I need to create multiple file having content like this below and substitute value for this from other different 3 files.
name:
url:
description:
I tried to add values to the above content using while loop but it executed with 3^3 combination ,actually what i need is that to create a file with first line of the 3 files substituted and second file with 2nd line of the 3 files substituted and so on.
This is the code i used.
while read line1;
do
while read line2;
do
while read line3;
do
echo "
name: $line1
url: $line2
description: $line3
" > $line1.txt ;
done < url.txt
done < description.txt
done < name.txt
In a nested loop, each loop will process the whole file in one go, resulting in out-of-sync output.
Instead you need to read the 3 files in a single while loop, using extra file descriptors to process the other files:
while read name && read description <&3 && read url <&4; do
echo "
name: $name
url: $url
description: $description
" > $name.txt
done < name.txt 3< description.txt 4< url.txt
Assuming the files name.txt, url.txt, and description.txt have the same number of lines, this task could be done using paste and sed utilities:
paste -d '\n' name.txt url.txt description.txt |
sed 'N;N;s/\(.*\n\)\(.*\n\)/name: \1url: \2description: /'
or, if files are not too large, an alternative bash solution could be:
#!/bin/bash
mapfile names < name.txt
mapfile urls < url.txt
mapfile descs < description.txt
for ((i = 0; i < ${#names[@]}; ++i)); do
printf 'name: %surl: %sdescription: %s' \
"${names[i]}" "${urls[i]}" "${descs[i]}"
done