Remove first 2 columns from first row of a file

Question

I am looking for a command to remove first 2 columns from the first row of a file. The delimiter for the columns is a pipe. Number of columns vary.

we just need to blindly remove first 2 columns. sample below.

input: col1|col2|col3|col4

output col3|col4

Answer 1

Probably the simplest command is

sed '1s/^[^|]*|[^|]*|//g' input > output

This sed command will only on line 1 do the substitution.

For this input:

foo|bar|baz|doo|bee|doo
123|456
789|101|112

it will produce that output:

baz|doo|bee|doo
123|456
789|101|112

Answer 2

try this command

head -2 inputFile.txt | cut -d "|" -f 3- > outputFile.txt

Answer 3

The cut command should do the job if I guess at what you are referring to.

echo "foo|bar|baz" | cut -d"|" -f3

So if you are only wanting to edit the first row then use the head command as well.

head -n1 filename | cut -d"|" -f3

You could also use sed to do the job.

head -n1 filename | sed 's/^.*|.*|//g'

Answer 4

This will cut out the first 2 pipe-delimited fields of line 1, and copy the rest of the file (line 2 onward) without changes.

(head -n 1 input | cut -d '|' -f 3- ; tail -n +2 input) > output

A slightly more efficient but syntactically trickier way to do it is:

{ head -n 1 input | cut -d '|' -f 3- ; tail -n +2 input; } > output