Inserting multiple files into a template - linux

Question

I have a template file and need to insert data from multiple files into this file. The template (template.txt) is laid out like so:
Title
Data 1
Data 2
Data 3
I need to put each data set under its title. So say the data files are:
Data1.dat Data2.dat Data3.dat
1 2 3 0 0 0 500 300 100
4 5 6 0 0 0 400 200 000
The final product needs to be:
Title
Data 1
1 2 3
4 5 6
Data 2
0 0 0
0 0 0
Data 3
500 300 100
400 200 000
How can I make this possible? I can insert one data set into the template using:
sed '/Data 1/r Data1.dat' template.txt
I want to be able to do it for as many data files as needed and can't figure out how to automate it.

Answer 1

this would do...
while read -r line;
do
file=$(echo $line | sed 's/ //;s/$/.dat/');
echo $line;
if [ -f "$file" ]; then cat "$file"; fi;
done < template.txt

Answer 2

There's a lot of details left out of your post that could affect this, but given what you've asked, this seems to work assuming each line is the exact filename with spaces removed and missing the .dat extension, and that all files exist.
$ cat template.txt
Title
Data 1
Data 2
Data 3
$ awk 'NR==1{print;next;}{print;filename=$0;gsub(" ","",filename);system("cat "filename".dat");}' template.txt
Title
Data 1
1 2 3
4 5 6
Data 2
0 0 0
0 0 0
Data 3
500 300 100
400 200 000
NR==1{print;next;} emits the first line and then goes to the next.
{print;filename=$0".dat";gsub(" ","",filename);system("cat "filename");}
for all other lines, print the line, assign it to a var and append .dat, then replace spaces and make a system call to cat that file.
Another example:
$ awk 'NR==1{print;next;}{print;filename=$0".dat";gsub(" ","",filename);system("cat "filename);}' template.txt
Title
Data 1
1 2 3
4 5 6
Data 2
0 0 0
0 0 0
Data 3
500 300 100
400 200 000
Data 4
4-1 4-2 4-3
4-1 4-2 4-3
4-1 4-2 4-3
Data 5
5-1 5-2 5-3
5-1 5-2 5-3
5-1 5-2 5-3
Data 6
6-1 6-2 6-3
6-1 6-2 6-3
6-1 6-2 6-3
Data 7
7-1 7-2 7-3
7-1 7-2 7-3
7-1 7-2 7-3

Answer 3

$ cat tst.awk
NR==FNR {
if ( FNR==1 ) {
print
}
else {
filename = $0 ".dat"
gsub(/[[:space:]]/,"",filename)
title[filename] = $0
ARGV[ARGC] = filename
ARGC++
}
next
}
FNR==1 { print title[FILENAME] }
{ print }
$ awk -f tst.awk template.txt
Title
Data 1
1 2 3
4 5 6
Data 2
0 0 0
0 0 0
Data 3
500 300 100
400 200 000