Combining tab delimited files based on a column value

Suppose I have two tab-delimited files that share a column. Both files have a header line that gives a label to each column. What's an easy way to take the union of the two tables, i.e. take the columns from A and B, but do so according to the value of column K?

for example, table A might be:

employee_id  name
123   john
124   mary

and table B might be:

employee_id  age
124  18
123  22

then the union based on column 1 of table A ("employee_id") should yield the table:

employee_id  name  age
123  john  22
124  mary开发者_开发问答  18

i'd like to do this using Unix utilities, like "cut" etc. how can this be done?

you can use the join utility, but your files need to be sorted first.

join file1 file2

man join for more information

here's a start. I leave you to format the headers as needed

$ awk 'NR>1{a[$1]=a[$1]" "$2}END{for(i in a)print a[i],i}' tableA.txt tableB.txt
 age employee_id
 john 22 123
 mary 18 124

another way

$ join <(sort tableA.txt) <(sort tableB.txt)
123 john 22
124 mary 18
employee_id name age

experiment with the join options when needed (see info page or man page)

Try:

paste file1 file2 > file3