詳解Linux系統(tǒng)中字符串搜索命令ngrep的用法

ngrep 是grep的網(wǎng)絡版，他力求更多的grep特征，用于搜尋指定的數(shù)據(jù)包。由于安裝ngrep需用到ibpcap庫， 所以支持大量的操作系統(tǒng)和網(wǎng)絡協(xié)議，能識別TCP、UDP和ICMP包。

安裝ngrep
下載地址

選項

-h     is help/usage
-V    is version information
-q    is be quiet (don't print packet reception hash marks)靜默模式，如果沒有此開關，未匹配的數(shù)據(jù)包都以“#”顯示
-e    is show empty packets 顯示空數(shù)據(jù)包
-i     is ignore case 忽略大小寫
-v    is invert match 反轉匹配
-R   is don't do privilege revocation logic
-x    is print in alternate hexdump format 以16進制格式顯示
-X   is interpret match expression as hexadecimal 以16進制格式匹配
-w   is word-regex (expression must match as a word) 整字匹配
-p   is don't go into promiscuous mode 不使用混雜模式
-l     is make stdout line buffered
-D   is replay pcap_dumps with their recorded time intervals
-t     is print timestamp every time a packet is matched在每個匹配的包之前顯示時間戳
-T    is print delta timestamp every time a packet is matched顯示上一個匹配的數(shù)據(jù)包之間的時間間隔
-M   is don't do multi-line match (do single-line match instead)僅進行單行匹配
-I     is read packet stream from pcap format file pcap_dump 從文件中讀取數(shù)據(jù)進行匹配
-O   is dump matched packets in pcap format to pcap_dump 將匹配的數(shù)據(jù)保存到文件
-n    is look at only num packets 僅捕獲指定數(shù)目的數(shù)據(jù)包進行查看
-A   is dump num packets after a match匹配到數(shù)據(jù)包后Dump隨后的指定數(shù)目的數(shù)據(jù)包
-s    is set the bpf caplen
-S   is set the limitlen on matched packets
-W  is set the dump format (normal, byline, single, none) 設置顯示格式byline將解析包中的換行符
-c    is force the column width to the specified size 強制顯示列的寬度
-P   is set the non-printable display char to what is specified
-F   is read the bpf filter from the specified file 使用文件中定義的bpf(Berkeley Packet Filter)
-N   is show sub protocol number 顯示由IANA定義的子協(xié)議號
-d   is use specified device (index) instead of the pcap default

應用舉例：

捕獲所有post請求(加個-W byline 參數(shù)后,將解析包中的換行符)：