Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
JOIN(1)			FreeBSD	General	Commands Manual		       JOIN(1)

NAME
     join -- relational	database operator

SYNOPSIS
     join [-a file_number | -v file_number] [-e	string]	[-o list] [-t char]
	  [-1 field] [-2 field]	file1 file2

DESCRIPTION
     The join utility performs an ``equality join'' on the specified files and
     writes the	result to the standard output.	The ``join field'' is the
     field in each file	by which the files are compared.  The first field in
     each line is used by default.  There is one line in the output for	each
     pair of lines in file1 and	file2 which have identical join	fields.	 Each
     output line consists of the join field, the remaining fields from file1
     and then the remaining fields from	file2.

     The default field separators are tab and space characters.	 In this case,
     multiple tabs and spaces count as a single	field separator, and leading
     tabs and spaces are ignored.  The default output field separator is a
     single space character.

     Many of the options use file and field numbers.  Both file	numbers	and
     field numbers are 1 based,	i.e., the first	file on	the command line is
     file number 1 and the first field is field	number 1.  The following
     options are available:

     -a	file_number
	     In	addition to the	default	output,	produce	a line for each
	     unpairable	line in	file file_number.

     -e	string
	     Replace empty output fields with string.

     -o	list
	     The -o option specifies the fields	that will be output from each
	     file for each line	with matching join fields.  Each element of
	     list has either the form file_number.field, where file_number is
	     a file number and field is	a field	number,	or the form `0'
	     (zero), representing the join field.  The elements	of list	must
	     be	either comma (`,') or whitespace separated.  (The latter
	     requires quoting to protect it from the shell, or,	a simpler
	     approach is to use	multiple -o options.)

     -t	char
	     Use character char	as a field delimiter for both input and	out-
	     put.  Every occurrence of char in a line is significant.

     -v	file_number
	     Do	not display the	default	output,	but display a line for each
	     unpairable	line in	file file_number.  The options -v 1 and	-v 2
	     may be specified at the same time.

     -1	field
	     Join on the field'th field	of file1.

     -2	field
	     Join on the field'th field	of file2.

     When the default field delimiter characters are used, the files to	be
     joined should be ordered in the collating sequence	of sort(1), using the
     -b	option,	on the fields on which they are	to be joined, otherwise	join
     may not report all	field matches.	When the field delimiter characters
     are specified by the -t option, the collating sequence should be the same
     as	sort(1)	without	the -b option.

     If	one of the arguments file1 or file2 is `-', the	standard input is
     used.

EXIT STATUS
     The join utility exits 0 on success, and >0 if an error occurs.

COMPATIBILITY
     For compatibility with historic versions of join, the following options
     are available:

     -a	     In	addition to the	default	output,	produce	a line for each
	     unpairable	line in	both file1 and file2.

     -j1 field
	     Join on the field'th field	of file1.

     -j2 field
	     Join on the field'th field	of file2.

     -j	field
	     Join on the field'th field	of both	file1 and file2.

     -o	list ...
	     Historical	implementations	of join	permitted multiple arguments
	     to	the -o option.	These arguments	were of	the form
	     file_number.field_number as described for the current -o option.
	     This has obvious difficulties in the presence of files named 1.2.

     These options are available only so historic shell	scripts	do not require
     modification and should not be used.

SEE ALSO
     awk(1), comm(1), paste(1),	sort(1), uniq(1)

STANDARDS
     The join command conforms to IEEE Std 1003.1-2001 (``POSIX.1'').

FreeBSD	9.3			 July 5, 2004			   FreeBSD 9.3

NAME | SYNOPSIS | DESCRIPTION | EXIT STATUS | COMPATIBILITY | SEE ALSO | STANDARDS

Want to link to this manual page? Use this URL:
<http://www.freebsd.org/cgi/man.cgi?query=join&manpath=FreeBSD+10.0-RELEASE>

home | help