Solaris 9 32-bit application 256 descriptors

Question

Hi,
There is a bug in Solaris, a 32-bit application running on 64-bit Solaris cannot open more than 256 descriptors. I read the article from Giri Mandalika http://developers.sun.com/solaris/articles/stdio_256.html. There is a solution for Solaris 10 described in that article. Is there any solution for Solaris 9? Was that solution backported to Solaris 9?
Any hint is appreciated.
Tomas

Answer 1

Hello.
This limitation is not a limitation of the Solaris operating system but of the libc library.
A simple workaround could be:
FILE *myfiles[1000];
int i;
// won't work if more than 256 files are open...
for(i=0;i<1000;i++) myfiles=fopen(names[i],"w");
for(i=0;i<1000;i++) fprintf(myfiles[i],"%u\n",i);
Workaround - NOT TESTED:FILE *f;
int myfiles[1000];
int i;
for(i=0;i<1000;i++) myfiles[i]=creat(names[i],0644);
for(i=0;i<1000;i++)
f=fdopen(dup(myfiles[i]),"w");
fprintf(f,"%u\n",i);
// fclose() will only close the handle duplicate returned by dup() !!
fclose(f);
-- EDIT --
Tested on Solaris 9/Sparc:
- You have to use "ulimit -n" to allow an application to use more than 256 file descriptors (maximum is 1024).
- If more than 256 files are open "dup" and "dup2" will cause an SIGSEGV - obviously a bug in Solaris.
  Maybe you can use the following combination instead of using "fprintf":len=sprintf(buffer,...);
write(file[i],buffer,len);
  I'm not sure if "write" etc. cause SIGSEGVs when more than 256 files are open.
Martin