Capturing the values of column in one parameter

Shell Programming and Scripting
1

Hi,

I am trying to capture the values of a column in a parameter..here is what I wanted to do...

1,2,3,4
2,3,4,1
3,4,1,2
4,1,2,3

is there any way that I could get the values of column values into one parameter??

Here is what I want...
COL1=1,2,3,4
COL2=2,3,4,1
COL3=3,4,1,2
COL4=,4,1,2,3

I am just taking an example of 1234 and original file will not have same values in both rows and columns....

Is it possible??

Thanks,

2

Hi,

I think firstly your query is not clear ...
Pls specify that u have one coulmn or multiple column seperated by comma

If its the first case then ...ie only one column then here's the solution

put yr inputs in a file called file1

for var in `cat file1`
do
kvar=`echo $var`
......
.....
.....
done

where ..... symbolize what operation u want to do with var ie kvar ie 1,2,3,4

thks

Aparna

3

Thanks aparna,

I may have not stated it correctly but this is what I want, I have a file where I have values seperated by a comma and have 4 rows and 4 columns (4x4 matrix)
cat file1
a,b,c,d
e,f,g,h
i,j,k,l
m,n,o,p

all I want is...parameters
COL1=a,e,i,m
COL2=b,f,j,n
COL3=c,g,k,o
COL4=d,h,l,p

any suggestions here...?

4

This might help

#! /bin/bash
row=""
row4=""
row3=""
row2=""
count=0

while read line; do

row=${row}`echo ${line%%,}` # extracts first character from the string
row4=${row4}`echo ${line##,}`# extracts last character

echo $line > temp # saves read line to a temporary file
row2=${row2}`awk -F"," '{ print $2 }' temp` # extracts second character
row3=${row3}`awk -F"," '{ print $3 }' temp` # extracts third character

count=`expr $count + 1` # Adds the ","

if [ $count -lt 4 ]; then
row=${row}","
row2=${row2}","
row3=${row3}","
row4=${row4}","
fi
done<$1 # Read data from file
rm -f filez # Removes the old output file if it exists

# Add all the rows to the new output file.
echo $row >> filez
echo $row2 >> filez
echo $row3 >> filez
echo $row4 >> filez

rm -f temp # delete the temporary file

echo "Contents of the new File:" # display the contents of the output file
cat filez

May not be the best solution possible but it works

5

the following code will give u the first row (ie a,e,i,m)

gawk -F ',' 'BEGIN {col=""}{ col=col $1 "," ; }END {print substr ( col,1,length ( col ) -1 ) }' file1

change '$1' as '$2' to get second row & '$3' to get third row.

6

$ cat filex
a,b,c,d
e,f,g,h
i,j,k,l
m,n,o,p

#Using his logic, it can be done in 1 line as

$ awk -F "," 'BEGIN { col="";col2="";col3="";col4="" }{col=col $1; col2=col2 $2; col3=col3 $3; col4=col4 $4 }END { print col"\n"col2"\n"col3"\n"col4 }' filex > filez
# It might seem complex at first but infact is a simple assignment and reassignment of variables and then printing them out to the desired file.

$ cat filez
aeim
bfjn
cgko
dhlp

Thanks prajith, I learnt something new about awk. :slight_smile: