如何打印筛选出某列相同的相邻两行?

mygod100

有文本如下
99 line0
100 line1
100 line2
101 line3
102 line4
103 line5
103 line6


如何将首列相同的相邻行筛选出，能到到如下结果
100 line1
100 line2
103 line5
103 line6

谢谢！

rdcwayx

1. awk 'NR==FNR{a[$1]++;next} a[$1]>1 ' infile infile

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关阴月飞

回复 1# mygod100

1. awk '$1==a{print c[$1]==1?b"\n"$0:$0}{a=$1;b=$0;c[$1]++}'  urfile

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li0924

1. awk '{a[NR]=$1;b[NR]=$0}END{for(i=1;i<=NR;i++){if(a[i]==a[i+1])print b[i]"\n"b[i+1]}}'

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reyleon

1. awk '{a[$1]++;b[$1]=b[$1]?b[$1]"\n"$0:$0}END{for(i in a)if(a[i]>1)print b[i]}'

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jason680

回复 1# mygod100

How about this one

# awk '$1==S1{print S0;do{print $0;getline}while(S1==$1);}{S1=$1;S0=$0}' dup.txt
100 line1
100 line11
100 line2
103 line5
103 line55
103 line6

# cat dup.txt
99 line0
100 line1
100 line11
100 line2
101 line3
102 line4
103 line5
103 line55
103 line6
104 line7

   

LikeLx

回复 6# jason680

我用你的代码getline时 结果一直输出，改成next才能显示正常结果，[root@dbserver ~]# awk '$1==S1{print S0;do{print $0;next}while(S1==$1);}{S1=$1;S0=$0}' test1.sh
100 line1
100 line2
103 line5
103 line6
103 line5

[root@dbserver ~]# awk --version
GNU Awk 3.1.5
Copyright (C) 1989, 1991-2005 Free Software Foundation.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.