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filtering input from read command

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# 1  
Old 07-13-2011
filtering input from read command
I need help understanding a script I'm modifying which someone else has written. Basically I’m looping through a buffer that holds records fetched from a database query. I need a way to separate the primary key values from other attributes in the result. Heres the code:
Code:
BUFF=buffer_file
[query results] > $BUFF
{
   while read row
   do
       rowID= $(row#*|)   #??
       rowCol=$(row%*|)        #??
   done
} < $BUFF

Last edited by d3mon_spawn; 07-13-2011 at 05:24 PM..
# 2  
Old 07-13-2011
I think the last > is probably supposed to be a <.

this table of string operations explains what those mean among many more, assuming you're using a bourne or ksh shell.

Assuming the number of columns is always the same, there's probably a better way to do this too.
# 3  
Old 07-13-2011
I agree
# 4  
Old 07-14-2011
Is the number of columns always the same, though? Hard to offer suggestions when I don't know what the input and output is supposed to be.
# 5  
Old 07-14-2011
Sorry for not specifying. I'm using bourne and yes the collumns are always the same (only two). Output from the query would look something like this:
1 server001
2 server002
3 server003

---------- Post updated at 12:47 PM ---------- Previous update was at 12:45 PM ----------

I seem to have found a solution that has been working but may not be the best immplementation:
Code:
rowID=$(echo $row | awk '{print $1}')
rowCol=$(echo $row | awk '{print $2}')

# 6  
Old 07-14-2011
Easy peasy. read does this all by itself.
Code:
while read rowID rowCol
do
        echo "rowID=$rowID rowCol=$rowCol"
done < filename

If the separator was | instead of whitespace you'd just do
Code:
while IFS="|" read rowID rowCol
do
        echo "rowID=$rowID rowCol=$rowCol"
done < filename

This builtin is hundreds of times faster than calling awk for individual lines.
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