Hi Russ,
> Given a file of lines in a file like below, what would be the best way to replace the last item on each line (e.g. V6 in the last line)?
> twa01.dat 16 2000 16 0 5 -29501 0 V6
Why not `:gsub("%S+$", "newval")`?
Paul.
Hi Paul. To answer your question: because I have no idea what I'm doing. I really suck at string manipulation in Lua and I'm equally poor in regex in any other language. I tried it as you've written it with no matches. The Lua reference manual doesn't seem to indicate that capital %S does anything (but I could be missing something). I changed it to a lowercase %s and got closer to what I need:
local i = 0
for line in io.lines(file_name) do
if line:match('.dat') then
i = i + 1
local l = line:gsub("%s+$", "newval"..i)
print(l)
end
end
end
results in:
russellh@canary-dev:~/physionet/get_stats$ ./modify_headers.lua --rec twa01
twa01.dat 16 2000 16 0 12 10980 0 Inewval1
twa01.dat 16 2000 16 0 14 -9048 0 IInewval2
twa01.dat 16 2000 16 0 1 -25727 0 IIInewval3
twa01.dat 16 2000 16 0 -14 29120 0 aVRnewval4
twa01.dat 16 2000 16 0 5 15064 0 aVLnewval5
twa01.dat 16 2000 16 0 8 17036 0 aVFnewval6
twa01.dat 16 2000 16 0 2 19694 0 V1newval7
twa01.dat 16 2000 16 0 12 26289 0 V2newval8
twa01.dat 16 2000 16 0 21 -23938 0 V3newval9
twa01.dat 16 2000 16 0 18 11347 0 V4newval10
twa01.dat 16 2000 16 0 6 27591 0 V5newval11
twa01.dat 16 2000 16 0 5 -29501 0 V6newval12
So, it's close but not removing the original value?
Thanks for your help (And thank you to Gabriel as well!),
Russ
On Wed, Jun 26, 2019 at 10:45 AM Russell Haley <russ.haley@gmail.com> wrote:
>
> Hi,
>
> Given a file of lines in a file like below, what would be the best way to replace the last item on each line (e.g. V6 in the last line)?
>
> twa01.dat 16 2000 16 0 12 10980 0 I
> twa01.dat 16 2000 16 0 14 -9048 0 II
> twa01.dat 16 2000 16 0 1 -25727 0 III
> twa01.dat 16 2000 16 0 -14 29120 0 aVR
> twa01.dat 16 2000 16 0 5 15064 0 aVL
> twa01.dat 16 2000 16 0 8 17036 0 aVF
> twa01.dat 16 2000 16 0 2 19694 0 V1
> twa01.dat 16 2000 16 0 12 26289 0 V2
> twa01.dat 16 2000 16 0 21 -23938 0 V3
> twa01.dat 16 2000 16 0 18 11347 0 V4
> twa01.dat 16 2000 16 0 6 27591 0 V5
> twa01.dat 16 2000 16 0 5 -29501 0 V6
>
> I'm not even having much luck with simply capturing the separate items. I've tried a bunch of variations on this:
>
> for line in io.lines(file_name) do
> if line:match('.dat') then
> local t = {}
> for v in line:gmatch('%s(.)') do
> t[#t+1] = v
> end
> for i,v in pairs(t) do
> print(i,v)
> end
> end
> end
>
> Any advice would be appreciated.
>
> Thanks!
> Russ
