Re: MAX_ARG_STRLEN

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

On Thu, May 07, 2026 at 12:13:43PM -0400, Igor Schein wrote:
> Hi,
> 
> I thought I had hit a bug in galoisexport(), but eventually I figured
> out what I was actually hitting was the MAX_ARG_STRLEN limitation when
> passing output of galoisexport() longer than MAX_ARG_STRLEN to an
> external program via extern().  This is just an FYI, in case someone
> else runs into this.  I rewrote my tools to use temporary files
> instead, and everything is peachy now.

Note that you can use a pipe now:

? gapident(G)=my(f=fileextern("gap -q","w"));filewrite(f,Str("IdGroup(",galoisexport(G),");\n")); fileclose(f);
? G=galoisinit(polcyclo(48));
? gapident(G)
[ 16, 10 ]

But it does not allow you to capture the result.

Cheers,
Bill.