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

FreeBSD Manual Pages

  
 
  

home | help
JOIN(1)			    General Commands Manual		       JOIN(1)

NAME
       join - relational database operator

SYNOPSIS
       join [ options ]	file1 file2

DESCRIPTION
       Join  forms, on the standard output, a join of the two relations	speci-
       fied by the lines of file1 and file2.  If one of	the file names is  the
       standard	input is used.

       File1  and  file2 must be sorted	in increasing ASCII collating sequence
       on the fields on	which they are to be joined,  normally	the  first  in
       each line.

       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.

       Input fields are	normally separated spaces or tabs;  output  fields  by
       space.	In  this  case,	 multiple separators count as one, and leading
       separators are discarded.

       The following options are recognized, with POSIX	syntax.

       -a n   In addition to the normal	output,	produce	a line	for  each  un-
	      pairable line in file n, where n is 1 or 2.

       -v n   Like -a, omitting	output for paired lines.

       -e s   Replace empty output fields by string s.

       -1 m
       -2 m   Join on the mth field of file1 or	file2.

       -jn m  Archaic equivalent for -n	m.

       -ofields
	      Each  output  line  comprises the	designated fields.  The	comma-
	      separated	field designators  are	either	0,  meaning  the  join
	      field, or	have the form n.m, where n is a	file number and	m is a
	      field number.  Archaic usage allows separate arguments for field
	      designators.

       -tc    Use  character  c	as the only separator (tab character) on input
	      and output.  Every appearance of c in a line is significant.

EXAMPLES
       sort /etc/passwd	| join -t: -1 1	-a 1 -e	"" - bdays
	      Add birthdays to the /etc/passwd file, leaving unknown birthdays
	      empty.  The layout of /adm/users is given	in passwd((5));	 bdays
	      contains sorted lines like

       tr : ' '	</etc/passwd | sort -k 3 3 >temp
       join -1 3 -2 3 -o 1.1,2.1 temp temp | awk '$1 < $2'
	      Print all	pairs of users with identical userids.

SOURCE
       /src/cmd/join.c

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

BUGS
       With  default  field separation,	the collating sequence is that of sort
       -b -ky,y; with -t, the sequence is that of sort -tx -ky,y.

       One of the files	must be	randomly accessible.

								       JOIN(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=join&sektion=1&manpath=FreeBSD+Ports+14.3.quarterly>

home | help