[ale] OT: Bash Question

[Geoffrey]

I'm a ksh'er by nature, but threw this together.  I'm a stickler for 
saving processes, read that as fewer pipes.  Not a big deal these days, 
but it was on the 3b2 with 8 meg of memory.... :)

#!/bin/bash

# input file name is 'foo'

half_rec=$(($(wc -l < foo) / 2))

c=0
while read data && [ $((c=c+1)) -le $half_rec ]; do
         echo $c $data
done < foo


Asif wrote:
> The following works for me ( both for even,odd  and 0-numbered list in the list
> file )
> 
> #!/bin/bash
> 
> file=$1
> count=`wc -l $file | awk '{  printf "%i", $1/2 }'`
> i=0;
> for item in `cat $file`
> do
>         if [ $i -lt $count ]
>         then
>                 i=`expr $i + 1`
>                 echo $i $item
>         fi
> done
> 
> 
> Hope it helps.
> 
> Asif
> 
> Jeff Layton wrote:
> 
> 
>>Sorry about the OT, but I didn't know where else to turn.
>>
>>   I'm writing a simple shell script that cats a file to a
>>variable (the file is just a list). I want to loop over only
>>HALF of that list. So I want something like this:
>>
>>NODES=$(cat node.txt)
>>
>>for i in ${NODES}/2
>>do
>>   echo ${i}
>>done
>>
>>Of course, this doesn't work.
>>   I've also tried "counting" the number of items in the
>>list, dividing by 2, and using a while loop. The only thing
>>is, I don't know how to access a particular element in
>>the list,
>>
>>NODE_FILE="node.txt"
>>NODES=$(cat node.txt)
>>
>>declare -i NP
>>declare -i NP2
>>NP=`wc -l $NODES | awk '{print $1}'`
>>NP2=NP/2
>>
>>iloop=1
>>while (( $iloop <= ${NP2} ))
>>do
>>    # Here I want to echo the "iloop" element of $NODES
>>    let iloop+=1
>>done
>>
>>   I really appreciate any help anyone can give. I'm also
>>pretty tolerant of comments about my scripting capabilities :)
>>
>>Thanks!
>>
>>Jeff Layton
>>
>>---
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>>sent to listmaster at ale dot org.
>>
> 
> 
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> sent to listmaster at ale dot org.
> 
> 
> 


-- 
Until later: Geoffrey		esoteric at 3times25.net

I didn't have to buy my radio from a specific company to listen
to FM, why doesn't that apply to the Internet (anymore...)?


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