RE: Input line splitting and OFS

[address@hidden]

Thank you to everyone who has responded to my question.

As I explained, I was mainly looking for an explanation as to why, and you've 
all made valid points in that regard, in particular about FS possibly be a 
regex, and you've also given me some useful tips such as the difference between 
resplitting and rebuilding.

As for my code itself, this was given purely as an example, and doesn't look at 
all like my actual app which is an interpreter for a small language. For this 
I've moved to reading $0 into an array before parsing, which has solved all of 
my splitting issues which were linked to substituting "macro" expressions back 
into the original input line.

I've been using awk/gawk for one-liners and short scripts for over 30 years, 
but this is the first time I've attempted anything this major. Once the 
prototype is stable enough I'll most likely port it to a different language, 
probably python, and provide a UI, but in the meantime awk is great for what I 
need. Even in its unfinished state the app has already saved me hours of time 
both at work and at home, and provided much enjoyment :)

Best regards,
Chris

-----Original Message-----
From: address@hidden [mailto:address@hidden] 
Sent: 16 November 2019 18:35
To: Newell, Christopher (IE Dundrum); address@hidden
Subject: Re: Input line splitting and OFS

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Hi.

"address@hidden" <address@hidden> wrote:

> Hi,
>
> I have a question about the use of OFS as it relates to field splitting.

OFS has been used to rebuild the record since awk was first invented
in the late 1970s.

As to "why?" I would have to guess that as OFS is used for output, and
most of the time the record is rebuilt in order to output it, that
using OFS made sense.

Additionally, as of 1987's "new" awk, when FS became it a regular expression,
using FS would make even less sense.

I hope this and the other answers have helped.

Thanks,

Arnold

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