[GAP Forum] Gap doesn't quit automatically when running in script mode.

[Hongyi Zhao]

On Sat, Apr 30, 2022 at 5:29 PM Dima Pasechnik <dima at sagemath.org> wrote:
>
> On Sat, Apr 30, 2022 at 05:16:09PM +0800, Hongyi Zhao wrote:
> > On Sat, Apr 30, 2022 at 4:26 PM Dima Pasechnik <dima at sagemath.org> wrote:
> > >
> > > On Sat, Apr 30, 2022 at 02:57:22PM +0800, Hongyi Zhao wrote:
> > > > Hi GAP team,
> > > >
> > > > I'm running the following script to compute the irreducible
> > > > representations of small abstract groups with gap:
> > > [...]
> > >
> > > > I run the above script as follows:
> > > >
> > > > $ gap abstract-group-irrep.gap > out
> > > >
> > > > But I noticed that gap will hang there forever, even the job has been
> > > > finished, till I hit `Ctrl + d` to terminate it. Any hints for letting
> > > > it exits automatically?
> > >
> > >
> > > There is a command to quit GAP,
> > >
> > > gap> quit;
> >
> > But I want to run the script in a completely non-interactive manner.
> You can put "quit;" in the srcipt, why not?

Very strange. I've taken this command as the last line in my script:

$ cat abstract-group-irrep.gap
#!/usr/bin/env gap

#https://vixra.org/pdf/1507.0089v1.pdf
LoadPackage("SONATA") ;;
LoadPackage("ctbllib") ;;
irrforgroup := function(g)
local els,e,gid,fna,ir,irr,id ;
Print("---------------\n") ;
els := Elements(g) ;;
gid := IdGroup(g) ;;
Print(gid,"\n") ;
# print elements by generators
id := 1 ;;
for e in els do
if id > 1 then
Print(id,"=",els[id],". ") ;
fi;
id := id+1 ;
od;
Print("\n") ;

Print(StructureDescription(g),"\n") ;
ir := IrrDixonSchneider(g) ;;
Print(ir) ;
Display(CharacterTable(g)) ;
Irr(g) ;;
irr := IrreducibleRepresentationsDixon(g) ;;
Print(irr,"\n") ;
end;;
# need to start at n=2 because n=1 hangs up the
IrreducibleRepresetations(g) part
for n in [2..36] do
alls := AllSmallGroups(n) ;
for g in alls do
irrforgroup(g) ;
od ;
od;

quit;

When I run it as follows, the terminal will freeze with the following
information forever:

$ gap abstract-group-irrep.gap >/dev/null
Reading file "abstract-group-irrep.gap" has been aborted.

> HTH
> Dima

Yours,
Hongyi