#LeetCode# Tenth Line

How would you print just the 10th line of a file?

For example, assume that file.txt has the following content:

Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10

Your script should output the tenth line, which is:

Line 10

三种方法。

1.AWK，我也只会这一种，后边俩是谷歌来的

awk "NR == 10" file.txt

这里的NR就是number of rows的意思，即第几行

2.SED

sed -n '10p' file.txt

3.Tail and Head

NR = ' cat file.txt | wc -1 '
if [ $NR -ge 10 ] ; then
   tail -n +10 file.txt | head -1
fi

加入if...fi条件语句，先判断文件是否超出10行

tail从第十行开始执行，输出重定向为head，head提取此时的第一行，正好是文件的第十行。

LOL