How to identify/get QLogic/Emulex WWN on Red Hat Enterprise Linux 5 (RHEL5).

First identify your installed or recognized

# lspci | grep -i fibre
04:00.0 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 03)
04:00.1 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 03)
05:00.0 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 03)
05:00.1 Fibre Channel: QLogic Corp. ISP2432-based 4Gb Fibre Channel to PCI Express HBA (rev 03)

On  Red Hat Enterprise Linux 5 (5.x) is on /sys/class/fc_host/hostX/port_name
(X is your device 1,2,3,…N)
For get use:

cat /sys/class/fc_host/hostX/port_name

Sample with multiple HBA (Fibre) QLogic

# ls /sys/class/fc_host/
host3  host4  host5  host6
# cat /sys/class/fc_host/host[3-6]/port_name
0x2100001b32936e24
0x2101001b32b36e24
0x2100001b32932821
0x2101001b32b32821

On Red Hat Enterprise Linux 4 (AS/ES) is on /proc/scsi/qla2xxx/1 (1,2,3,..N)
Sample:

# egrep [node|port] /proc/scsi/qlx2xxx/0
scsi-qla0-adapter-node=200000e08b1c19f2;
scsi-qla0-adapter-port=210000e08b1c19f2;

for Emulex /proc/scsi/lpexxx/1 (1,2,3,..N)