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sebelk

10-08-2010 11:53 AM

awk: swap fields given a condition

Hi,

I have a file records as follows:

Jane pepe@pepe.biz
john@pepe.net John
Joe joe@willxyz.org

How can I get that always first field be given name and second one be the mail address?

I've tried

Code:

awk '$1 ~ /@/ { a=$1 ; $1=$2; $2=a; print }' file

But that doesn't worked

TIA

MensaWater

10-08-2010 12:19 PM

Not with awk but this little script would do it:

Code:

#!/bin/bash

while read first second

do if echo $first |grep \@ >/dev/null 2>&1

  then echo $second $first

  else echo $first $second

  fi

done

Just run the script with redirect in from file. So if you named the script "reorder.sh" you'd run it as:

Code:

reorder.sh <file

Where file is the name of the file with the original data. Should output:
Jane pepe@pepe.biz
John john@pepe.net
Joe joe@willxyz.org

GrapefruiTgirl

10-08-2010 01:09 PM

Here's a working fix-up of your awk code. I think the main problem with your original method was trying to assign values to fields, but you didn't tell us what exactly was happening when your code didn't work, so I'm guessing about that.

Anyhow, you don't need to assign anything to anything - just print the fields in the opposite order if the email address comes first; otherwise, print the record as it is:

Code:

awk '{ if ($1 ~ /@/){printf $2" "$1"\n"} else {print} }' filename

Best regards.

ghostdog74

10-08-2010 07:39 PM

Code:

awk '$1~/@/{t=$1;$1=$2;$2=t}1' file

GrapefruiTgirl

10-08-2010 07:49 PM

Thanks ghostdog74,

so what I see is:

OP had the exact right idea, only should have had the print statement outside the braces (where you've used a 1 instead)?

And, we can reassign fields to different values. I didn't know that!

Thanks,
Sasha

ghostdog74

10-08-2010 08:17 PM

Quote:

Originally Posted by GrapefruiTgirl (Post 4121990)

(where you've used a 1 instead)?

"1" is just a shortcut for print, i am sure you already know.

Quote:

And, we can reassign fields to different values. I didn't know that!

yes, but take note it will change the FS. Assign OFS if needed.

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