How to cut (select) a field from text line counting from the end?

I know how to select a field from a line using the cut command. For instance, given the following data:

a,b,c,d,e
f,g,h,i,j
k,l,m,n,o

This command:

cut -d, -f2 # returns the second field of the input line

Returns:

b
g
l

My question: How can I select the second field counting from the end? In the previous example, the result would be:

d
i
n

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Answers:

Method 1

Method 2

Method 3

Explanation

Answers:

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Method 1

Reverse the input before and after cut with rev:

<infile rev | cut -d, -f2 | rev

Output:

d
i
n

Method 2

Try doing this with awk :

awk -F, '{print $(NF-1)}' file.txt

Or using perl :

perl -F, -lane 'print $F[-2]' file.txt

Or using ruby (thanks manatwork) :

ruby -F, -lane 'print $F[-2]' file.txt

Or using bash (thanks manatwork) :

while IFS=, read -ra d; do echo "${d[-2]}"; done < file.txt

Or using python :

cat file.txt |
python -c $'import sysnfor line in sys.stdin:tprint(line.split(",")[-2])'

Method 3

Using sed:

sed -E 's/^([^,]*,)*([^,]*)(,[^,]*){1}$/2/' infile

Output:

d
i
n

Explanation

([^,]*,)* matches any number of non-comma charecter followed by a comma, i.e. any number of columns.
([^,]*) matches a column.
(,[^,]*){1} matches one column at the end, if you change the quantifier {1} to {2} it matches the third column from the end etc.

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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