CODEWITHSUNDEEP
filebashcsvsed
lacrosse1991
lacrosse1991

Reputation: 3162

how can I use sed to replace blank fields in a csv file, with a string

I am currently working on a script which processes csv files, and I am trying to make the script replace all blank fields in the csv file, with a string "data_n/a". Initially I had thought I could simply use the following to accomplish this task:

sed -e "s/hi/data_n\/a/g"

but unfortunately that would leave out any empty fields that could possibly occur at the beginning or the end of the lines of the csv file. I am not sure how to go about this, so I was wondering if anyone could help push me in the right direction or offer advice as to what I should do? thanks!

also here is a sample of the csv file:

,,6004,,,15:00.00,30004,Colleen,2010-02-10
2,Closed,6005,,,30:00.00,30005,Rich,2010-02-11
7,Closed,6001,,,30:00.00,10001,Mary Beth,2010-02-11

Upvotes: 1

Views: 3159

Answers (4)

potong
potong

Reputation: 58371

This might work for you (GNU sed):

sed -r ':a;s/(^,)|(,)(,)|(,)$/\2\4data_n\/a\1\3/g;ta' file

Upvotes: 0

neevek
neevek

Reputation: 12138

If awk is an option, you can try the following:

awk -F, '{for(i=1;i<=NF;++i){if($i==""){printf "data_n/a"}else{printf $i} if(i<NF)printf ","} printf "\n"}' infile

Upvotes: 2

technosaurus
technosaurus

Reputation: 7802

the ^ indicates beginning of line and $ is end of the line

sed "s/,,/data_n\/a,/g;s/^,/data_n\/a,/;s/,$/,data_n\/a/" file >outfile

Upvotes: 0

Prince John Wesley
Prince John Wesley

Reputation: 63688

Using perl regex,

   perl -pe 's;^,|,$|(?<=,),;data_n\/a,;g' input.cvs

Using sed, 

$ sed -r 's;^,|,$;data_n\/a,;g
:l
s;,,;,data_n\/a,;g
t l' input.cvs

Upvotes: 3

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