3 added 4 characters in body
source | link

join ...

join -1 2 -2 1 FileB FileA

Output

user_a process_1 tel_a addr_a
user_a process_2 tel_a addr_a
user_b process_3 tel_b addr_b

The input files need to be sorted by the key field ... Your example files are already sorted, so there was no need, but otherwise you could incorporate the sort as follows.

join -1 2 -2 1 <(sort -k2 FileB) <(sort FileA)

join ...

join -1 2 -2 1 FileB FileA

Output

user_a process_1 tel_a addr_a
user_a process_2 tel_a addr_a
user_b process_3 tel_b addr_b

The input files need to be sorted by the key field ... Your example files are already sorted, so there was no need, but otherwise you could incorporate the sort as follows.

join -1 2 -2 1 <(sort FileB) <(sort FileA)

join ...

join -1 2 -2 1 FileB FileA

Output

user_a process_1 tel_a addr_a
user_a process_2 tel_a addr_a
user_b process_3 tel_b addr_b

The input files need to be sorted by the key field ... Your example files are already sorted, so there was no need, but otherwise you could incorporate the sort as follows.

join -1 2 -2 1 <(sort -k2 FileB) <(sort FileA)
2 added 88 characters in body
source | link

join  ...

join -1 2 -2 1 FileB FileA

Output

user_a process_1 tel_a addr_a
user_a process_2 tel_a addr_a
user_b process_3 tel_b addr_b

The input files need to be sorted by the key field ... Your example files are already sorted, so there was no need, but otherwise you could incorporate the sort as follows.

join -1 2 -2 1 <(sort FileB) <(sort FileA)

join  

join -1 2 -2 1 FileB FileA

Output

user_a process_1 tel_a addr_a
user_a process_2 tel_a addr_a
user_b process_3 tel_b addr_b

join ...

join -1 2 -2 1 FileB FileA

Output

user_a process_1 tel_a addr_a
user_a process_2 tel_a addr_a
user_b process_3 tel_b addr_b

The input files need to be sorted by the key field ... Your example files are already sorted, so there was no need, but otherwise you could incorporate the sort as follows.

join -1 2 -2 1 <(sort FileB) <(sort FileA)
1
source | link

join

join -1 2 -2 1 FileB FileA

Output

user_a process_1 tel_a addr_a
user_a process_2 tel_a addr_a
user_b process_3 tel_b addr_b