Having a little trouble with a bash shell script. Basically, I am inserting values into a file and then creating a variable from it and attempting to append and expand the variable values in another file via sed.
i.e:
cat animal.txt
Dog: 5
Ferret: 1
Cat: 10
Hamster: 2
NUM=$(cat animal.txt)
I want to then append the values from the variable 'NUM' to another file temp.txt:
cat temp.txt
country: England city: Manchester
country: England city: Hull
country: England city: Liverpool
country: England city: London
Tried all these variations but none suffice:
sed 's/$/'"${NUM}"'/' temp.txt
sed 's/$/"${NUM}"/' temp.txt
sed 's/$/'"${NUM}"'/' temp.txt
sed "s/$/"${NUM}"/" temp.txt
sed "s/$/\${NUM}\/" temp.txt
These two somewhat work but the variable is still never expanded:
sed 's/$/"${NUM}"/' temp.txt
sed 's/$/"\${NUM}\"/' temp.txt
country: England city: Manchester "${NUM}"
country: England city: Hull "${NUM}"
country: England city: Liverpool "${NUM}"
country: England city: London "${NUM}"
Even if I enclose the entire expression in double-quotes as such:
sed "s/$/${NUM}/" temp.txt
sed "s/$/\${NUM}\/" temp.txt
I get:
sed: -e expression #1, char 27: unterminated `s' command
sed: -e expression #1, char 12: unterminated `s' command
Desired Output:
country: England city: Manchester Dog: 5
country: England city: Hull Ferret: 1
country: England city: Liverpool Cat: 10
country: England city: London Hamster: 2
or
country: England city: Manchester Dog: 5
country: England city: Hull Ferret: 1
country: England city: Liverpool Cat: 10
country: England city: London Hamster: 2
I understand I should avoid single quotes and use double quotes but what am I missing? Is sed the wrong tool to work with here? and do you think awk would be better?
Thank you.
Is sed the wrong tool to work with here? Yes probably.
Anyway, if your animals.txt file is small enough, you could get away with this statement.
$ NUM="$(cat animal.txt)"; IFS=$'\n'; n=1; for num in $NUM; do i=0; while read -r line; do i=$((i + 1)); if [ $i -eq $n ]; then echo "$line" "$num"; n=$((n + 1)); break; fi; done < temp.txt; done
country: England city: Manchester Dog: 5
country: England city: Hull Ferret: 1
country: England city: Liverpool Cat: 10
country: England city: London Hamster: 2
But for large file size, awk is probably a better choice.
$ awk 'NR==FNR {num[FNR]=$0;next}{print $0 " " num[FNR]}' animal.txt temp.txt
country: England city: Manchester Dog: 5
country: England city: Hull Ferret: 1
country: England city: Liverpool Cat: 10
country: England city: London Hamster: 2