along with typing, scripting languages also had the major advantage of being fast to bootstrap and run (`ruby script.rb`) and were fully "batteries included" with good standard libraries. These assumptions are certainly true, but they're much _more_ true when you're comparing them against "old world" languages like C, C++, or even Java. All of these require significant project scaffolding just to get running, and have varying levels of useful built-in utilities (C has almost nothing, C++ has the STL and maybe Boost if you're generous, and Java tried to have a useful core, but missed the mark in a number of places like HTTP). In the case of C and C++, complex build logic may also be required in the form of autoconf/automake/make. Newer compiled languages like Rust just don't have these issues anymore (I'd also include Go, Crystal, and some others in the list). Project scaffolding is built right into the language (Cargo) and the standard library is about as complete as you can get (and probably better than the classical scripting languages — all of Ruby/Python/Perl missed a good API for some things like HTTP, which led to the rise of separate packages like Faraday/Requests/etc). Anything that's not in the standard library is easily retrievable through great package managers that are bundled in with the core language. After you're over the initial learning curve of the language and standard library, it's possible to be nearly as productive in something like Rust as you can be in Python. As a bonus, you can also get reasonable reassurance that your program is correct before you run it — and even without writing an exhaustive test suite that exercises every line of code.

cbsmith 10y ago
So, I'm going to stop you right there on the fast to bootstrap & run... Certainly Java is kind of a hybrid worst if both worlds kind of thing, but C/C++? For simple scripting problems you don't need complex build logic. You can usually get by with "cc foo.c -o foo", which you can embed in the source file. Sure, if you have library dependencies it can be a bit more involved, but most modern IDE's (even less than modern) will manage that for you. It's particularly simple if you do static linking (which often makes sense with small scripts anyway). These days there are so many header only libraries that can remove even that boy if pain. On the deploy side, it's simple and likely faster to run than Rust. Now, many C/C++ projects start with auto tools/cmake or similar heavy lifting, and long build times. But there's selection bias there: those projects aren't simple scripting jobs, but actually intend to exploit close system integration and support building with a broad variety of compilers and linkers. They do it because they want people to use the code and for a larger project, it isn't that much extra overhead. Nah, the main pain with C++ in particular is the lack of a standard, simple library for network services like HTTP & databases. That problem seems to be finally getting resolved, but historically I've addressed by just standardizing on one of curl, cpp-http, etc. Once you do that with a modern C++17 compiler, and maybe their in Folly as well to make it truly easy, it starts to become a remarkably viable scripting language. You will type a bit more, but the compiler will also catch a lot more stuff for you automatically, reducing the cognitive load. There are better alternatives, but if you are in a shop with C++ already, the advantages of just using the same tool as everywhere else are more than enough to justify it.

gravypod 10y ago

This is over engineering if I've ever seen it. For one this is a single line bash script that would allow you to even handle drag and drop. Best user experience. Second, if you're going to over engineering just look for someone who has already done that for you: http://www.den4b.com/products/renamer http://www.den4b.com/products/renamer It's no use to engineer something that has been solved (unless you're learning) if there are already better solutions. Even if it is an example a better one should be used. The moral of the story should he use the best tool for the job, don't shoe horn a bad language for a into a solution, and also Google is usually the best tool for every job.

kibwen 10y ago
I don't think the author is really expecting people to go out and start uninstalling Python to do all their scripting in Rust. Seems to me like he saw this as an opportunity to show off the clap and glob crates, as well as write a little documentation for how to cross-compile Rust from Mac to Windows.
Annatar 10y ago
This is over engineering if I've ever seen it. Overcomplicating is more like it, for engineering implies a formal specification document which includes requirements, as well as documentation to go along with the product, not to mention complete integration with the target operating system substrate. This quickly hacked-together Rust program is light years away from that.
IshKebab 10y ago
I'm pretty sure the author was just practicing Rust. And although in this case using Bash would be fine, in most cases you shouldn't distribute Bash scripts. They're virtually always filled with bugs and they don't work on Windows.
chriskrycho 10y ago
1. Of course it's over-engineered. 2. It wouldn't be a bash script; it would have to be batch or PowerShell, neither of which I know well, and neither of which I like. 3. It was fun.

nurettin 10y ago

You could have done the same and given him a nice GUI in the process using lazarus. To install a cross-compiler on mac: $ fink install fpc-cross-i386-win32

mambodog 10y ago

> Add the dependencies... Nope. The beauty of a decent systems scripting language is that it includes everything you need (and ideally is already installed everywhere).

kibwen 10y ago
The author explains that the intended target is Windows, which has neither Perl nor Python (nor even Bash) installed by default, so "already installed everywhere" is already off the table. At that point, since Rust can produce static binaries, it doesn't matter what deps you pull in.
sullyj3 10y ago
Sure, but it's not that bad. Cargo is fantastic, once you have the dependencies in your manifest, `cargo build` downloads and compiles all your dependencies for you. It's pretty hassle free.

oconnor663 10y ago

For folks who want to do Bash-style shellouts and pipelines from Rust code, I'm working on a library to make it easier: https://github.com/oconnor663/duct.rs https://github.com/oconnor663/duct.rs

0xmohit 10y ago

One could also use Haskell [0] for scripting [1] using the turtle [2] library. turtle is a reimplementation of the Unix command line environment in Haskell so that you can use Haskell as both a shell and a scripting language. [0] https://www.haskell.org/ https://www.haskell.org/ [1] http://www.haskellforall.com/2015/01/use-haskell-for-shell-scripting.html http://www.haskellforall.com/2015/01/use-haskell-for-shell-s... [2] http://hackage.haskell.org/package/turtle http://hackage.haskell.org/package/turtle

rtpg 10y ago
If we're talking about alternatives, xonsh is also an excellent alternative (Python + subprocess mode) http://xon.sh/ http://xon.sh/
chriskrycho 10y ago
Big +1 to turtle, which is a really neat piece of software that manages both to be super useful on its own and to provide what looks like a really helpful way of learning Haskell.

Annatar 10y ago

The amount of contortions the author has had to go through is ridiculous, and all because the target operating system is Windows, and doesn't yet ship a production ripe UNIX userland (hence no AWK, sed, or zsh/tcsh/ksh out of the box). As a colleague of mine always says: give Wintendo no chance!

mathw 10y ago
Despite that, Windows is still the most popular desktop OS in the world by an enormous margin. You don't help a friend who needs to rename a load of files by saying "well, it'd be much easier if you first installed Linux". Or cygwin, or even the Windows Subsystem for Linux if they're running Windows 10 Anniversary Update.
- Annatar 10y ago
  You help a friend by giving him a one liner COMMAND.COM shell script, instead of turning it into a cross-compiling hackfest just because you're a Rust fanboy (in author's own words).
  - ZoFreX 10y ago
    How is the one-liner shell script more helpful to the friend than the resulting binary? Yes it was convoluted but the point was the code author had to jump through hoops, not the end user.
    - Annatar 10y ago
      Then the code author should have jumped through the hoops to learn Windows shell scripting, instead of purposely overcomplicating. When I see things like these, it honestly makes me hate computers and IT.
      - chriskrycho 10y ago
        No real hoops to jump; I'm sure I could have googled the batch script invocation for him easily. Again: the point was simply to use an interesting "hook" and then segue into providing resources on cross-compiling with a super-simple example.

jasoncchild 10y ago

This...felt misleading.

rshm 10y ago

I considered rust for daily scripts for the performance and statically compiled binary. But had to give up when the complexities from borrower checker came up and not to mention the limitation of libraries.

tigershark 10y ago

Was it too difficult to ask his friend to do right click -> create text document-> open it and write 'ren STAR.cha STAR.txt' -> save it as rename.bat and double click on it? Seriously, I'm not sure if this whole thing is a joke... edit: not sure why I cannot write the jolly character here

nurettin 10y ago
https://news.ycombinator.com/formatdoc https://news.ycombinator.com/formatdoc
blub 10y ago
This looks like an article on scripting, but it's in fact a subtle allegory about reinventing the wheel and overengineering. It's so subtle that even the author might have missed it.
kbd 10y ago
It looks like the rust script would rename files in the current directory and all subdirectories, whereas a batch rename would only work in the current directory.
chriskrycho 10y ago
It was an excuse to figure out the cross-compilation story with a tiny tool; he got his tool, I got my experience with a part of the Rust ecosystem I hadn't interacted with before. It was a win all around. (Note as well that I said explicitly that I asked if this was a "just give me a tool" or a "teach me something about scripting" kind of day!) :)

MayeulC 10y ago

While this can be seen as an interesting exercise, I can't help but feel that rust isn't the best tool here. First, there are a handful of existing tools, as other have pointed out (I would personally go for AntRenamer). Then, there are a few scripting languages already installed (admittedly maybe not the best or most well-known). A quick Google search would probably have given a result right away, since this is a pretty common scenario. Lastly, I am a bit curious, why go with msvc and not mingw/clang ?

chriskrycho 10y ago
For the "right tool for the problem", you're right; really, see up-thread where someone posted the one-liner. For MSVC over MinGW/Clang: part of my point here was to first learn and then document for the community how you do cross-compilation for MSVC. There are lots of projects out there where being able to link against MSVC is important, and it's also harder than linking against MinGW (which would have just been `rustup target add x86_64-pc-windows-gnu` and `cargo build --release --target=x86_64-pc-windows-gnu`, I believe; no extra linker stuff needed), so there's more value in documenting it and putting it out there for MSVC.
- MayeulC 10y ago
  Thanks, I didn't realise that it was meant to be this way. To me, it sounded a bit like MSVC was the only option, and you had to install if for cross compiling. Since this is actually harder to do (from your own post), I worry a bit that a beginner might try to do it right away, to the risk of failing at it.

uros678 10y ago

One could probably get this done with one line of powershell code.

notriddle 10y ago
I would have, but I have a Windows box. Our OP has a Mac, so testing the script would be hard.

IshKebab 10y ago

Nice to see how good Rust is for 'scripting'. I think Go would have been a better choice from a purely technical point of view - it's easier to write, and has even easier setup and cross-compilation than Rust. But I guess part of the point of this was to practice Rust so fair enough!

pwdisswordfish 10y ago

Doesn't Windows have a built-in JavaScript runtime, the Windows Script Host? Sure, it may not be a very pretty language either, but it's still relatively sane compared to batch scripts. (I can't speak of PowerShell.)

nurettin 10y ago
I do like activex/js and wsh, but Wsh might require permissions to modify the filesystem, so installation/setup step can be harder than just copying and running a statically compiled executable.
- pwdisswordfish 10y ago
  Last time I checked, doing new ActiveXObject("Scripting.FileSystemObject") did not require any extra 'permissions'.
  - nurettin 10y ago
    I remembered the problem, it was the execution of unsigned/remotely signed powershell scripts where you have to open powershell and give a permission[1] by typing something like: Set-ExecutionPolicy -ExecutionPolicy RemoteSigned [1] https://technet.microsoft.com/en-us/library/bb613481.aspx https://technet.microsoft.com/en-us/library/bb613481.aspx

StreamBright 10y ago

I think the author wanted to write "Using Rust instead of 'Scripting'". Perfectly makes sense. Nicer features, static types, compiled code, no runtime on the host system, etc. I prefer OCaml over Python,Bash etc for CLI apps, for the same reasons.

fold_left 10y ago

As someone who only very recently caught the Rust bug; seeing a reasonably small, familiar example like this is really helpful. Thanks for sharing. Maybe I can learn something by seeing if I can introduce threads/channels to the renaming part of the script as an exercise. For anyone else curious about Rust, my own learning spree was triggered after reading the "A very brief intro to Rust" Slide Deck [1] by Ashley Williams [2]. [1] https://ashleygwilliams.github.io/a-very-brief-intro-to-rust/#1 https://ashleygwilliams.github.io/a-very-brief-intro-to-rust... [2] https://twitter.com/ag_dubs https://twitter.com/ag_dubs

mobiuscog 10y ago

http://www.pyinstaller.org/ http://www.pyinstaller.org/ Single file executable. Job done. Of course, if you want to write something in Rust, it's not much use.

chriskrycho 10y ago
Oh, nice! PyInstaller didn't have Python 3 support the last time I looked at using it (mid-2015; I think it was in-work at that point), so I'm glad it's landed.

subtenante 10y ago

> As wonderful as they are, the fact that languages like Python, Perl, Ruby, JavaScript, etc. require having the runtime bundled up with them makes just shipping a tool a lot harder Not true for js on Windows, though. Windows runs JScript natively (same language as JavaScript, only a different name).

drej 10y ago

This topic is dear to me, I often deal with people without any software stacks on their machines and strict IT limits on installing new things. If I were on the same OS as the target user, I'd use pyinstaller. I've used it with very few issues over the past year on many projects. Most of them included Flask/Bottle and parts of numpy, it all worked like a charm. Cross compilation in Python is a bit of an issue, I for one have not resolved it in a satisfactory fashion (not saying it can't be done). If one wants to be closer to the metal, Go's cross compilation works out of the box, without all the LLVM/MSVC work that Rust requires (for now, that is). As long as you use the standard library (and packages dependent on the standard library), it will work right away. I've cross compiled Go from my Mac for Windows users when I couldn't get my Python setup to do so, worked perfectly. (Sure, you can script easy things as shown in other comments, this is a bit more general.)

MereInterest 10y ago
Re: Python, I've had success with running pyinstaller from within wine. I do most of my development from within linux, and so this covered my use case. No luck in cross-compiling into an OSX executable, though. Re: Go, I've had the opposite experience. So long as you only use pure-Go libraries, cross-compiling works. If you use any C libraries (which last time I checked, include some of the standard library), you run into issues. For me, it was OpenGL bindings that made cross-compiling impossible.
scrubby 10y ago
I've had great luck with Go as well. The cross compilation just works and the binary is easy to distribute.
pcwalton 10y ago
> If one wants to be closer to the metal, Go's cross compilation works out of the box, without all the LLVM/MSVC work that Rust requires (for now, that is). That's not "closer to the metal"; it's reinventing parts of the native toolchain.
- drej 10y ago

blub 10y ago

There's lots of room for improvement here and I'm not sure Rust is the right tool for the job. First of all, why doesn't this have a UI? It would be much easier for the friend to select the folder with the .cha files and they could see a nice progress bar while they are renamed. However, if there are few files the renaming process would be too fast and the progress bar would flicker. An easy solution is to add sleep calls in the worker thread to ensure that the progress is visible. Of course the user could have lots of .cha files, and the friend might get bored. A popular pattern is to display an overview of the program features in picture + text format while a long procedure is running. There could be one about .cha file renaming for instance. It might make sense to also show ads, depending on the monetization strategy. Maybe the friend wants to buy something and they don't realise it yet. Finally, when the whole thing is done, the friend should be offered the option to post it on twitter and/or facebook. Something along the lines "I have just renamed 100 .cha files using rename-it. Try it yourself at <address>". The address needs to be different from the blog, probably an SPA, but I'm not an expert at that. And one more tip: don't ask for the facebook login before the renaming, this makes users suspicious. It's much better to ask before posting and explain why you need it. This builds trust. I said that Rust is not the right tool. I would maybe try Electron, it's also cross-platform, but the code can be reused on the back-end. For instance one can upload a zip of all their .cha files and they get a zip of txt files back. Ultimately desktop apps such as these are a thing of the past. But I guess it's a nice exercise.

dbattaglia 10y ago

It's a shame the author didn't frame this article differently by strictly focusing on how to cross compile a simple rust app on macOS and Windows. The focus on "scripting" seems to have really brought out the negativity in people here. I definitely learned something, I had no idea I could compile a Windows binary from my Mac.

chriskrycho 10y ago
The author here: I agree with your assessment. Apparently the scare quotes didn't convey my intent: it's easy to do something (including cross-platform) where I normally would have used a traditional scripting language, and the portability is nice. ¯\_(ツ)_/¯
- dbattaglia 10y ago
  Well thanks anyway, I enjoyed it!
- jsjohnst 10y ago
  I agree that it was very useful, despite the issue with the topic of choice. Thanks for writing it!

ghola2k5 10y ago

I know this isn't the point.. but I can't help myself... PowerShell: gci c:\somedir -r -filter "*.ext1" | %{Move-Item $_.FullName -Dest ($_.DirectoryName + "\" + $_.BaseName + ".ext2")}

GrumpyNl 10y ago

Its all about using the right tools / language for the job. And most of the solutions mentioned here are not the right tool for the job. Install python?? install this, install that. All the guy needs is a simple .exe file for windows that doesn't come with a manual howto install it.