[Haskell-cafe] Re: wanted: haskell one-liners (in the perl sense of one-liners)

[Thomas Hartman]

That seems like a really great thing to have. But I had troubles installing it.

h4sh depends on hs-plugins.

And...
****************
thartman at linodewhyou:~/haskellInstalls/hs-plugins$ ./Setup.lhs configure
Setup.lhs: Warning: The field "hs-source-dir" is deprecated, please
use hs-source-dirs.
Configuring plugins-1.0...
configure: /usr/local/bin/ghc-pkg
configure: Dependency base-any: using base-2.0
configure: Dependency Cabal-any: using Cabal-1.1.6
Setup.lhs: cannot satisfy dependency haskell-src-any
thartman at linodewhyou:~/haskellInstalls/hs-plugins$
****************
Advice?

2007/3/4, Donald Bruce Stewart <dons at cse.unsw.edu.au>:
> There's some nice one liners bundled with h4sh:
>
>     http://www.cse.unsw.edu.au/~dons/h4sh.html
>
> For example:
>
>     http://www.cse.unsw.edu.au/~dons/h4sh.txt
>
> If you recall, h4sh is a set of unix wrappers to the list library.
> I still use them everyday, though probably should put out a new release
> soon.
>
> -- Don
>
>
> tphyahoo:
> > To answer my original question, here's a few ways to accomplish what I
> > wanted with haskell
> >
> > Perl is still a lot faster than ghc -e, but I guess if you wanted
> > speed you could compile first.
> >
> > ********************************************************************
> >
> > thartman at linodewhyou:~/learning/haskell/UnixTools$ ls -l
> > total 16
> > -rw-r--r-- 1 thartman thartman 2726 Dec 20 07:56 UnixTools.hs
> > -rw-r--r-- 1 thartman thartman   82 Jan  7 07:18 echo.hs
> > -rwxr--r-- 1 thartman thartman  790 Mar  4 05:02 oneliners.sh
> > -rwxr--r-- 1 thartman thartman  646 Mar  4 04:18 oneliners.sh~
> >
> > thartman at linodewhyou:~/learning/haskell/UnixTools$ ./oneliners.sh
> > haskell, ghc -e pipe
> > 16
> >
> > real    0m1.652s
> > user    0m0.600s
> > sys     0m0.030s
> > **********
> > haskell, hmap pipe
> > 16
> >
> > real    0m1.549s
> > user    0m0.410s
> > sys     0m0.200s
> > **********
> > haskell, two pipes
> > 16
> >
> > real    0m2.153s
> > user    0m0.900s
> > sys     0m0.370s
> > **********
> > perl, two pipes
> > 16
> >
> > real    0m0.185s
> > user    0m0.010s
> > sys     0m0.100s
> >
> > thartman at linodewhyou:~/learning/haskell/UnixTools$
> >
> >
> > thartman at linodewhyou:~/learning/haskell/UnixTools$ cat oneliners.sh
> > hmap (){ ghc -e "interact ($*)";  }
> > hmapl (){ hmap  "unlines.($*).lines" ; }
> > hmapw (){ hmapl "map (unwords.($*).words)" ; }
> >
> > function filesizes () {
> >  find -maxdepth 1 -type f | xargs du
> > }
> >
> > echo haskell, ghc -e pipe
> > time filesizes | ghc -e 'interact $ (++"\n") . show . sum . map ( (
> > read :: String -> Integer ) . head . words ) . lines '
> > echo "**********"
> >
> > echo haskell, hmap pipe
> > time filesizes | hmap '(++"\n") . show . sum . map ( ( read :: String
> > -> Integer ) . head . words ) . lines'
> > echo "**********"
> >
> > echo haskell, two pipes
> > time filesizes | hmapl "map ( head . words )" | hmap '(++"\n") . show
> > . sum . map ( read :: String -> Integer ) . lines'
> > echo "**********"
> >
> > echo perl, two pipes
> > time filesizes | perl -ane 'print "$F[0]\n"' | perl -e '$sum += $_
> > while <>; print "$sum\n"'
> >
> >
> > 2007/3/2, Thomas Hartman <tphyahoo at gmail.com>:
> > >Okay, I am aware of
> > >
> > >http://haskell.org/haskellwiki/Simple_unix_tools
> > >
> > >which gives some implementation of simple unix utilities in haskell.
> > >
> > >But I couldn't figure out how to use them directly from the shell, and
> > >of course that's what most readers will probably wnat.
> > >
> > >Or let me put it another way.
> > >
> > >Is there a way to do
> > >
> > >  find -maxdepth 1 -type f | xargs du | perl -ane 'print "\$F[0]\n"' |
> > >perl -e '$sum += $_ while <>; print "$sum\n"'
> > >
> > >as a shell command that idiomatically uses haskell?
> > >
> > >For non-perlers, that sums up the disk usage of all files in the
> > >current directory, skipping subdirs.
> > >
> > >print "\$F[0]\n
> > >
> > >looks at the first (space delimited) collumn of output.
> > >
> > >perl -e '$sum += $_ while <>; print "$sum\n"'
> > >
> > >, which is I guess the meat of the program, sums up all the numbers
> > >spewed out of the first column, so in the end you get a total.
> > >
> > >So, anyone out there want to establish a haskell one liner tradition?
> > >
> > >:)
> > >
> > >thomas.
> > >
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