On Wed, Jun 8, 2016 at 5:10 AM, leif <not.rea...@online.de> wrote: > Jeroen Demeyer wrote: >> On 2016-06-08 00:14, William Stein wrote: >>> On Tue, Jun 7, 2016 at 6:12 PM, Francois Bissey >>> <francois.bis...@canterbury.ac.nz> wrote: >>>> The version from the sage-on-gentoo overlay has been hacked to >>>> explicitly >>>> write data generated by the user in ~/.sympow. If indeed you make a >>>> system >>>> wide install where the user cannot write it will certainly fail. >>> >>> This is indeed exactly why it fails for me (silently from within sage >>> and with a segfault from the command line). >> >> So sympow *segfaults* if it cannot open a file? > > That's pretty easy to achieve: > > fp=fopen("/youre/not/allowed/to/access/this/folder/foo","w"); > /* don't check the return value */ > fwrite("booom!",1,6,fp); > > You'll normally get a warning because frwite() etc. carry the > warn_unused_result attribute, but not for fopen() since NULL is assigned > to fp in case it fails. > > > -leif
Thanks. Here is the *actual* code from sympow: fclose(F); printf("Left with %i entries in param_data\n",i); F=fopen("datafiles/param_data","w"); ... -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.