• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 393
  • Last Modified:

File Descriptors - How many?

I have a C++ program that is running on a unix machine.  I need to find out exactly how many file descriptors I have left.  I have a lot of socket connections opened and reading the output.  I am running into problems with some of the file descriptors I get a "Bad File Number".  I would like to exactly how many I have left.  Any ideas?

Is there a way to find out how many file descriptors I have left for the entire system as well as how many per process?
0
sgrobins
Asked:
sgrobins
  • 2
1 Solution
 
ozoCommented:
#include <stdio.h>
define NFILE FOPEN_MAX
0
 
ozoCommented:
#include <sys/resource.h>
struct rlimit rl;
getrlimit(RLIMIT_NOFILE,&rl);

#include <ulimit.h>
limit=ulimit(UL_GDESLIM);
0
 
sgrobinsAuthor Commented:
I am using the gerlimit and setrlimit to set the maximum file descriptors allowed in my program.  I have set it to 1024.  What I would like to do is as the program is running see how many file descriptors are in use.  Is this possible?
0
 
Rajkumar_RCommented:
See the man page for select ! You can set all the bits from 0 to 1024  and using the call select you can check how many is readable how many is writable ...etc ...which ever is suitable to your logic !
eg:-

fd_set myfd;
FD_ZERO(&stFDset);      

for (i=0; i< 1024;i++ )
     FD_SET(i,&myfd);  

then call the select first to check how many is readable ..and then next to see how many is writable or both at once !

Please let me know if you need more details !

0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now