Copy column with file name as column header

Question

I wanted to organize my dataset by copying the a column from a number of text file and append the file name in the first row of the new files. Here is sample of my data

file1

a   a   b   b
1   2   3   4

file2

c   d   e   f
g   h   i   g

. . .

file3

11  12  23  12
2   4   6   7

filen

n1  n2  n3  n4
nn  nm  no  np

my desired output is to produce 4 data files by collecting respective columns from the datafile.

Output1

file1   file2   file3   filen
a   c   11  n1
1   g   2   nn

Output2

file1   file2   file3   filen
a   d   12  n2
2   h   4   nm

Output3

file1   file2   file3   filen
b   e   23  n3
3   i   6   no

Output4

file1   file2   file3   filen
b   f   12  n4
4   g   7   np

I was able to copy and organize in to the four desired files using

awk 'FNR==1{f++}{a[f,FNR]=$1}END{for(x=1;x<=FNR;x++){for(y=1;y<ARGC;y++)printf("%s ",a[y,x]);print ""}}' file* > output1
awk 'FNR==1{f++}{a[f,FNR]=$2}END{for(x=1;x<=FNR;x++){for(y=1;y<ARGC;y++)printf("%s ",a[y,x]);print ""}}' file* > output2
awk 'FNR==1{f++}{a[f,FNR]=$3}END{for(x=1;x<=FNR;x++){for(y=1;y<ARGC;y++)printf("%s ",a[y,x]);print ""}}' file* > output3
awk 'FNR==1{f++}{a[f,FNR]=$4}END{for(x=1;x<=FNR;x++){for(y=1;y<ARGC;y++)printf("%s ",a[y,x]);print ""}}' file* > output4

However, I couldn't append the file name in the first row of the output files.

Any help would be appreciated

Answer 1

If you already have the output files and just need to add a header with the file names to each of them, all you need is something like:

header=$(printf "%s %s %s %s\n" $(awk 'FNR==1{print FILENAME}' file*))
for file in output*; do 
    printf '%s\n%s\n' "$header" "$(cat $file)" > tmp && 
    mv tmp "$file"; 
done

Answer 2

Simply echo the file and then use the awk-processed data:

paste <( echo file1 ; awk '{print $1}' file1 )\
      <( echo file2 ; awk '{print $1}' file2 ) #and so on

The commands in parentheses get executed in their own subshells before being passed as input to paste

Answer 3

I would do the whole thing like this:
Use printf + cut to print the header, paste the files content and concatenate the two results then pipe that to awk and print every fourth column starting with the 1st one to output1, every fourth column starting with the 2nd one to output2 and so on:

for f in file*
do
printf " ${f}%.0s" 1 2 3 4
done | cut -c2- | cat - <(paste file*) | awk '{
for (i=1;i<=NF;i+=4){printf "%s ",$i >"output1"} ;print "" >"output1"
for (i=2;i<=NF;i+=4){printf "%s ",$i >"output2"} ;print "" >"output2"
for (i=3;i<=NF;i+=4){printf "%s ",$i >"output3"} ;print "" >"output3"
for (i=4;i<=NF;i+=4){printf "%s ",$i >"output4"} ;print "" >"output4"
}'