Linux in a Nutshell, 6th Edition

Name

join

Synopsis

join [options] file1 file2

Join lines of two sorted files by matching on a common field. If either file1 or file2 is -, read from standard input. Often used to merge data stored in text-based file formats such as comma-separated-value formatted spreadsheets.

Options

−1 fieldnum1

The join field in file1 is fieldnum1. Default is the first field.

−2 fieldnum2

The join field in file2 is fieldnum2. Default is the first field.

-a filenum

Print a line for each unpairable line in file filenum, in addition to the normal output.

--check-order, --nocheck-order

Check or do not check that the files are correctly sorted on the join fields.

-e string

Replace missing input fields with string.

-i, --ignore-case

Ignore case differences when comparing fields.

-o fieldlist

Order the output fields according to fieldlist, where each entry in the list is in the form filenum.fieldnum. Entries are separated by commas or blanks.

-t char

Specifies the field-separator character (default is whitespace).

-v filenum

Print only unpairable lines from file filenum.

--help

Print help message and then exit.

--version

Print the version number and then exit.