join(1) 							   User Commands							   join(1)

NAME

       join - relational database operator

SYNOPSIS

       join [-a filenumber | -v filenumber] [-1 fieldnumber]
	    [-2 fieldnumber] [-o list] [-e string] [-t char] file1 file2

       join [-a filenumber] [-j fieldnumber] [-j1 fieldnumber]
	    [-j2 fieldnumber] [-o list] [-e string] [-t char] file1 file2

DESCRIPTION

       The join command forms, on the standard output, a join of the two relations specified by the lines of file1 and file2.

       There  is  one  line in the output for each pair of lines in file1 and file2 that have identical join fields. The output line normally con-
       sists of the common field, then the rest of the line from file1, then the rest of the line from file2. This format can be changed by  using
       the  -o	option	(see  below).  The  -a	option	can be used to add unmatched lines to the output. The -v option can be used to output only
       unmatched lines.

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

       If the input files are not in the appropriate collating sequence, the results are unspecified.

OPTIONS

       Some of the options below use the argument filenumber. This argument should be a 1 or a 2 referring to either file1 or file2, respectively.

       -a filenumber	   In  addition to the normal output, produce a line for each unpairable line in file filenumber, where filenumber is 1 or
			   2. If both -a 1 and -a 2 are specified, all unpairable lines will be output.

       -e string	   Replace empty output fields in the list selected by option -o with the string string.

       -j fieldnumber	   Equivalent to -1fieldnumber -2fieldnumber.

       -j1 fieldnumber	   Equivalent to -1fieldnumber.

       -j2 fieldnumber	   Equivalent to -2fieldnumber. Fields are numbered starting with 1.

       -o list		   Each output line includes the fields specified in list. Fields selected by list that do not appear in the input will be
			   treated as empty output fields. (See the -e option.) Each element of which has the either the form filenumber.fieldnum-
			   ber, or 0, which represents the join field. The common field is not printed unless specifically requested.

       -t char		   Use character char as a separator. Every appearance of char in a line is significant. The character char is used as the
			   field  separator  for  both input and output. With this option specified, the collating term should be the same as sort
			   without the -b option.

       -v filenumber	   Instead of the default output, produce a line only for each unpairable line in filenumber, where filenumber is 1 or	2.
			   If both -v 1 and -v 2 are specified, all unpairable lines will be output.

       -1 fieldnumber	   Join on the fieldnumberth field of file 1. Fields are decimal integers starting with 1.

       -2fieldnumber	   Join on the fieldnumberth field of file 2. Fields are decimal integers starting with 1.

OPERANDS

       The following operands are supported:

       file1

       file2	 A path name of a file to be joined. If either of the file1 or file2 operands is -, the standard input is used in its place.

       file1  and  file2 must be sorted in increasing collating sequence as determined by LC_COLLATE on the fields on which they are to be joined,
       normally the first in each line (see sort(1)).

USAGE

       See largefile(5) for the description of the behavior of join when encountering files greater than or equal to 2 Gbyte (2^31 bytes).

EXAMPLES

       Example 1 Joining the password file and group file

       The following command line will join 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 ASCII collating sequence on the group ID fields.

	 example% join -j1 4-j2 3 -o 1.1 2.1 1.6 -t:/etc/passwd /etc/group

       Example 2 Using the -o option

       The -o 0 field essentially selects the union of the join fields. For example, given file phone:

	 !Name		 Phone Number
	 Don		 +1 123-456-7890
	 Hal		 +1 234-567-8901
	 Yasushi	 +2 345-678-9012

       and file fax:

	 !Name		 Fax Number

	 Don		 +1 123-456-7899

	 Keith		 +1 456-789-0122

	 Yasushi	 +2 345-678-9011

       where the large expanses of white space are meant to each represent a single tab character), the command:

	 example% join -t"tab" -a 1 -a 2 -e '(unknown)' -o 0,1.2,2.2 phone fax

       would produce

	 !Name		 Phone Number		Fax Number
	 Don		 +1 123-456-7890	 +1 123-456-7899
	 Hal		 +1 234-567-8901	 (unknown
	 Keith		 (unknown)		 +1 456-789-012
	 Yasushi	 +2 345-678-9012	 +2 345-678-9011

ENVIRONMENT VARIABLES

       See  environ(5)	for descriptions of the following environment variables that affect the execution of join: LANG, LC_ALL, LC_CTYPE, LC_MES-
       SAGES, LC_COLLATE, and NLSPATH.

EXIT STATUS

       The following exit values are returned:

       0      All input files were output successfully.

       >0     An error occurred.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+
       |CSI			     |Enabled			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       awk(1), comm(1), sort(1), uniq(1), attributes(5), environ(5), largefile(5), standards(5)

NOTES

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

       The conventions of the join, sort, comm, uniq, and awk commands are wildly incongruous.

SunOS 5.11							    8 Feb 2000								   join(1)