Re: Insertion of extra OFS character into output string

[Neil R. Ormos]

H wrote:

> I am a newcomer to awk and have run into an
> issue I have not figured out yet... My platform
> is CentOS 7 running awk 4.0.2, the default
> version.

> The following awk statement generates an extra
> tab character between fields 1 and 2, regardless
> of the data in the file:

> awk 'BEGIN{FS=","; FPAT="([^,]*)|(\"[^\"]+\")"; OFS="\t"} {$1=$1; gsub(/"/, 
> ""); print}' somefile.csv

> If i change the statement to:

> awk 'BEGIN{FS=","; FPAT="([^,]*)|(\"[^\"]+\")"; OFS="\t"} {$2=$2; gsub(/"/, 
> ""); print}' somefile.csv

> an extra OFS character is inserted between
> fields two and three. I can add that removing
> the gsub() in either of the two examples does
> not affect the results.

> Might this be a bug in 4.0.2 or a feature I have
> not yet understood?

I don't have 4.0.2 available to test, but I tested with older and newer 
versions.

When I test, I get the result I think I expect from the code you posted.

Also, setting FPAT overrides the effect of having earlier set FS.  (I believe 
that the most-recently set one among FS, FPAT, and FIELDWIDTHS controls the 
field splitting operation.)

echo "1,2" | awk 'BEGIN{FS=","; FPAT="([^,]*)|(\"[^\"]+\")"; OFS="\t"} {$1=$1; 
print}' | hexdump -c
0000000   1  \t   2  \n
0000004

It would be easier to help if you would please provide:

  the simplest input line that reproduces the problem;

  the output you expect; and

  the output you are getting.