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

I think I could have most of the oneliner goodness of h4sh, without having to do the module install, if I could figure out a way to include modules with ghc -e. or, alternatively some way to specify modules as a ghc flag, analogous to perl -MPath::To::Module -e 'commands' Can this be made to work? (From http://haskell.org/haskellwiki/Simple_unix_tools, which seems to be repeated somehow in h4sh, although I'm not completely certain on that.) *************************************** thartman@linodewhyou:~/learning/haskell/UnixTools$ echo "1234" | ghc -e 'interact id' 1234 thartman@linodewhyou:~/learning/haskell/UnixTools$ echo "1234" | ghc -e 'UnixTools.cat' <interactive>:1:0: Bad interface file: UnixTools.hi UnixTools.hi: openBinaryFile: does not exist (No such file or directory) thartman@linodewhyou:~/learning/haskell/UnixTools$ head -n23 UnixTools.hs module UnixTools where -- -- Some unix-like tools written in simple, clean Haskell -- -- import Data.List import Data.Char import System.IO import Text.Printf ..... -- The 'cat' program -- cat = interact id 2007/3/4, Donald Bruce Stewart :

Yes, it definitely is a little lagged. It should be ported to use lazy bytestrings too. I wsa more suggesting the one liners as examples of haskell use in the shell.

tphyahoo:

...

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

h4sh depends on hs-plugins.

And... **************** thartman@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@linodewhyou:~/haskellInstalls/hs-plugins$ **************** Advice?

2007/3/4, Donald Bruce Stewart :

...

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@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@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@linodewhyou:~/learning/haskell/UnixTools$

thartman@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 :

...

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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