求如何打印任意文本正中间行

mswsg

python get_middle_line.py your_file

1. #!/usr/bin/env python
   
2. # -*- coding: utf-8 -*-
   
3. __author__ = 'shengwei ma'
   
4. '''http://bbs.chinaunix.net/thread-4243379-1-1.html'''
   
5. 
   
6. import os
   
7. import sys
   
8. 
   
9. input1 = os.path.abspath(sys.argv[1])
   
10. with open(input1, 'r') as f:
    
11.     lines = f.readlines()
    
12.     print lines
    
13.     total_lines = len(lines)
    
14.     if total_lines % 2 == 0:
    
15.         print lines[int(total_lines / 2 - 1)] + lines[int(total_lines / 2)]
    
16.     else:
    
17.         print lines[int(total_lines / 2)]

复制代码

zy86416779

1. #!/bin/sh
   
2. Line=$(wc -l $1|awk '{print $1}')
   
3. if [ $(($Line % 2)) -eq 0 ];then
   
4.   head -n $(($Line/2+1)) $1 | tail -n 2
   
5. else
   
6.   head -n $((`expr $Line + 1`/2)) $1 | tail -n 1
   
7. fi

复制代码

tolilong

cat tt2 | tr "\n" " " | awk 'NF%2==0{print $(NF/2),$(NF/2+1)}NF%2!=0{print $(NF/2+1)}' | tr " " "\n"

这样应该可以吧,试试

toddhai

awk '{a[NR]=$2;}END{if(NR%2)print a[(NR+1)/2];else print a[NR/2]"\n"a[NR/2+1]}' urfile

oldknew

#!/bin/bash
cp $1 1.txt
while [ true ]
do
    linenum=`sed -n '$=' 1.txt`
    if [ $linenum -lt 3 ]
    then
    break
    fi
    sed -i '1d;$d' 1.txt
done
cat 1.txt