man: Refer to pcap-filter(7) early. [skip ci]

(cherry picked from commit 4a904f4362e9f47acd933b14efe022c635874ecc)

diff --git a/tcpdump.1.in b/tcpdump.1.in
index 02d1ef8a4940c0a6d06672ce9f1f576c7d0a635f..1e2e432bd77f957d2537c418887aacb66bac3b32 100644 (file)
--- a/tcpdump.1.in
+++ b/tcpdump.1.in
@@ -152,7 +152,9 @@ tcpdump \- dump traffic on a network
 .SH DESCRIPTION
 .LP
 \fITcpdump\fP prints out a description of the contents of packets on a
-network interface that match the Boolean \fIexpression\fP; the
+network interface that match the Boolean \fIexpression\fP (see
+.BR pcap-filter (7)
+for the \fIexpression\fP syntax); the
 description is preceded by a time stamp, printed, by default, as hours,
 minutes, seconds, and fractions of a second since midnight.  It can also
 be run with the