tldr/pages/common/join.md

join

Join lines of two sorted files on a common field. More information: https://www.gnu.org/software/coreutils/manual/html_node/join-invocation.html.

• Join two files on the first (default) field:

join {{path/to/file1}} {{path/to/file2}}

• Join two files using a comma (instead of a space) as the field separator:

join -t {{','}} {{path/to/file1}} {{path/to/file2}}

• Join field3 of file1 with field1 of file2:

join -1 {{3}} -2 {{1}} {{path/to/file1}} {{path/to/file2}}

• Produce a line for each unpairable line for file1:

join -a {{1}} {{path/to/file1}} {{path/to/file2}}

• Join a file from stdin:

cat {{path/to/file1}} | join - {{path/to/file2}}