Extract substrings from each line. These substrings are in comma separated, "name=value" format

Question

I have lines in a file that are comma separated. There are no column headers, it's mostly comma separated 'name=value' pairs. Here is some test data:

listoffruits,producelist,APPLE=red,BANNANA=yellow,GRAPE=purple,ORANGE=orange,FRUIT=yes,WATERMELON=green
listoffruits,producelist,APPLE=red,BANNANA=yellow,GRAPE=violet,ORANGE=orange,FRUIT=affirmative,WATERMELON=green

I would like to get the value for GRAPE=* and FRUIT=* to get the result:

purple yes
violet affirmative

Also I would like the ability to add more "columns" later (so not always GRAPE, FRUIT, but GRAPE, FRUIT and WATERMELON)

Another snag is the columns are not fixed. So I don't always know that WATERMELON is the last column.

The closest I got was from @jasonwryan:

awk -v RS="," -F= '/GRAPE/{a=$2}; /FRUIT/{b=$2} END{print a,b"\n"}'

but this outputs the last line "violet affirmative" and not:

purple yes

violet affirmative

Answer 1

Some more choices. I have saved your example text in file for simplicity.

1. grep and PCREs:

   $ grep -oP '(GRAPE|FRUIT)=\K.*?(?=,)' file 
   purple
   yes
   violet
   affirmative
   

   To get them on the same line, just parse. For example

   $ grep -oP '(GRAPE|FRUIT)=\K.*?(?=,)' | paste -d" " - - –  
   purple yes
   violet affirmative
   

2. sed

   $ sed 's/.*GRAPE=\([^,]*\).*FRUIT=\([^,]*\).*/\1 \2/' file 
   purple yes
   violet affirmative
   

   Or, with GNU sed

   $ sed -r 's/.*GRAPE=([^,]*).*FRUIT=([^,]*).*/\1 \2/' file 
   purple yes
   violet affirmative
   

3. Perl

   $ perl -pne 's/.*GRAPE=([^,]*).*FRUIT=([^,]*).*/\1 \2/' file 
   purple yes
   

   You might notice the above is slightly similar to the sed one :). Alternatively:

   $ perl -lne '@f=(/(?:(?<=GRAPE=)|(?<=FRUIT=))(.+?),/g); print "@f"' file 
   purple yes
   violet affirmative
   

   This uses , as a field separator and searches all fields:

   $ perl -F, -lane '@r=grep(s/.+?=//, grep(/GRAPE|FRUIT/,@F)); print "@r"' file 
   purple yes
   violet affirmative
   

   This one is shorter but adds a leading space to each line:

   $ perl -F, -lane 'print grep(s/.+?=/ /, grep(/GRAPE|FRUIT/,@F));' file 
    purple yes
    violet affirmative
   

Answer 2

Using Awk:

awk -v RS="," -F= '/GRAPE/||/FRUIT/ {printf "%s ", $2}'

Changes the record separator from a new line to , and the field separator from a space to a =, then match lines that contain the pattern GRAPE or FRUIT and print the second matching field on the same line separated by a space. Result:

purple yes