extracting a row from a file using shell script

Question

I have a CSV file, with the columns like below,

User     Name   Env   Role
user1    pap    dev    dev
user2    nic    uat    test

I need to extract a row, with respect to either the column 'Env' or 'User'. The script 'extract.sh' I have written is,

k=$2
field=$3
head -1 $1; cat $1 | awk -F "," -v k=`echo $k` -v field=`echo $field` '{ k=k;j=$field; if ( j==k )  print $0}'

The script is called with 3 parameters like this , sh extract.sh username.csv dev 3 the first parameter is csv file the second is the value and the third is column no, the output i am getting is

User Name Env Role
user1 pap dev  dev

But I need the output like this,

User = user1 
Name = pap
Env = dev
Role = dev

Could anyone please help me in getting this ?

You're doing too much work assigning the awk variables: -v k="$k" -v field="$field" — glenn jackman
– glenn jackman, Commented May 7, 2015 at 11:02

anubhava · Accepted Answer · 2015-05-08 10:00:53Z

3

You can use this awk:

awk -F, -v RS='\r\n' -v col=$3 -v val="$2" 'NR==1 {for (i=1; i<=NF; i++) hdr[i]=$i;next}
             $col == val {for (i=1; i<=NF; i++) print hdr[i], "=", $i; exit}' "$1"
User = user1
Name = pap
Env = dev
Role = dev

Explanation:

NR == 1      # For first row save headers in an array called hdr
$col == val  # when passed val is same as the value of column indicated by col

edited May 8, 2015 at 10:00

answered May 7, 2015 at 11:01

anubhava

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7 Comments

user2112700 Over a year ago

May I know how you are passing the filename parameter ?

user2112700 Over a year ago

I am not getting output and also no errors. Any idea ?

anubhava Over a year ago

Run this awk directly from command line like this:

awk -v col=3 -v val='dev' 'NR==1{for (i=1; i<=NF; i++) hdr[i]=$i; next} $col == val {for (i=1; i<=NF; i++) print hdr[i], "=", $i; exit}' file

. This gives me output attached in answer.

user2112700 Over a year ago

I have tried it as command also, but the same problem. Couldn't figure out.

anubhava Over a year ago

That means your file is not same as shown in question. Using cat -vte file check whether you have DOS line ending. If yes then run dos2unix to convert to unix file.

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