File Manipulation Loop - bash

Question

Ok, this question is two-fold: 1) The actual file manupulation bit 2) Looping this manipulation in unix
Part 1)
I have two files:
File_1
a b
c d
e f
g h
and File_2
A B
C D
E F
G H
I J
i would like to get (in the first instance) the following result:
a b
A B
>
c d
A B
>
e f
A B
>
g h
A B
...and save this output to outfile1.
I gather I would have to use things like awk, cut and/or paste but I can't manage to put it all together.
Part 2)
I then want to loop this manipulation for all rows in File_2 (note that the number of rows in File_1 is not the same as in File_2), such that I end up with 5 output files, where outfile2 would be:
a b
C D
>
c d
C D
>
e f
C D
>
g h
C D
and outfile3 would be:
a b
E F
>
c d
E F
>
e f
E F
>
g h
E F
etc.
At the moment I'm working in bash. Thank you in advance for any help!

Answer 1

This can be done with bash redirection:
i=1
while read f2; do
while read f1; do
echo "$f1"
echo "$f2"
echo ">"
done < File_1 | head -n -1 > output$i
(( i++ ))
done < File_2
head -n -1 avoids having a lone delimiter at the end of each output$i file.

Answer 2

to make outfile_3(with E F) for example:
x=$(sed -n '3p' File_2)
awk "{ printf \"%s\\n%s\\n>\\n\", \$0, \"$x\" }" File_1 > outfile_3
in first line '3p' cuts 3-rd line
Now let's do it in a loop:
(( i = 1 ))
while read line
do
awk "{ printf \"%s\\n%s\\n>\\n\", \$0, \"$line\" }" File_1 > "outfile_$i"
(( i++ ))
done < File_2

Answer 3

sort -m -f file1 file2 | uniq -i --all-repeated=separate
Looked rather close. However, on second reading I think you want something more like this perl script:
use strict;
use warnings;
open(my $FILE1, '<file1') or die;
my $output = 0;
while (my $a = <$FILE1>)
{
$output++;
open(my $OUT, ">output$output");
open(my $FILE2, '<file2') or die;
print $OUT "$a$_---\n" foreach (<$FILE2>);
close $FILE2;
close $OUT;
}
close $FILE1;
This creates output files output1, output12, output3, output..., as many as there are lines in file1

Answer 4

an awk one liner:
awk 'NR==FNR{a[NR]=$0;l=NR;next;} {b[FNR]=$0;}
END{f=1; for(x=1;x<=FNR;x++){for(i=1;i<=length(a);i++){
printf "%s\n%s\n%s\n", a[i],b[x],">" > "output"f }f++;}}' f1 f2
test:
kent$ head f1 f2
==> f1 <==
a b
c d
e f
g h
==> f2 <==
A B
C D
E F
G H
I J
kent$ awk 'NR==FNR{a[NR]=$0;l=NR;next;} {b[FNR]=$0;}
END{f=1; for(x=1;x<=FNR;x++){for(i=1;i<=length(a);i++){printf "%s\n%s\n%s\n", a[i],b[x],">" > "output"f }f++;}}' f1 f2
kent$ head -30 out*
==> output1 <==
a b
A B
>
c d
A B
>
e f
A B
>
g h
A B
>
==> output2 <==
a b
C D
>
c d
C D
>
e f
C D
>
g h
C D
>
==> output3 <==
a b
E F
>
c d
E F
>
e f
E F
>
g h
E F
>
==> output4 <==
a b
G H
>
c d
G H
>
e f
G H
>
g h
G H
>
==> output5 <==
a b
I J
>
c d
I J
>
e f
I J
>
g h
I J
>