Remove all duplicate word from string using shell script

Question

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

Solution 1

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

Solution 2

With tr, sort and uniq

echo "zebra ant spider spider ant zebra ant" | tr ' ' '\n' | sort -u

or

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

to get one line

Solution 3

$ echo "zebra ant spider spider ant zebra ant"  | awk -v RS="[ \n]+" '!n[$0]++' 
zebra
ant
spider

Solution 4

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.

Solution 5

perl -lane '$,=$";print grep { ! $h{$_}++ } @F'

View more solutions

Comments

[terdon]

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?

[Sundeep]

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

[Urvashi]

string value comes dynamically. It is printing same value (contain duplicate value).

[Sundeep]

yeah, show the code that failed, otherwise how would we know what could've gone wrong?

[Jacob Vlijm]

Does the order matter?

[Urvashi]

@JacobVlijm yes order matter.I updated my question so you can easily understand.

[Urvashi]

@Sundeep i updated my answer please see.

[Sundeep]

@Urvashi your string uses , as delimiter while the code you found worked on space as delimiter... why do you expect it to work on your string? all answers attempted will now be invalidated because of that

[Sundeep]

again we cannot debug code which you don't show, also your expected output "red,black,blue,red,green," has red repeated... and , at end of string is required?

[Urvashi]

@Sundeep red,black,blue,green" this is desired ,It was typing mistake.I corrected.

[Sundeep]

try a simple awk + paste command instead of shell scripting, awk '$1=="AAA" {if(!seen[$3]++) print $3}' input.txt | paste -sd, where you need to replace input.txt with name of your file

[Urvashi]

Let us continue this discussion in chat.

[Philippos]

You need to add | xargs to join the output to one line again

[George Vasiliou]

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.

[ilkkachu]

Yes, they will be printed in an essentially random order. The sort solution doesn't keep the original order either, though.

[George Vasiliou]

Yes, good point! Even sort prints in different order than input.

[Andrew Carsell]

@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.

[Benoît]

Or use sort -u. Or even a awk '!u[$0]++.

[someonewithpc]

What are \< and \>?

[Philippos]

@someonewithpc They match no character, but the beginning and end of a word to prevent substrings from being matched.

[someonewithpc]

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.

[Philippos]

@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

[George Vasiliou]

Very clever!!!!

[gardenhead]

@Benoît Wow, I did not know about sort -u. I've been using sort | uniq all this time. The wasted keystrokes...

[xhienne]

Please add an explanation on how your code works and why you did this and that.

[JJoao]

@GeorgeVasiliou, thank you [or to tell the truth, very lazy :-) ]

[Pierre.Vriens]

I do not get it

[JeremyCanfield]

Neat approach. The only adjustment I had to make was to use %s instead of %s%s. The reason being is that I was doing a for loop through the results and two white spaces caused some challenges with regex matches.

[Kusalananda]

Your code lack explanation. With no explanation, it's difficult to follow what's happening. You also seem to make assumptions about the data that seems wrong (whitespace-delimited fields) and about the particular awk implementation being used (asorti() is not a standard awk function).

[xeruf]

what if there are other word separators, such as dots, involved?