join(1) 						      General Commands Manual							   join(1)

NAME

       join - relational database operator

SYNOPSIS

       [options] file1 file2

DESCRIPTION

       forms,  on  the	standard output, a join of the two relations specified by the lines of file1 and file2.  If file1 or file2 is the standard
       input is used.

       file1 and file2 must be sorted in increasing collating sequence (see Environment Variables below) on the fields on which  they  are  to	be
       joined; normally the first in each line.

       The  output contains one line for each pair of lines in file1 and file2 that have identical join fields.  The output line normally consists
       of the common field followed by the rest of the line from file1, then the rest of the line from file2.

       The default input field separators are space, tab, or new-line.	In this case, multiple separators count as one field separator, and  lead-
       ing separators are ignored.  The default output field separator is a space.

       Some of the below options use the argument n.  This argument should be a or a referring to either file1 or file2, respectively.

   Options
       In addition to the normal output,
		   produce a line for each unpairable line in file n, where n is or

       Replace empty output fields by string
		   s.

       Join on field
		   m  of  both	files.	 The argument m must be delimited by space characters.	This option and the following two are provided for
		   backward compatibility.  Use of the and options ( see below ) is recommended for portability.

       Join on field
		   m of file1.

       Join on field
		   m of file2.

       Each output line comprises the fields specified in
		   list, each element of which has the form where n is a file number and m is a field number.  The common  field  is  not  printed
		   unless specifically requested.

       Use character
		   c  as a separator (tab character).  Every appearance of c in a line is significant.	The character c is used as the field sepa-
		   rator for both input and output.

       Instead of the default output,
		   produce a line only for each unpairable line in file_number, where file_number is or

       Join on field
		   f of file 1.  Fields are numbered starting with 1.

       Join on field
		   f of file 2.  Fields are numbered starting with 1.

EXTERNAL INFLUENCES

   Environment Variables
       determines the collating sequence expects from input files.

       determines the alternative blank character as an input field separator, and the interpretation of data within files as single and/or multi-
       byte characters.  also determines whether the separator defined through the option is a single- or multi-byte character.

       If  or  is  not specified in the environment or is set to the empty string, the value of is used as a default for each unspecified or empty
       variable.  If is not specified or is set to the empty string, a default of ``C'' (see lang(5)) is used instead of If any  internationaliza-
       tion variable contains an invalid setting, behaves as if all internationalization variables are set to ``C'' (see environ(5)).

   International Code Set Support
       Single- and multi-byte character code sets are supported with the exception that multi-byte-character file names are not supported.

EXAMPLES

       The following command line joins the password file and the group file, matching on the numeric group ID, and outputting the login name, the
       group name, and the login directory.  It is assumed that the files have been sorted in the collating sequence defined by the or environment
       variable on the group ID fields.

       The  following  command produces an output consisting all possible combinations of lines that have identical first fields in the two sorted
       files sf1 and sf2, with each line consisting of the first and third fields from and the second and fourth fields from

WARNINGS

       With default field separation, the collating sequence is that of with the sequence is that of a plain sort.

       The conventions of and are incongruous.

       Numeric filenames may cause conflict when the option is used immediately before listing filenames.

AUTHOR

       was developed by OSF and HP.

SEE ALSO

       awk(1), comm(1), sort(1), uniq(1).

STANDARDS CONFORMANCE

																	   join(1)