Re: [bug-gawk] Gawk Enhancement Suggestion

[arnold]

Hi Ed.

I don't see this as being enough useful to require making it a builtin.
It's just more code to maintain and document that won't get a lot of use.

I think an awk function is the best way to go, but if you want to
contribute a loadable function written in C that would work too.

Thanks,

Arnold

> Date: Wed, 14 Dec 2011 16:22:37 -0600
> From: Ed Morton <address@hidden>
> To: Aharon Robbins <address@hidden>
> CC: address@hidden
> Subject: Re: [bug-gawk] Gawk Enhancement Suggestion
> 
> Arnold - I'll take a look and get back to you. I expect I can code up
> what I have in mind (which isn't quite what's in that example) as an awk
> function that people could copy/paste but I was really hoping to get a
> new builtin string function out of this.
> 
> Thanks,
> 
>      Ed.
> 
> On 12/6/2011 2:38 PM, Aharon Robbins wrote:
> > Hi Ed.
> >
> > Re the below. See the node "Cut Program" in the gawk manual.
> > Adaptation into a function should be straightforward.
> >
> > A diff to redo that section as a function + code to call it will
> > be cheerily reviewed and most likely accepted.
> >
> > Thanks,
> >
> > Arnold
> >
> >> Date: Fri, 02 Dec 2011 07:36:50 -0600
> >> From: Ed Morton<address@hidden>
> >> To: address@hidden
> >> Subject: [bug-gawk] Gawk Enhancement Suggestion
> >>
> >> Arnold - could we get a "cut()" function for gawk similar to the UNIX
> >> one of the same name that just lets people select specific fields or
> >> ranges of fields?  Below is some details (copied from something I posted
> >> at comp.lang.awk).
> >>
> >> Regards,
> >>
> >>       Ed.
> >>
> >> A function that returns a string of selected fields is very often all we 
> >> need. e.g.:
> >>
> >> print cut($0,3)       # print from the 3rd field to the end of the record 
> >> using
> >> FS as separator
> >> print cut($0,3,",")   # print from the 3rd field to the end of the record 
> >> using
> >> "," as separator
> >> print cut($0,"3-7")   # print from the 3rd field to the 7th field
> >> print cut($0,"3,5,7") # print the 3rd, 5th, and 7th fields
> >>
> >> The separating substring between the fields would just be whatever 
> >> separator
> >> preceeded the trailing fields. So, with this input (with leading blanks):
> >>
> >>       a b    c  d
> >>
> >> the following code snippets would produce the output that follows them:
> >>
> >> print cut($0,"1,3")
> >> a    c
> >>
> >> print cut($0,"1,3",/[[:blank:]]+/)
> >>    b
> >>
> >> print cut($0,"1-3")
> >> a b    c
> >>
> >> print cut($0,"2,4")
> >> b  d
> >>
> >> print cut($0,"1-4")
> >> a b    c  d
> >>
> >> Obviously $0 can be replaced by any string and cut() should take an 
> >> optional 4th
> >> arg to specify the separator in it's returned string:
> >>
> >> print cut($0,"1,3",FS,OFS)
> >> a c
> >>
> >> print cut($0,"1,3",/[[:blank:]]+/,"#")
> >> #b
> >>
> >> print cut($0,"1-3",FS,OFS)
> >> a b c
> >>
> >> print cut($0,"2,4",FS,":")
> >> b:d
> >>
> >> print cut($0,"1-4",FS,"|")
> >> a|b|c|d
> >>
>