Hi,
I have written a daemon process, to perform certain operations in the background.
For this I have to close, the open file descriptors,
Does anybody know how to find out the number of open file descriptors ?
Thanks in Advance,
Sheetal (2 Replies)
I have set the maximum no of file descriptors open in a process to the value 8192 using the following lines
set rlim_fd_max=8192
set rlim_fd_cur=8192
in the /etc/system file.
I rebooted the machine and the command ulimit -n / -Hn both display the limits as 8192. However when I run my... (2 Replies)
An application running on HP-UX constantly generates new text log files ( I think using logpipe ). Any new file created requires to be ftp'ed to an offline server, however I want to make sure that the current file being written should not be transferred.
For examples consider the following files... (3 Replies)
I'm trying to set the open files value to 4000 on a SLES 9 system.
Current values:ulimit -n
1024
I can set it using this:ulimit -n 4000
ulimit -n
4000
But this obviously sets it only for the shell session where I run the command to set it. I want to set this to 4000 for all time.
... (3 Replies)
I want to press "apple + T" to open a new terminal tab. This terminal tab must be in the same directory as the current one. Anyone knows how to do that?
Thanks a lot! (1 Reply)
Hi
How to increase maximum number of open file in "sco xenix binary" running in "sco unix openserver 5.0.7" ?
I have changed "NOFILES" kernel parameter to 512, but xenix binray can't open more than 60.
tnx (4 Replies)
Hi guys,
i need to write a shell script that will close file descriptors from /proc/pid/fd
will calling exec 4<&- solve the problem ?
thanks in advance :) (15 Replies)
I wrote a perl program that simultaneously reads in data from 691 tar.gz files using zcat. I can run one instance of the program without any issues and the memory and swap sizes are negligible. However, when I attempt to run more than 1 I start to get fork: resource unavailable messages. Are... (6 Replies)
Ubuntu users,
I am configuring an Ubuntu 14.04 server as a load injector.
I have appended the hard and soft limits to /etc/security/limits.conf for any user (apart from root):
* hard nofile 65536
* soft nofile 65536
I am seeing the figure 65536 in... (5 Replies)
Hello!
I am studying a course about computers using unix commands and I'm wondering how I can copy files from a file when I am on a different one in coding?
The question says what command copies the file fickur that is in the catalogue fickur to the catalogue digital?
current open... (1 Reply)
Discussion started by: Northernlightif
1 Replies
LEARN ABOUT OPENSOLARIS
closefrom
closefrom(3C) Standard C Library Functions closefrom(3C)NAME
closefrom, fdwalk - close or iterate over open file descriptors
SYNOPSIS
#include <stdlib.h>
void closefrom(int lowfd);
int fdwalk(int (*func)(void *, int), void *cd);
DESCRIPTION
The closefrom() function calls close(2) on all open file descriptors greater than or equal to lowfd.
The effect of closefrom(lowfd) is the same as the code
#include <sys/resource.h>
struct rlimit rl;
int i;
getrlimit(RLIMIT_NOFILE, &rl);
for (i = lowfd; i < rl.rlim_max; i++)
(void) close(i);
except that close() is called only on file descriptors that are actually open, not on every possible file descriptor greater than or equal
to lowfd, and close() is also called on any open file descriptors greater than or equal to rl.rlim_max (and lowfd), should any exist.
The fdwalk() function first makes a list of all currently open file descriptors. Then for each file descriptor in the list, it calls the
user-defined function, func(cd, fd), passing it the pointer to the callback data, cd, and the value of the file descriptor from the list,
fd. The list is processed in file descriptor value order, lowest numeric value first.
If func() returns a non-zero value, the iteration over the list is terminated and fdwalk() returns the non-zero value returned by func().
Otherwise, fdwalk() returns 0 after having called func() for every file descriptor in the list.
The fdwalk() function can be used for fine-grained control over the closing of file descriptors. For example, the closefrom() function can
be implemented as:
static int
close_func(void *lowfdp, int fd)
{
if (fd >= *(int *)lowfdp)
(void) close(fd);
return(0);
}
void
closefrom(int lowfd)
{
(void) fdwalk(close_func, &lowfd);
}
The fdwalk() function can then be used to count the number of open files in the process.
RETURN VALUES
No return value is defined for closefrom(). If close() fails for any of the open file descriptors, the error is ignored and the file
descriptors whose close() operation failed might remain open on return from closefrom().
The fdwalk() function returns the return value of the last call to the callback function func(), or 0 if func() is never called (no open
files).
ERRORS
No errors are defined. The closefrom() and fdwalk() functions do not set errno but errno can be set by close() or by another function
called by the callback function, func().
FILES
/proc/self/fd directory (list of open files)
USAGE
The act of closing all open file descriptors should be performed only as the first action of a daemon process. Closing file descriptors
that are in use elsewhere in the current process normally leads to disastrous results.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|MT-Level |Unsafe |
+-----------------------------+-----------------------------+
SEE ALSO close(2), getrlimit(2), proc(4), attributes(5)SunOS 5.11 27 Apr 2000 closefrom(3C)