Grepping all strings on the same line from multiple files - awk

Question

Trying to find a way to grep all names on one line for 100 files. grepping all names available in each file must appear on the same line.
FILE1
"company":"COMPANY1","companyDisplayName":"CM1","company":"COMPANY2","companyDisplayName":"CM2","company":"COMPANY3","companyDisplayName":"CM3",
FILE2
"company":"COMPANY99","companyDisplayName":"CM99"
The output i actually want is, ( include file name as prefix.)
FILE1:COMPANY1,COMPANY2,COMPANY3
FILE2:COMPANY99
i tried grep -oP '(?<="company":")[^"]*' * but i get results like this :
FILE1:COMPANY1
FILE1:COMPANY2
FILE1:COMPANY3
FILE2:COMPANY99

Answer 1

Could you please try following.
awk -F'[,:]' '
BEGIN{
OFS=","
}
{
for(i=1;i<=NF;i++){
if($i=="\"company\""){
val=(val?val OFS:"")$(i+1)
}
}
gsub(/\"/,"",val)
print FILENAME":"val
val=""
}
' Input_file1 Input_file2
Explanation: Adding explanation for above code.
awk -F'[,:]' ' ##Starting awk program here and setting field separator as colon OR comma here for all lines of Input_file(s).
BEGIN{ ##Starting BEGIN section of awk here.
OFS="," ##Setting OFS as comma here.
} ##Closing BEGIN BLOCK here.
{ ##Starting main BLOCK here.
for(i=1;i<=NF;i++){ ##Starting a for loop which starts from i=1 to till value of NF.
if($i=="\"company\""){ ##Checking condition if field value is equal to "company" then do following.
val=(val?val OFS:"")$(i+1) ##Creating a variable named val and concatenating its own value to it each time cursor comes here.
} ##Closing BLOCK for if condition here.
} ##Closing BLOCK for, for loop here.
gsub(/\"/,"",val) ##Using gsub to gklobally substitute all " in variable val here.
print FILENAME":"val ##Printing filename colon and variable val here.
val="" ##Nullifying variable val here.
} ##Closing main BLOCK here.
' Input_file1 Input_file2 ##Mentioning Input_file names here.
Output will be as follows.
Input_file1:COMPANY1,COMPANY2,COMPANY3
Input_file2:COMPANY99
EDIT: Adding solution in case OP needs to use grep and want to get final output from its output(though I will recommend to use awk solution itself since we are NOT using multiple commands or sub-shells).
grep -oP '(?<="company":")[^"]*' * | awk 'BEGIN{FS=":";OFS=","} prev!=$1 && val{print prev":"val;val=""} {val=(val?val OFS:"")$2;prev=$1} END{if(val){print prev":"val}}'

Answer 2

There are two tools that can take the output of your grep command and reformat it the way you want. First tool is GNU datamash. Second is tsv-summarize from eBay's tsv-utils package (disclaimer: I'm the author). Both tools solve this in similar ways:
$ # The grep output
$ echo $'FILE1:COMPANY1\nFILE1:COMPANY2\nFILE1:COMPANY3\nFILE2:COMPANY99' > grep-output.txt
$ cat grep-output.txt
FILE1:COMPANY1
FILE1:COMPANY2
FILE1:COMPANY3
FILE2:COMPANY99
$ # Using GNU datamash
$ cat grep-output.txt | datamash -field-separator : --group 1 unique 2
FILE1:COMPANY1,COMPANY2,COMPANY3
FILE2:COMPANY99
$ # Using tsv-summarize
$ cat grep-output.txt | tsv-summarize --delimiter : --group-by 1 --unique-values 2 --values-delimiter ,
FILE1:COMPANY1,COMPANY2,COMPANY3
FILE2:COMPANY99