linux grep命令操作指南

          ① 定義
         
             grep是行級裝置，它分析一行資訊，若當中有我們所需要的資訊，就將整行返回
            
          ② 作用
         
             進行字串資料的對比，將符合使用者需求的字串列印出來
            
          ③ 格式
         
             grep [-acinv] [--color=auto] '尋找字串' filename
            
             參數：
             -a：將二進位檔案一text檔案的方式尋找資料
             -c：計算找到‘尋找字串’的次數
             -i：對大小寫透明
             -n：輸出行號
             -v：顯示沒有‘尋找字串’內容的那一行
             -A:後面可加數字，為after的意思，除了列出該行外，後續的n行也列出來
             -B:後面可加數字，為before的意思，除了列出該行外，前面的n行也列出來
             --color=auto：關鍵字上色

          ④ 例子
             eg01：找出有檢查點事件發生的標誌

[oracle@localhost bdump]$ grep -in --color=auto 'checkpoint' alert_orcl.log64:  checkpoint is 44607466:  checkpoint is 44607469:  checkpoint is 44607472:  checkpoint is 446074383:  checkpoint is 4602001845:Checkpoint not complete2112:  checkpoint is 6062172114:  checkpoint is 6062172116:  checkpoint is 6062172118:  checkpoint is 6062172120:  checkpoint is 606217

            eg02：從核心中找出網卡相關資訊

[oracle@localhost bdump]$ dmesg | grep -n -A3 -B2 --color=auto 'eth'599-iscsi: registered transport (iser)600-iscsi: registered transport (be2iscsi)601:eth0: no IPv6 routers present602-Bluetooth: Core ver 2.10603-NET: Registered protocol family 31604-Bluetooth: HCI device and connection manager initialized--615-ip_conntrack version 2.4 (8192 buckets, 65536 max) - 228 bytes per conntrack616-ip6_tables: (C) 2000-2006 Netfilter Core Team617:peth0: Promiscuous mode enabled.618:device peth0 entered promiscuous mode619:xenbr0: port 1(peth0) entering forwarding state620-device vif0.0 entered promiscuous mode621-New device vif0.0 does not support netpoll622-Disabling netpoll for xenbr0--625-hdc: drive_cmd: error=0x04 { AbortedCommand }626-ide: failed opcode was: 0xec627:eth0: no IPv6 routers present628:xenbr0: port 1(peth0) entering disabled state629:xenbr0: port 1(peth0) entering forwarding state