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Diffstat (limited to 'pcap_get_selectable_fd.3pcap')
-rw-r--r--pcap_get_selectable_fd.3pcap12
1 files changed, 9 insertions, 3 deletions
diff --git a/pcap_get_selectable_fd.3pcap b/pcap_get_selectable_fd.3pcap
index 6ae06a1b..6640577e 100644
--- a/pcap_get_selectable_fd.3pcap
+++ b/pcap_get_selectable_fd.3pcap
@@ -36,9 +36,9 @@ int pcap_get_selectable_fd(pcap_t *p);
returns, on UNIX, a file descriptor number for a file descriptor on
which one can
do a
-.B select()
-or
-.B poll()
+.BR select() ,
+.BR poll() ,
+or other such call
to wait for it to be possible to read packets without blocking, if such
a descriptor exists, or \-1, if no such descriptor exists. Some network
devices opened with
@@ -54,6 +54,12 @@ or
(for example, regular network devices on FreeBSD 4.3 and 4.4, and Endace
DAG devices), so \-1 is returned for those devices.
.PP
+Note that a descriptor on which a read can be done without blocking may,
+on some platforms, not have any packets to read if the read timeout has
+expired. A call to
+.B pcap_dispatch()
+will return 0 in this case, but will not block.
+.PP
Note that in:
.IP
FreeBSD prior to FreeBSD 4.6;