NetBSD/gnu/dist/postfix/util/open_limit.c

81 lines
1.6 KiB
C

/*++
/* NAME
/* open_limit 3
/* SUMMARY
/* set/get open file limit
/* SYNOPSIS
/* #include <iostuff.h>
/*
/* int open_limit(int limit)
/* DESCRIPTION
/* The \fIopen_limit\fR() routine attempts to change the maximum
/* number of open files to the specified limit. Specify a null
/* argument to effect no change. The result is the actual open file
/* limit for the current process. The number can be smaller or larger
/* than the requested limit.
/* DIAGNOSTICS
/* open_limit() returns -1 in case of problems. The errno
/* variable gives hints about the nature of the problem.
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System libraries. */
#include "sys_defs.h"
#include <sys/time.h>
#include <sys/resource.h>
#include <errno.h>
/* Application-specific. */
#include "iostuff.h"
/*
* 44BSD compatibility.
*/
#ifndef RLIMIT_NOFILE
#ifdef RLIMIT_OFILE
#define RLIMIT_NOFILE RLIMIT_OFILE
#endif
#endif
/* open_limit - set/query file descriptor limit */
int open_limit(int limit)
{
#ifdef RLIMIT_NOFILE
struct rlimit rl;
#endif
if (limit < 0) {
errno = EINVAL;
return (-1);
}
#ifdef RLIMIT_NOFILE
if (getrlimit(RLIMIT_NOFILE, &rl) < 0)
return (-1);
if (limit > 0) {
if (limit > rl.rlim_max)
rl.rlim_cur = rl.rlim_max;
else
rl.rlim_cur = limit;
if (setrlimit(RLIMIT_NOFILE, &rl) < 0)
return (-1);
}
return (rl.rlim_cur);
#endif
#ifndef RLIMIT_NOFILE
return (getdtablesize());
#endif
}