Re: [bug-gawk] Strange behavior in gawk

[Andrew J. Schorr]

On Sun, Dec 07, 2014 at 01:52:04AM +0100, Davide Brini wrote:
> This is becoming sort of a FAQ, please read 
> 
> https://www.gnu.org/software/gawk/manual/gawk.html#Field-Splitting-Summary
> 
> the box titled "Changing FS Does Not Affect the Fields". To workaround your
> issue you can use split(), or change FS before awk attempts to read the
> line in question (ie, at the end of the previous one).

Another solution is to reassign $0.  If you change your script to say:

/:/ {
    FS=":"
    $0 = $0
    print "NF = " NF " - " $0
}

/\./ {
    FS="."
    $0 = $0
    print "NF = " NF " - " $0
}

Then you will get the desired results:

NF = 3 - 1:2:3
NF = 3 - 4:5:6
NF = 4 - .a.b.c
NF = 4 - .e.f.g

Regards,
Andy