Re: join man page lacks vital sort reminder

[Jim Meyering]

Dan Jacobson <address@hidden> wrote:
> The vital "FILE1 and FILE2 should be sorted on the join fields" is
> not mentioned on the join man page, only on the Info page.

I guess you're using something older than coreutils-5.2.1.
Here's what I get (as you know, the man page is mechanically
derived from the --help output):

  $ join --help
  Usage: join [OPTION]... FILE1 FILE2
  For each pair of input lines with identical join fields, write a line to
  standard output.  The default join field is the first, delimited
  by whitespace.  When FILE1 or FILE2 (not both) is -, read standard input.

    -a FILENUM        print unpairable lines coming from file FILENUM, where
                        FILENUM is 1 or 2, corresponding to FILE1 or FILE2
    -e EMPTY          replace missing input fields with EMPTY
    -i, --ignore-case ignore differences in case when comparing fields
    -j FIELD          equivalent to `-1 FIELD -2 FIELD'
    -o FORMAT         obey FORMAT while constructing output line
    -t CHAR           use CHAR as input and output field separator
    -v FILENUM        like -a FILENUM, but suppress joined output lines
    -1 FIELD          join on this FIELD of file 1
    -2 FIELD          join on this FIELD of file 2
        --help     display this help and exit
        --version  output version information and exit

  Unless -t CHAR is given, leading blanks separate fields and are ignored,
  else fields are separated by CHAR.  Any FIELD is a field number counted
  from 1.  FORMAT is one or more comma or blank separated specifications,
  each being `FILENUM.FIELD' or `0'.  Default FORMAT outputs the join field,
  the remaining fields from FILE1, the remaining fields from FILE2, all
  separated by CHAR.

  Important: FILE1 and FILE2 must be sorted on the join fields.

  Report bugs to <address@hidden>.