up vote 5 down vote favorite
1

I have a string like 

"aaa,aaa,aaa,bbb,bbb,ccc,bbb,ccc"

I want to remove duplicate word from string then output will be like 

"aaa,bbb,ccc"

I tried This code Source

$ echo "zebra ant spider spider ant zebra ant" | xargs -n1 | sort -u | xargs

It is working fine with same value,but when I give my variable value then it is showing all duplicate word also.

How can I remove duplicate value.

UPDATE

My question is adding all corresponding value into a single string if user is same .I have data like this ->

   user name    | colour
    AAA         | red
    AAA         | black
    BBB         | red
    BBB         | blue
    AAA         | blue
    AAA         | red
    CCC         | red
    CCC         | red
    AAA         | green
    AAA         | red
    AAA         | black
    BBB         | red
    BBB         | blue
    AAA         | blue
    AAA         | red
    CCC         | red
    CCC         | red
    AAA         | green

In coding I fetch all distinct user then I concatenate color string successfully .For that I am using code -

while read the records 

    if [ "$c" == "" ]; then  #$c I defined global
        c="$colour1"
    else
        c="$c,$colour1" 
    fi

When I print this $c variable i get the output (For User AAA) 

"red,black,blue,red,green,red,black,blue,red,green,"

I want to remove duplicate color .Then desired output should be like

"red,black,blue,green"

For this desired output i used above code 

 echo "zebra ant spider spider ant zebra ant" | xargs -n1 | sort -u | xargs

but it is displaying the output with duplicate values .Like

"red,black,blue,red,green,red,black,blue,red,green," Thanks

share|improve this question
3  
Please clarify what is wrong with what you are using. I don't understand what you mean by "when I give my variable value". What value do you give? Where does it fail? – terdon♦ yesterday
    
echo 'aaa aaa aaa bbb bbb ccc bbb ccc' | xargs -n1 | sort -u | xargs gives aaa bbb ccc.. so you need to show exact code you tired and output you got.. with the string in variable: s='aaa aaa aaa bbb bbb ccc bbb ccc'; echo "$s" | xargs -n1 | sort -u | xargs – Sundeep yesterday
    
string value comes dynamically. It is printing same value (contain duplicate value). – Urvashi yesterday
1  
yeah, show the code that failed, otherwise how would we know what could've gone wrong? – Sundeep yesterday
    
Does the order matter? – Jacob Vlijm yesterday
up vote 3 down vote accepted

One more awk, just for fun:

$ a="aaa bbb aaa bbb ccc aaa ddd bbb ccc"
$ echo "$a" | awk '{for (i=1;i<=NF;i++) if (!a[$i]++) printf("%s%s",$i,FS)}{printf("\n")}'
aaa bbb ccc ddd

By the way, even your solution works fine with variables:

$ b="zebra ant spider spider ant zebra ant" 
$ echo "$b" | xargs -n1 | sort -u | xargs
ant spider zebra
share|improve this answer
    
This works for me .Thanks @George Vasiliou – Urvashi yesterday
up vote 8 down vote 
$ echo "zebra ant spider spider ant zebra ant"  | awk -v RS="[ \n]+" '!n[$0]++' 
zebra
ant
spider
share|improve this answer
1  
Very clever!!!! – George Vasiliou yesterday
    
@GeorgeVasiliou, thank you [or to tell the truth, very lazy :-) ] – JJoao yesterday
up vote 6 down vote

With tr, sort and uniq

echo "zebra ant spider spider ant zebra ant" | tr ' ' '\n' | sort | uniq

or 

echo "zebra ant spider spider ant zebra ant" | tr ' ' '\n' | sort | uniq | xargs

to get one line

share|improve this answer
    
You need to add | xargs to join the output to one line again – Philippos yesterday
    
thanks, updated my answer – Michael D. yesterday
3  
Or use sort -u. Or even a awk '!u[$0]++. – Benoît yesterday
1  
@Benoît Wow, I did not know about sort -u. I've been using sort | uniq all this time. The wasted keystrokes... – gardenhead yesterday
up vote 2 down vote

With gnu sed:

sed ':s;s/\(\<\S*\>\)\(.*\)\<\1\>/\1\2/g;ts'

You may add ;s/ */ /g to remove dublicate spaces.

Functions like this: If a word is a second time in this line, remove it and start over until no dublication is found anymore.

share|improve this answer
    
What are \< and \>? – someonewithpc yesterday
    
@someonewithpc They match no character, but the beginning and end of a word to prevent substrings from being matched. – Philippos yesterday
    
Nice, but is that portable? Also, aren't words separated by whitespace? Seems redundant to match not whitespace followed by the end of a word. – someonewithpc yesterday
1  
@someonewithpc No, it's not standard, that's why I wrote gnu sed. The nice part is that you don't have to handle first and last string separately – Philippos yesterday
up vote 2 down vote 
perl -lane '$,=$";print grep { ! $h{$_}++ } @F'
share|improve this answer
up vote 2 down vote

Obligatory awk solution:

$ echo "ant zebra ant spider spider ant zebra ant" | 
   awk -vRS=" " -vORS=" " '!a[$1] {a[$1]++} END{ for (x in a) print x;  } ' ; echo
zebra ant spider

(The final echo is there for the newline)

share|improve this answer
    
Plus one for the awk ! I was builting also an awk solution just for fun. There is a slight possibility words to be printed in random order at END section due to the random way that awk itterates in array keys. – George Vasiliou yesterday
    
Yes, they will be printed in an essentially random order. The sort solution doesn't keep the original order either, though. – ilkkachu yesterday
    
Yes, good point! Even sort prints in different order than input. – George Vasiliou yesterday
    
@ilkkachu Actually we don't need to wait for the input to end. We can make decision to print or not to print with a slight modification to your code: awk -vRS=" " -vORS=" " '!a[$1]++ {print $1}' ; echo This preserves the order. – Rakesh Sharma yesterday
up vote 1 down vote

Python

#!/usr/bin/python
# get_unique_words.py

import sys

l = []
for w in sys.argv[1].split():
  if w not in l:
     l += [ w ]
print ' '.join(l)

Make executable, then call from Bash:

$ ./get_unique_words.py "aaa aaa aaa bbb bbb ccc bbb ccc"
aaa bbb ccc
$ ./get_unique_words.py "zebra ant spider spider ant zebra ant"
zebra ant spider
share|improve this answer
up vote -2 down vote 
a="aaa aaa aaa bbb bbb ccc bbb ccc"
for item in $a
do
   echo $item
done | sort -u | (while read i; do ans="$ans $i"; done ; echo $ans)
share|improve this answer
    
Please add an explanation on how your code works and why you did this and that. – xhienne yesterday

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