How to modify specific column using sed or awk based on specific pattern

Question

I have a csv file looks like this:

c1,c2,c3,http://aaa.com/blblbblb\nhttp://bbb.com/sdsdsds\nhttp://ccc.com\nhttp://foo.com/ghghghgh

cc1,cc2,cc3,http://eee.com/blblbblb\nhttp://foo.com/sdsdsds\nhttp://fff.com\nhttp://ttt.com/ghghghgh

ccc1,ccc2,ccc3,http://foo.com/blblbblb\nhttp://vvv.com/sdsdsds\nhttp://foo.com/nmnmnmnm\nhttp://qqq.com\nhttp://kkk.com/ghghghgh

is it possible manipulate above csv file and export as follows: (using sed or awk or similar bash commands)

c1,c2,c3,http://foo.com/ghghghgh 

cc1,cc2,cc3,http://foo.com/sdsdsds

ccc1,ccc2,ccc3,http://foo.com/blblbblb;http://foo.com/nmnmnmnm

Actually i want to manipulate only 4th column and Remain http://foo.com/{some string} pattern (in other words, extract links from 4th column when contain foo.com domain)

Answer 1

sed '
    s|http://foo.com|@|g #replace `foo.com` domain with rare symbol
    /./s/\\n\|$/;/g      #replace `\n` by `;`  and add it to end 
    s/http[^@]*;//g      #remove all domain(s) without `foo.com`
    s|@|http://foo.com|g #place `foo.com` back
    s/;$//               #remove `;` from the end of line
    ' csv.file

Answer 2

You can do the following:

cat your_csv.csv | sed 's/\\n/,/g' | cut -d ',' -f 4

sed will change all the \ns to , and cut chooses the 4th field when the delimiter is ,