comm(1) 						      General Commands Manual							   comm(1)

NAME

       comm - Compares two sorted files.

SYNOPSIS

       comm [-123] file1 file2

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       command: XCU5.0

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

OPTIONS

       Suppresses  output  of  the  first column (lines in file1 only).  Suppresses output of the second column (lines in file2 only).	Suppresses
       output of the third column (lines common to file1 and file2).

       The command comm -123 produces no output.

OPERANDS

       A pathname of the first file to be compared. If file1 is a hyphen (-), the standard input is used.  A pathname of the  second  file  to	be
       compared. If file2 is a hyphen (-), the standard input is used.

       If both file1 and file2 refer to standard input or to the same FIFO special, block special or character special file, the results are unde-
       fined.

DESCRIPTION

       The comm command reads file1 and file2 and writes three columns to standard output, showing which lines are common to the files	and  which
       are unique to each.

       The  leftmost  column  of  standard output includes lines that are in file1 only.  The middle column includes lines that are in file2 only.
       The rightmost column includes lines that are in both file1 and file2.

       If you specify a hyphen (-) in place of one of the file names, comm reads standard input.

       Generally, file1 and file2 should be sorted according to the collating sequence specified by  the  LC_COLLATE  environment  variable.  (See
       sort(1).)  If the input files are not sorted properly, the output of comm might not be useful.

EXIT STATUS

       Successful completion.  Error occurred.

EXAMPLES

       In the following examples, file1 contains the following sorted list of North American cities:

	      Anaheim Baltimore Boston Chicago Cleveland Dallas Detroit Kansas City Milwaukee Minneapolis New York Oakland Seattle Toronto

	      The second file, file2, contains this sorted list:

	      Atlanta Chicago Cincinnati Houston Los Angeles Montreal New York Philadelphia Pittsburgh San Diego San Francisco St. Louis

	      To display the lines unique to each file and common to the two files, enter: comm file1 file2

	      This command results in the following output: Anaheim	 Atlanta Baltimore Boston	    Chicago	 Cincinnati Cleveland Dal-
	      las Detroit      Houston Kansas City	Los Angeles Milwaukee Minneapolis      Montreal 	  New York Oakland	 Philadel-
	      phia	Pittsburgh	San Diego      San Francisco Seattle	  St. Louis Toronto

	      The  leftmost column contains lines in file1 only, the middle column contains lines in file2 only, and the rightmost column contains
	      lines common to both files.  To display any one or two of the three output columns, include the appropriate flags  to  suppress  the
	      columns you do not want.	For example, the following command displays columns 1 and 2 only: comm -3 file1 file2

	      Anaheim
		     Atlanta Baltimore Boston
		     Cincinnati Cleveland Dallas Detroit
		     Houston Kansas City
		     Los Angeles Milwaukee Minneapolis
		     Montreal Oakland
		     Philadelphia
		     Pittsburgh
		     San Diego
		     San Francisco Seattle
		     St. Louis Toronto

	      The following command displays output from only the second column: comm -13 file1 file2

	      Atlanta Cincinnati Houston Los Angeles Montreal Philadelphia Pittsburgh San Diego San Francisco St. Louis

	      The following command displays output from only the third column: comm -12 file1 file2

	      Chicago New York

SEE ALSO

       Commands:  cmp(1), diff(1), sdiff(1), sort(1), uniq(1)

																	   comm(1)