awk - how to delete first column with field separator

Question

I have a csv file with data presented as follows

87540221|1356438283301|1356438284971|1356438292151697
87540258|1356438283301|1356438284971|1356438292151697
87549647|1356438283301|1356438284971|1356438292151697

I'm trying to save the first column to a new file (without field separator , and then delete the first column from the main csv file along with the first field separator.

Any ideas?

This is what I have tried so far

awk 'BEGIN{FS=OFS="|"}{$1="";sub("|,"")}1'

but it doesn't work

What about cut? `cut -d '|' -f 2-` – squiguy May 08 '13 at 18:58 — squiguy, May 08 '13 at 18:58

score 18 · Answer 1 · answered May 08 '13 at 19:00

This is simple with cut:

$ cut -d'|' -f1 infile
87540221
87540258
87549647

$ cut -d'|' -f2- infile
1356438283301|1356438284971|1356438292151697
1356438283301|1356438284971|1356438292151697
1356438283301|1356438284971|1356438292151697

Just redirect into the file you want:

$ cut -d'|' -f1 infile > outfile1

$ cut -d'|' -f2- infile > outfile2 && mv outfile2 file

score 7 · Accepted Answer · answered May 08 '13 at 18:59

7

Assuming your original CSV file is named "orig.csv":

awk -F'|' '{print $1 > "newfile"; sub(/^[^|]+\|/,"")}1' orig.csv > tmp && mv tmp orig.csv

answered May 08 '13 at 18:59

Ed Morton

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`awk` solution works x20 times faster than `cut`. Tested on 15Gb CSV file. – Kirzilla Jun 05 '14 at 14:38

Zombo · Answer 3 · 2014-12-26T06:14:49.403

3

GNU awk

awk '{$1="";$0=$0;$1=$1}1' FPAT='[^|]+' OFS='|'

Output

1356438283301|1356438284971|1356438292151697
1356438283301|1356438284971|1356438292151697
1356438283301|1356438284971|1356438292151697

edited Dec 26 '14 at 06:14

answered Nov 18 '14 at 06:20

Zombo

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How does it work? – darw Aug 24 '22 at 14:28
@darw Sets `$1` null. `$0=$0` resplits the record, which now starts with a `|` (the OFS). FPAT doesn't match a null, so `$1` is now the (former) second field. `$1=$1` causes a rebuild of the output record, with `OFS='|'`. The trailing `{...}1` is a shorthand for print: It is the pattern of a second pattern-action pair, and is boolean "true". With no action, awk defaults to `{print}`. gawk recognises variable settings after the program text without needing a `-v`. – Douglas Royds Aug 11 '23 at 07:25

score 1 · Answer 4 · answered May 08 '13 at 19:00

Pipe is special regex symbol and sub function expectes you to pass a regex. Correct awk command should be this:

awk 'BEGIN {FS=OFS="|"} {$1=""; sub(/\|/, "")}'1 file

OUTPUT:

1356438283301|1356438284971|1356438292151697
1356438283301|1356438284971|1356438292151697
1356438283301|1356438284971|1356438292151697

score 0 · Answer 5 · answered Nov 18 '14 at 14:49

0

With sed :

sed 's/[^|]*|//' file.txt

answered Nov 18 '14 at 14:49

rook

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awk - how to delete first column with field separator

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