Section (1) join


Linux manual pages Section 1  

Name

join — join lines of two files on a common field

Synopsis

join [OPTION...] FILE1 FILE2

DESCRIPTION

For each pair of input lines with identical join fields, write a line to standard output. The default join field is the first, delimited by blanks.

When FILE1 or FILE2 (not both) is −, read standard input.

−a FILENUM

also print unpairable lines from file FILENUM, where FILENUM is 1 or 2, corresponding to FILE1 or FILE2

−e EMPTY

replace missing input fields with EMPTY

−i, −−ignore−case

ignore differences in case when comparing fields

−j FIELD

equivalent to _zsingle_quotesz_−1 FIELD −2 FIELD_zsingle_quotesz_

−o FORMAT

obey FORMAT while constructing output line

−t CHAR

use CHAR as input and output field separator

−v FILENUM

like −a FILENUM, but suppress joined output lines

−1 FIELD

join on this FIELD of file 1

−2 FIELD

join on this FIELD of file 2

−−check−order

check that the input is correctly sorted, even if all input lines are pairable

−−nocheck−order

do not check that the input is correctly sorted

−−header

treat the first line in each file as field headers, print them without trying to pair them

−z, −−zero−terminated

line delimiter is NUL, not newline

−−help

display this help and exit

−−version

output version information and exit

Unless −t CHAR is given, leading blanks separate fields and are ignored, else fields are separated by CHAR. Any FIELD is a field number counted from 1. FORMAT is one or more comma or blank separated specifications, each being _zsingle_quotesz_FILENUM.FIELD_zsingle_quotesz_ or _zsingle_quotesz_0_zsingle_quotesz_. Default FORMAT outputs the join field, the remaining fields from FILE1, the remaining fields from FILE2, all separated by CHAR. If FORMAT is the keyword _zsingle_quotesz_auto_zsingle_quotesz_, then the first line of each file determines the number of fields output for each line.

Important: FILE1 and FILE2 must be sorted on the join fields. E.g., use sort −k 1b,1 if _zsingle_quotesz_join_zsingle_quotesz_ has no options, or use join −t _zsingle_quotesz__zsingle_quotesz_ if _zsingle_quotesz_sort_zsingle_quotesz_ has no options. Note, comparisons honor the rules specified by _zsingle_quotesz_LC_COLLATE_zsingle_quotesz_. If the input is not sorted and some lines cannot be joined, a warning message will be given.

AUTHOR

Written by Mike Haertel.

REPORTING BUGS

GNU coreutils online help: <https://www.gnu.org/software/coreutils/>

Report any translation bugs to <https://translationproject.org/team/>

SEE ALSO

comm(1), uniq(1)

Full documentation <https://www.gnu.org/software/coreutils/join>

or available locally via: info _zsingle_quotesz_(coreutils) join invocation_zsingle_quotesz_

COPYRIGHT

Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.

This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.