Extract value of column from a line (variable)
Solution 1
You can use awk
to get second field:
line="abc:123:def:345"
awk -F: '{print $2}' <<< "$line"
123
Solution 2
To assign a variable in the shell, no $
on the left-hand side, no spaces around the =
, and <
and >
are not valid quote characters
line="abc:123:def:345"
In bash, you would do this:
IFS=: read -ra fields <<< "$line"
- temporarily set
IFS
to a colon - use the
$line
variable as input to theread
command (a here-string) - and read the values into the
fields
array.
Bash arrays are indexed starting from zero, so to extract the 2nd field:
echo "${fields[1]}" # => 123
user4516211
Updated on June 27, 2022Comments
-
user4516211 over 1 year
Okay, so I have a variable ($line) that is defined in the bash/shell script as
$line = "abc:123:def:345"
need to get this column2 = "123"
How do I extract the value of the 2nd column i.e. "123" and name it as a different variable which can be summed later on? I know you have to separate it based on the delimiter ':' but I don't know how to transfer to different variable whilst taking input from $line variable. I only ask this because for some weird reason my code reads the first line of text file BUT doesn't perform the awk on just the first line only so hence the sum is wrong.
FILE=$1 while read line do awk -F: '{summation += $3;}END{print summation;}' done < $FILE
-code via shell script
Thanks.