Unix file pattern issue: append changing value of variable pattern to copies of matching line - shell

Question

I have a file with contents:
abc|r=1,f=2,c=2
abc|r=1,f=2,c=2;r=3,f=4,c=8
I want a result like below:
abc|r=1,f=2,c=2|1
abc|r=1,f=2,c=2;r=3,f=4,c=8|1
abc|r=1,f=2,c=2;r=3,f=4,c=8|3
The third column value is r value. A new line would be inserted for each occurrence.
I have tried with:
for i in `cat $xxxx.txt`
do
#echo $i
live=$(echo $i | awk -F " " '{print $1}')
home=$(echo $i | awk -F " " '{print $2}')
echo $live
done
but is not working properly. I am a beginner to sed/awk and not sure how can I use them. Can someone please help on this?

Answer 1

awk to the rescue!
$ awk -F'[,;|]' '{c=0;
for(i=2;i<=NF;i++)
if(match($i,/^r=/)) a[c++]=substr($i,RSTART+2);
delim=substr($0,length($0))=="|"?"":"|";
for(i=0;i<c;i++) print $0 delim a[i]}' file
abc|r=1,f=2,c=2|1
abc|r=1,f=2,c=2;r=3,f=4,c=8|1
abc|r=1,f=2,c=2;r=3,f=4,c=8|3

Answer 2

Use an inner routine (made up of GNU grep, sed, and tr) to compile a second more elaborate sed command, the output of which needs further cleanup with more sed. Call the input file "foo".
sed -n $(grep -no 'r=[0-9]*' foo | \
sed 's/^[0-9]*/&s#.*#\&/;s/:r=/|/;s/.*/&#p;/' | \
tr -d '\n') foo | \
sed 's/|[0-9|]*|/|/'
Output:
abc|r=1,f=2,c=2|1
abc|r=1,f=2,c=2;r=3,f=4,c=8|1
abc|r=1,f=2,c=2;r=3,f=4,c=8|3
Looking at the inner sed code:
grep -no 'r=[0-9]*' foo | \
sed 's/^[0-9]*/&s#.*#\&/;s/:r=/|/;s/.*/&#p;/' | \
tr -d '\n'
It's purpose is to parse foo on-the-fly (when foo changes, so will the output), and in this instance come up with:
1s#.*#&|1#p;2s#.*#&|1#p;2s#.*#&|3#p;
Which is almost perfect, but it leaves in old data on the last line:
sed -n '1s#.*#&|1#p;2s#.*#&|1#p;2s#.*#&|3#p;' foo
abc|r=1,f=2,c=2|1
abc|r=1,f=2,c=2;r=3,f=4,c=8|1
abc|r=1,f=2,c=2;r=3,f=4,c=8|1|3
...which old data |1 is what the final sed 's/|[0-9|]*|/|/' removes.

Answer 3

Here is a pure bash solution. I wouldn't recommend actually using this, but it might help you understand better how to work with files in bash.
# Iterate over each line, splitting into three fields
# using | as the delimiter. (f3 is only there to make
# sure a trailing | is not included in the value of f2)
while IFS="|" read -r f1 f2 f3; do
# Create an array of variable groups from $f2, using ;
# as the delimiter
IFS=";" read -a groups <<< "$f2"
for group in "${groups[#]}"; do
# Get each variable from the group separately
# by splitting on ,
IFS=, read -a vars <<< "$group"
for var in "${vars[#]}"; do
# Split each assignment on =, create
# the variable for real, and quit once we
# have found r
IFS== read name value <<< "$var"
declare "$name=$value"
[[ $name == r ]] && break
done
# Output the desired line for the current value of r
printf '%s|%s|%s\n' "$f1" "$f2" "$r"
done
done < $xxxx.txt
Changes for ksh:
read -A instead of read -a.
typeset instead of declare.
If <<< is a problem, you can use a here document instead. For example:
IFS=";" read -A groups <<EOF
$f2
EOF