Lum – Swapping an unlimited number of columns

Almost there. Just put both column references next to each other.

cat logfile | sed 's/|/ /' | awk '{print $1, $8}'

Also note that you don't need cat here.

sed 's/|/ /' logfile | awk '{print $1, $8}'

Also note you can tell awk that the column separators is |, instead of blanks, so you don't need sed either.

awk -F '|' '{print $1, $8}' logfile

As per suggestions by Caleb, if you want a solution that still outputs the last field, even if there are not exactly eight, you can use $NF.

awk -F '|' '{print $1, $NF}' logfile

Also, if you want the output to retain the | separators, instead of using a space, you can specify the output field separators. Unfortunately, it's a bit more clumsy than just using the -F flag, but here are three approaches.

• You can assign the input and output field separators in awk itself, in the BEGIN block.

  awk 'BEGIN {FS = OFS = "|"} {print $1, $8}' logfile
  

• You can assign these variables when calling awk from the command line, via the -v flag.

  awk -v 'FS=|' -v 'OFS=|' '{print $1, $8}' logfile
  

• or simply:

  awk -F '|' '{print $1 "|" $8}' logfile