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Pick a random word from a file UNIX

Posted on 2007-11-22
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Last Modified: 2008-02-01
nice easy question for u smart lot how do u pick a random word from a file that is in the formart of

word1
word2
word3
word4
word5
?
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Question by:DSwiftie
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by:Dozer42
ID: 20337004
perl -e 'open IN, "<FILENAME";rand($.) < 1 && ($n=$_) while <IN>;print $n'
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by:Tintin
ID: 20337030
#!/usr/bin/bash
file=/path/to/file
lines=`wc -l <$file
n=$RANDOM
let "n %= $lines"
sed -n ${n}p $file
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by:ozo
ID: 20337096
perl -ne '$n=$_ if rand $.<1;END{print $n}' filename
perl -MTie::File -le 'tie @a,"Tie::File", "filename"; print @a[rand @a]'
awk 'rand<1/NR{n=$0}END{print n}' < filename
perl -e '@a=<>;print$a[rand@a]' filename


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by:DSwiftie
ID: 20338073
i know using sed or perlor awk is well worth knowin but tryn to avoid using those tools
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by:ozo
ID: 20338100
What tools would you prefer to use?
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Accepted Solution

by:
ozo earned 125 total points
ID: 20338159
#!/usr/bin/bash
count=0
while read line ;  do  
 if [[  $(( RANDOM % ++count )) = 0 ]] ; then p=$line ; fi
done < filename
echo $p
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Author Comment

by:DSwiftie
ID: 20340910
ozo thanx again m8 allways spot on. Thankyou all for the help well apriaciated
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by:Tintin
ID: 20341956
On large files, ozo's solution will be *much* slower than my bash solution.
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by:ozo
ID: 20342316
It's slower by about the same factor on small files too.

But there seemed to be an inexplicable desire to avoid sed.
We could have used head|tail instead, but  I didn't know if those were to be avoided too.
We could have implemented the sed function in pure bash, which would have simplified the while loop slightly, but that could still leave the wc
reimplementing wc in pure bash could mean two loops, and it seemed simpler to do it in one
even if there is a performance penalty, which might depend on the implementation.


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Author Comment

by:DSwiftie
ID: 20343619
i can't explain sed thats y i dont use it doing tutorial on using sed and awk now but for now can't xplain myself when using it so am tryin to keep everything at a level i can understand.
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