4 ms·

I don't think anyone would seriously advocate using awk for complex projects these days, but the idea of keeping data really close to the OS/shell is a very pow

• dpritchett 13y ago
  I shamelessly reach for the backtick shell notation in any exploratory Ruby code that needs it. I try to replace it with something written in Ruby if the codebase grows beyond my laptop, but backticks never get old. => 1.upto(100) { |n| puts `curl -s fizzy.heroku.com/#{n}` } 1 2 Fizz 4 Buzz ...
  • manish_gill 13y ago
    Ha! That backtick is the only reason most of my "scripts" are being written in Ruby instead of Python. :)
    • sauravc 13y ago
      Seems pretty easy in python: from subprocess import call call(["ls", "-l"]) or import os os.system("ls -l")
      • deleted 13y ago
        [deleted]
      • tomsthumb 13y ago
        While there are several ways to skin that cat, the suggested way is to use subprocess.Popen . Also, when using Popen, calling .wait() can cause problems if you are expecting large amounts of info back from stdin or stderr. Using .communicate() is generally better.
        • bra-ket 13y ago
          this. python has too many ways to skin the cat.
          • tomsthumb 13y ago
            hehe, while I do agree in this particular situation, it's rather funny to see that in writing.
      • shawabawa3 13y ago
        The difference between "pretty easy" and "easy" changes everything. Compare from subprocess import call call(["ls", "-l"]) to `ls -l`
        • bashinator 13y ago
          I really like the python sh library for stuff like this. Would you rather do what you wrote, or this? for listing in ls('-l'): '''etc''' Here's the library in question - https://pypi.python.org/pypi/pbs https://pypi.python.org/pypi/pbs - it makes me super happy to do shell work in python.
          • CatMtKing 13y ago
            Wow, that's a neat library. You can just import any program and use it like a function (from sh import grep)! Thanks for the link. Also, sh documentation: http://amoffat.github.io/sh/ http://amoffat.github.io/sh/
            • mkarttic 13y ago
              i use Sh to interface with my cmus player. from sh import cmus_remote! :)
            • bashinator 13y ago
              Yeah, it's replaced just a ton of boilerplate `def run(*args):` functions wrapping Popen. I couldn't be happier.
• cturner 13y ago
  What would you put forward as an alternative to awk for the kinds of complex projects the author describes? Sam and vi are both descendants of ed, but go in very different directions. Is there a path forward from awk that focuses on different strengths to perl's choices? (perhaps avoiding perl's move to being multi-paradigm) Is there something that sits close to unix in the way awk does, but which is stronger?
  • silentbicycle 13y ago
    I use lua for that, and it seems to be a very good fit. There's awk influence in its history, so it's probably no accident.
  • JulianMorrison 13y ago
    Hadoop and friends.
  • UNIXgod 13y ago
    Ruby does awk for the most part. I can't comment on strength since awk has a small footprint compared to both ruby and perl clocking in just under 96k. Also both emacs and ed are descendants of TECO =) The editors have had major impact on our languages mainly because regular expressions, called regular sets at the time, where implemented in Thompson's ed which was based on an earlier line editor implementation called qed used on ctss and multics. One can follow the evolution almost in dialect fairly well. ed -> grep -> sed -> awk ed -> em -> ex -> vi awk -> perl -> ruby so ed -> grep -> sed -> awk -> perl -> ruby The right tool for the right job when all you know is a chainsaw everything looks like a hammer unix process are cheap and all that yada yada philosophical paradigmy finite state automata pipelines vs pointers vs classes vs recursive enumeration iterative parenthesis backtick mind expansions expression logic =P
    • smalltalk 13y ago
      ed is not a descendant of TECO. http://web.mit.edu/kolya/misc/txt/editors http://web.mit.edu/kolya/misc/txt/editors
• voyvf 13y ago
  > I don't think anyone would seriously advocate using awk for complex projects these days, Never underestimate the power of intellectual inertia, and the lengths people will go to in order to continue using their favorite tool - no matter how poorly suited to a task it might be. ):
• stcredzero 13y ago
  > Take Python, which is supposedly a "scripting" language, but requires relatively painful amounts of boilerplate to actually read from or write to pipes, etc. It's a shame Scheme Shell didn't catch on more. That had a syntax for pipes that simply used the pipe symbol in a way that feels a lot like just using pipes in bash. Unforunately, the project page is down, and the Wikipedia entry doesn't have the best examples. http://en.wikipedia.org/wiki/Scsh http://en.wikipedia.org/wiki/Scsh
• sprayk 13y ago
  It has always pretty easy for me to read from and write to pipes in python, assuming you are talking about /std(out|in|err)/. from sys import stdin, stdout, stderr for n,line in enumerate(stdin): stdout.write(str(n) + '\n') stderr.write(line) Is that the kind of reading and writing you are talking about?
  • jjoonathan 13y ago
    I suspect it has more to do with stringing together the inputs/outputs of multiple programs, which is outright painful in python. The syntax is terribly verbose (import subprocess, use subprocess.call, refer to a few enum values in the subprocess package, wire them together which requires a line of code rather than a character). Worse, pipes are tricky to implement correctly. It's easy to deadlock the python process by overflowing a pipe's buffer (wait for exit to read the buffer, buffer fills before subprocess exit, deadlock), so people who don't have an intimate knowledge of the underlying implementation will find themselves stuck with a bug they can't fix. Compare this to a shell where the combination of &&, ||, and | can fit on a single line what would have taken dozens of lines of python.
    • abraininavat 13y ago
      See https://github.com/kennethreitz/envoy https://github.com/kennethreitz/envoy Example: >> r = envoy.run('uptime | pbcopy')
    • sprayk 13y ago
      Ah, so using python for stuff bash is usually used for. I thought OP meant writing python scripts to be used as components of bash scripts. For _that_ type of python, I usually use the sh module[0]. It handles piping pretty well, especially if you use StringIO to deal with the pipes. Unfortunately, return code-based conditionals are nowhere as simple as || and && are in shell. [0] http://amoffat.github.io/sh/ http://amoffat.github.io/sh/
• bcoates 13y ago
  > I don't think anyone would seriously advocate using awk for complex projects these days I guess it depends what you mean by 'complex'. Doing basic statistical summaries on a few columns of a TB or so of some logfile in a weird format would be a big project using a lot of the tools I've had to use, but it's more or less 'hello world' for awk. I really like it as part of an "ETL before you ETL" process where you massage your data into a format that makes your official ETL tool with fancy capabilities not choke. The simplicity of awk also gives it a cultural advantage over things like perl in that you can argue that you're not really introducing another language into your environment, just including some glue logic with a Standardized Tool Everyone Should Know. The only thing I'm familiar with that does such a good job of keeping simple things simple even when distributed or at largish data volumes is Splunk.
  • tieTYT 13y ago
    What is Splunk? Are you talking about this: http://en.wikipedia.org/wiki/Splunk http://en.wikipedia.org/wiki/Splunk
• sampo 13y ago
  One of the first video lectures in Coursera's Machine Learning course, Andrew Ng gives a pretty similar explanation why he chose Octave as the language for the course; in his experience, students get more done in Octave than in any other language he has tried teaching with.