On Tuesday 06 July 2010 04:01:58, Anand Mitra wrote:
All the advice and help I got on my difficulties till now have been very useful. My current problem is a little weird and can't figure out what is happening.
I have been able to get the serialization working with DirTree based on the suggestions I have received till now. I have a function calcMD5 which given a FilePath will traverse the entire tree calculating the checksum of each file it encounters. The resultant structure is serializable by encode. But when I do a encodeFile to store the result to a file I get nothing.
,----
| *Main> calcMD5 "/tmp/tmp" | AncTree "/tmp" (DirW {name = "tmp", contents = [FileW {name = | "passwd",
file = Prop {md5sum = f54e7cef69973cecdce3c923da2f9222, modTime = Tue Jul 6 07:18:16 IST 2010, filenam = "/tmp/tmp/passwd"}}]})
| *Main> liftM encode $ calcMD5 "/tmp/tmp" | Chunk
"\NUL\NUL\NUL\NUL\NUL\NUL\NUL\EOT/tmp\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\ET Xtmp\NUL\NUL\NUL\NUL\NUL\NUL\NUL\SOH\SOH\NUL\NUL\NUL\NUL\NUL\NUL\NUL\ACKp asswd\NUL\245N|\239i\151<\236\220\227\201#\218/\146\"\NULL2\139`\NUL\NUL\ NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL\SI/tmp/tmp/passwd" Empty `----
clearly the encoding is working. But if I try to use encodeFile to write it to a file the file is not created.
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| *Main> liftM (encodeFile "/tmp/tmp-list") $ calcMD5 "/tmp/tmp"
calcMD5 :: IO something I suppose? then liftM (encodeFile "/tmp/tmp-list") $ calcMD5 "/tmp/tmp" has type IO (IO ()) and executing that only evaluates the action (encodeFile "/tmp/tmp-list" calcMD5Result) , it doesn't execute it. What you want is calcMD5 "/tmp/tmp" >>= encodeFile "/tmp/tmp-list"
| | $ ls /tmp/tmp-list | ls: cannot access /tmp/tmp-list: No such file or directory
`----
I tried a few other things like converting the Bytestring from encode into a string using show and then doing a writeFile on it. Unfortunately none of them worked.
regards