LeetCode

LeetCode - Easy - 195. Tenth Line

Topic

• Bash

Description

https://leetcode.com/problems/tenth-line/

Given a text file file.txt, print just the 10th line of the file.

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

Note:

1. If the file contains less than 10 lines, what should you output?
2. There's at least three different solutions. Try to explore all possibilities.

Analysis

1. awk 是一种处理文本文件的语言，是一个强大的文本分析工具。
2. sed 可依照脚本的指令来处理、编辑文本文件。
3. tail 命令可用于查看文件的内容

Submission

# Solution 1
cnt=0
while read line && [ $cnt -le 10 ]; do
  let 'cnt = cnt + 1'
  if [ $cnt -eq 10 ]; then
    echo $line
    exit 0
  fi
done < file.txt

# Solution 2
awk 'FNR == 10 {print }'  file.txt
# OR
awk 'NR == 10' file.txt

# Solution 3
sed -n 10p file.txt

# Solution 4
tail -n+10 file.txt|head -1

Test

略

来源：oschina

链接：https://my.oschina.net/jallenkwong/blog/4838147