Shell Programming and Scripting

perldoc -f chomp

Barcode;Sku;Fabrikant
123, 456, 567;microsoftnatural;Microsoft
123456789;testnderp;Acer
1230000000001;ND001;TestMerk
1230000000002;ND002;TestMerk
1230000000003;ND003;TestMerk
1230000000004;ND004;TestMerk
1230000000005;ND005;TestMerk
1230000000006, 9789062387410;ND006;TestMerk
1230000000007;ND007;TestMerk
1230000000008;ND008;TestMerk
0071020493219, 0112040014968, 3609740140679, 4716659214199, 4716659214359, 4716659214373, 8862272143272, 9865745929723;90-IGY7002M00-3PA0;Asus
0886227648320, 0886227648351, 0886227648412, 4053162744332, 4716659648352, 4716659648406, 4716659648413, 8862276483206;90IG00W0-BM3G20;Asus
0681495007080;glohdtest;Kobo
5703887123507;nd1235458;Nilfisk
0889894100573;TST1234;Lenovo
0889233045763;tst1111;Lenovo
PARTNERREF001;PARTNERREF001;Acer
32115464163654;9789062387410;AMD

4716659648413;49200;90IG00W0-BM3G20;8;267,23;ASUS
4716659214199;74277;90-IGY7002M01-3PA0-;7;217,56;ASUS
5703887123507;93631;128470701;5;209,16;Nilfisk

5703887123507;nd1235458;Nilfisk;93631;128470701;5;209,16;Nilfisk

awk  '     
BEGIN           {FS = OFS = ";"
                 print "Barcode;Art_ours;Art_Sup;SKU;stock;price;manufacturer"
                }
NR == FNR       {gsub (/ /, "", $1)
                 for (n = split($1, T, ","); n > 0; n--) S[T[n]]=$2
                 next
                }
$1 in S         {$2 = S[$1] OFS $2
                 print
                } 
' file[12]
Barcode;Art_ours;Art_Sup;SKU;stock;price;manufacturer
4716659648413;90IG00W0-BM3G20;49200;90IG00W0-BM3G20;8;267,23;ASUS
4716659214199;90-IGY7002M00-3PA0;74277;90-IGY7002M01-3PA0-;7;217,56;ASUS
5703887123507;nd1235458;93631;128470701;5;209,16;Nilfisk

awk  '                                      
BEGIN           {FS = OFS = ";"                                                   ###### Setting Field seprator and output field seprator as ;
                 print "Barcode;Art_ours;Art_Sup;SKU;stock;price;manufacturer"    ###### print Barcode;Art_ours;Art_Sup;SKU;stock;price;manufacturer in begining of the code execution.
                }
NR == FNR       {gsub (/ /, "", $1)                                               ###### NR==FNR is a condition which willbe TRUE when first file is being read because FNR is a variable which will have the line number same as NR but FNR's value will be reset each time new file is being read and NR's value will be keep increasing till last file completes.
                 for (n = split($1, T, ","); n > 0; n--) S[T[n]]=$2               ###### starting a for loop here, in which an array named T created whose delimiter is ,(comma) only for $1 because split works on method of split(line/field, array_name, delimiter). Now we are taking the count of array T's element into variable n. and for loop will run till n's value is greater than 0. Then we have created array named S whose index is value of array T's value whose index is variable n and assigning array S's value to $2 of file1.
                 next                                                             ###### Now don't do any further action by next keyword and start from condition NR==FNR.
                }
$1 in S         {$2 = S[$1] OFS $2                                                ###### This will be executed while second file file2 is being read, so $1 in S means, any $1's value which is present in array S, if this is TRUE then perform action where make $2(second field's) value to S[$1] OFS $2's value and assign again it to $2 itself.
                 print                                                            ###### Now print the complete line(with new value of $2, which we had formed in previous step.)
                } 
' file[12]                                                                        ###### mentioning Input_files file1 and file2 here.

awk  '
BEGIN           {FS = OFS = ";"                 # set in- and output separator
                 print "Barcode;..."            # print header                
                }
NR == FNR       {gsub (/ /, "", $1)             # remove spaces from first field
                 for (n = split($1, T, ","); n > 0; n--) S[T[n]]=$2
                                                # split SKUs into S array indexed by EANs
                 next                           # skip processing; goto next line
                }
$1 in S         {$2 = S[$1] OFS $2              # if EAN found in S arr: insert SKU into field 2
                 print                          # print modified line
                }
' file[12]