redhat linux 9.0 安装了libpcap，编译程序时却总是出错！

[fantasy89f]

libpacp安装时没有提示错误，编译程序时提示如下：
[root@redhat project]# gcc -Wall -o 123 sniffex.c
/tmp/cc6MG2NA.o(.text+0x546): In function `main':
: undefined reference to `pcap_lookupdev'
/tmp/cc6MG2NA.o(.text+0x596): In function `main':
: undefined reference to `pcap_lookupnet'
/tmp/cc6MG2NA.o(.text+0x62d): In function `main':
: undefined reference to `pcap_open_live'
/tmp/cc6MG2NA.o(.text+0x674): In function `main':
: undefined reference to `pcap_datalink'
/tmp/cc6MG2NA.o(.text+0x6c3): In function `main':
: undefined reference to `pcap_compile'
/tmp/cc6MG2NA.o(.text+0x6d9): In function `main':
: undefined reference to `pcap_geterr'
/tmp/cc6MG2NA.o(.text+0x716): In function `main':
: undefined reference to `pcap_setfilter'
/tmp/cc6MG2NA.o(.text+0x72c): In function `main':
: undefined reference to `pcap_geterr'
/tmp/cc6MG2NA.o(.text+0x76c): In function `main':
: undefined reference to `pcap_loop'
/tmp/cc6MG2NA.o(.text+0x77e): In function `main':
: undefined reference to `pcap_freecode'
/tmp/cc6MG2NA.o(.text+0x78f): In function `main':
: undefined reference to `pcap_close'
collect2: ld returned 1 exit status

应该是找不到库函数的问题，但是我在centOS下按一样的流程进行却能编译成功，哪里出问题了吗？
还有我指定了C_INCLUDE_PATH和LIBRARY_PATH以后问题依旧

[Wenxy1]

是编译成功，链接失败，检查你的libpcap库path是否设置对了。

[fantasy89f]

[Quote=引用 1 楼 wenxy1 的回复:]
是编译成功，链接失败，检查你的libpcap库path是否设置对了。
[/Quote]
请问我该如何检查libpcap的库path是否设置正确呢？