I have two huge input files: file1 contains 3 tabulator separated fields:

field1 - UID

field2 - username

field3 - Real Name

example of file1:

644     u11496   Real name1
640     u1309    Real name2
641     u3007    Real name3
642     u3030    Real name4
643     u3112    Real name5
54      u0365 Real name6
55      u0613 Real name7
56      u1065 Real name8
57      u1550 Real name9

and second file (file2) with many lines each one with 3 tabulator separated fields:

field1 - can be ignored for this case

field2 - group name

field3 - column containing comma-separated UIDs of users

example of file2:

2       group1   14,730,748,733,746,761,757,766,735,760,747,738,752,737,758,755,734,754,764,334,335,336,337,41,338,339,39,340
6       group2        14
15      group3  14,667,683,713,730,707,748,733,746,761,680,694,757,766,717,735,760,747,704,738,752,737,715,688,681,700,692,758,755,714,734

I need to add to each user line in file1, 4th column (tab-separate) with comma-separated group names particular user is member of.

thank you in advance for any hint and ideas.

I have two huge input files:

file1 contains 3 tabulator separated fields:

• field1: UID
• field2: username
• field3: Real Name

Example of file1:

644     u11496   Real name1
640     u1309    Real name2
641     u3007    Real name3
642     u3030    Real name4
643     u3112    Real name5
54      u0365 Real name6
55      u0613 Real name7
56      u1065 Real name8
57      u1550 Real name9

file2 with many lines each one with 3 tabulator separated fields:

• field1: Can be ignored for this case
• field2: Group name
• field3: Column containing comma-separated UIDs of users

Example of file2:

2       group1   14,730,748,733,746,761,757,766,735,760,747,738,752,737,758,755,734,754,764,334,335,336,337,41,338,339,39,340
6       group2        14
15      group3  14,667,683,713,730,707,748,733,746,761,680,694,757,766,717,735,760,747,704,738,752,737,715,688,681,700,692,758,755,714,734

I need to add to each user line in file1, 4th column (tab-separated) with comma-separated group names which a particular user is member of.