Delete Line If Next Line Is the Same – Text Processing Guide

awksedtext processing

What sed/awk command can I use? Just sort -u will remove all instances

Input:

abc
abc
def
abc
abc
def

Expected output:

abc
def
abc
def

Best Answer

That's what the uniq standard command is for.

uniq your-file

Note that some uniq implementations like GNU uniq will give you the first of a sequence of lines that sort the same (where strcoll() returns 0) as opposed to are byte-to-byte identical (where memcmp() or strcmp() returns 0). To force a byte to byte comparison regardless of the uniq implementation, you can force the locale to C with:

LC_ALL=C uniq your-file

Solution 1

$ echo abc,10.11.13.14,def,1.2.3.4,geh,6.7.54.23 | awk -F, '{for (i=1; i<NF; i+=2) if ($i == "def") print $(i+1)}'
1.2.3.4

In this case, I am looking for a machine name "def", if found, print the next column.

Solution 2

$ echo abc,10.11.13.14,def,1.2.3.4,geh,6.7.54.23 | tr , \\n | awk '/def/ {getline;print}'
1.2.3.4

In this solution, I use the tr command to convert commas to new line, search for "def" and print the line that follows. I hope these solutions work for you.

Delete lines containing repeated text

awk '{ if ($1 != $2 ) print $1" "$2; }' file

Just replace file for the appropriate file.

Or as @manatwork mentioned in the comments and simpler

awk '$1!=$2' file

Best Answer

Related Solutions

Grep device name and look for next value :

Solution 1

Solution 2

Delete lines containing repeated text

Related Question