tail命令用於輸入文件中的尾部內容。tail命令默認在屏幕上顯示指定文件的末尾10行。 如果給定的文件不止一個，則在顯示的每個文件前面加一個文件名標題。
[b] (1)用法:[/b] 用法: tail [必要參數] [選擇參數] [文件]
如果沒有指定文件或者文件名為“-”，則讀取標准輸入。[b] (2)功能:[/b]
功能: 輸出文件的末尾部分[b] (3)選項參數:[/b]
1) -n <k行數> 顯示文件末尾k行內容 2) -c <k字節數> 顯示文件末尾k個字節數
3) -f 循環讀取 4) -q 不顯示處理信息
5) -v 顯示詳細的處理信息[b] (4)實例:[/b]
1)[root@localhost Documents]# tail -n 5 ./tail_text 查看文件後5行的內容
[root@localhost Documents]# cat tail_text > 01 the first line! > 02 the second line! > 03 the third line! > 04 the forth line! > 05 the fifth line! > 06 the sixth line! > o7 the seventh line! > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line! [root@localhost Documents]# tail -n 5 ./tail_text > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line!
等價於tail -5 text_tail 查看後5行的內容
[root@localhost Documents]# tail -5 tail_text > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line!
2)[root@localhost Documents]# tail -n +5 tail_text 從第5行開始顯示
[root@localhost Documents]# tail -n +5 tail_text > 05 the fifth line! > 06 the sixth line! > o7 the seventh line! > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line!
3)[root@localhost Documents]# head -n -5 tail_text與[root@localhost Documents]# tail -n -5 tail_text
[root@localhost Documents]# head -n 5 tail_text //顯示文件前5行的內容 > 01 the first line! > 02 the second line! > 03 the third line! > 04 the forth line! > 05 the fifth line! [root@localhost Documents]# head -n -5 tail_text //除了文件後五行全部顯示 > 01 the first line! > 02 the second line! > 03 the third line! > 04 the forth line! > 05 the fifth line! > 06 the sixth line! > o7 the seventh line! //head命令的-n參數，當後面的整數為正為負是有區別的 [root@localhost Documents]# tail -n 5 tail_text //tail命令的-n參數，當後面的整數為正為負是一樣的 > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line! [root@localhost Documents]# tail -n -5 tail_text //都是顯示末尾的整數的絕對值行 > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line!
4)[root@localhost Documents]# tail -c 30 tail_text 顯示末尾的字節數
[root@localhost Documents]# tail -c 30 tail_text n line! > 12 the twelve line! [root@localhost Documents]# tail -c -30 tail_text n line! > 12 the twelve line! [root@localhost Documents]# head -c 30 tail_text > 01 the first line! > 02 the [root@localhost Documents]# head -c -30 tail_text > 01 the first line! > 02 the second line! > 03 the third line! > 04 the forth line! > 05 the fifth line! > 06 the sixth line! > o7 the seventh line! > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleve[root@localhost Documents]#
5)[root@localhost Documents]# tail -f tail_text 循環讀取內容輸出到標准輸出
[root@localhost Documents]# tail -f tail_text //默認是後10行 > 03 the third line! > 04 the forth line! > 05 the fifth line! > 06 the sixth line! > o7 the seventh line! > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line! ^C [root@localhost Documents]# tail -f -n 12 tail_text //也可以自己指定 > 01 the first line! > 02 the second line! > 03 the third line! > 04 the forth line! > 05 the fifth line! > 06 the sixth line! > o7 the seventh line! > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line! ^Z [6]+ 已停止 tail -f -n 12 tail_text [root@localhost Documents]# tail -f -n 7 tail_text > 06 the sixth line! > o7 the seventh line! > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line!
當然，也可以把信息輸入到文件中:
[root@localhost Documents]# tail -f tail_text>tempory ^Z [9]+ 已停止 tail -f tail_text > tempory [root@localhost Documents]# cat tempory > 03 the third line! > 04 the forth line! > 05 the fifth line! > 06 the sixth line! > o7 the seventh line! > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line!
6)[root@localhost Documents]# tail -n +5 tail_text與[root@localhost Documents]# tail -n 5 tail_text
[root@localhost Documents]# tail -n +5 tail_text > 05 the fifth line! > 06 the sixth line! > o7 the seventh line! > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! > 11 the eleven line! > 12 the twelve line![root@localhost Documents]# tail -n 5 tail_text
> 08 the eighth line!
> 09 the nineth line!
> 10 the tenth line!
> 11 the eleven line!
> 12 the twelve line!
[root@localhost Documents]# head -n +5 tail_text
> 01 the first line!
> 02 the second line!
> 03 the third line!
> 04 the forth line!
> 05 the fifth line!
[root@localhost Documents]# head -n 5 tail_text
> 01 the first line!
> 02 the second line!
> 03 the third line!
> 04 the forth line!> 05 the fifth line!
7)[root@localhost Documents]# tail -n +10 tail_text |head -n -2
[root@localhost Documents]# tail -n +10 tail_text //從第10行顯示到尾部 > 10 the tenth line! > 11 the eleven line! > 12 the twelve line! [root@localhost Documents]# head -n -2 tail_text //除了末尾兩行之外前面的都顯示 > 01 the first line! > 02 the second line! > 03 the third line! > 04 the forth line! > 05 the fifth line! > 06 the sixth line! > o7 the seventh line! > 08 the eighth line! > 09 the nineth line! > 10 the tenth line! [root@localhost Documents]# tail -n +10 tail_text |head -n -2 //綜合起來，用管道命令就是後一個命令處理前面的結果，因此達到只顯示第10行的效果 > 10 the tenth line! [root@localhost Documents]#