10

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

  • 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 Mar 23 '17 at 12:57
  • 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 Mar 23 '17 at 13:01
  • string value comes dynamically. It is printing same value (contain duplicate value). – Urvashi Mar 23 '17 at 13:02
  • 1
    yeah, show the code that failed, otherwise how would we know what could've gone wrong? – Sundeep Mar 23 '17 at 13:02
  • Does the order matter? – Jacob Vlijm Mar 23 '17 at 14:06

10 Answers 10

11

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
  • 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. – JeremyCanfield Mar 20 at 4:37
8
$ echo "zebra ant spider spider ant zebra ant"  | awk -v RS="[ \n]+" '!n[$0]++' 
zebra
ant
spider
  • 1
    Very clever!!!! – George Vasiliou Mar 24 '17 at 0:54
  • @GeorgeVasiliou, thank you [or to tell the truth, very lazy :-) ] – JJoao Mar 24 '17 at 8:44
7

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

  • You need to add | xargs to join the output to one line again – Philippos Mar 23 '17 at 12:59
  • 3
    Or use sort -u. Or even a awk '!u[$0]++. – Benoît Mar 23 '17 at 18:42
  • 1
    @Benoît Wow, I did not know about sort -u. I've been using sort | uniq all this time. The wasted keystrokes... – gardenhead Mar 24 '17 at 1:25
2

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.

  • What are \< and \>? – someonewithpc Mar 23 '17 at 20:19
  • @someonewithpc They match no character, but the beginning and end of a word to prevent substrings from being matched. – Philippos Mar 23 '17 at 21:29
  • 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 Mar 23 '17 at 21:34
  • 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 Mar 23 '17 at 21:44
2
perl -lane '$,=$";print grep { ! $h{$_}++ } @F'
2

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)

  • 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 Mar 23 '17 at 14:14
  • Yes, they will be printed in an essentially random order. The sort solution doesn't keep the original order either, though. – ilkkachu Mar 23 '17 at 14:17
  • Yes, good point! Even sort prints in different order than input. – George Vasiliou Mar 23 '17 at 14:18
  • 1
    @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. – user218374 Mar 23 '17 at 14:31
1

Python

Option 1

#!/usr/bin/env 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

Or you could implement it as a Bash function, but the syntax is messy.

get_unique_words(){
  python -c "
l = []
for w in '$1'.split(','):
  if w not in l:
    l += [ w ]
print ','.join(l)"
}

Option 2

This option can become a one-liner if needed:

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

import sys

s_in = sys.argv[1]
l_in = s_in.split(',') # Turn string into a list.
set_out = set(l_in) # Turning a list into a set removes duplicates items.
s_out = ','.join(set_out) 
print s_out

In Bash:

get_unique_words(){
  python -c "print ','.join(set('$1'.split(',')))"
}
0
cat filename | awk '{ delete a; for (i=1; i<=NF; i++) a[$i]++; n=asorti(a, b); for (i=1; i<=n; i++) printf b[i]" "; print "" }' > newfile
  • I do not get it – Pierre.Vriens Dec 2 '18 at 7:00
  • 1
    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). – Kusalananda Mar 20 at 21:15
0

Using the original tabular data in the file called file:

sed '1d' file | sort -u |
awk '{ color[$1] = ( color[$1] == "" ? $3 : color[$1] "," $3 ) }
     END { for (user in color) print user, color[user] }'

This generates

CCC red
BBB blue,red
AAA black,blue,green,red

The three steps of the pipeline:

  1. The sed command removes the first line which is a header that we don't want to read.
  2. The sort command gives us unique lines. The sample data after the sort looks like

    AAA         | black
    AAA         | blue
    AAA         | green
    AAA         | red
    BBB         | blue
    BBB         | red
    CCC         | red
    
  3. The awk command takes this data and produces a comma-delimited string for each user in the array color (where the username is the key into the array). At the end (in the END block), all collected data is outputted.
-2
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)
  • Please add an explanation on how your code works and why you did this and that. – xhienne Mar 24 '17 at 1:37

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