32v 1m join

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JOIN(1) UNIX Programmer's Manual JOIN(1)


NAME

    join - relational database operator

SYNOPSIS

    join [ options ] file1 file2

DESCRIPTION

    _J_o_i_n forms, on the standard output, a join of the two rela-
    tions specified by the lines of _f_i_l_e_1 and _f_i_l_e_2.  If _f_i_l_e_1
    is `-', the standard input is used.
    _F_i_l_e_1 and _f_i_l_e_2 must be sorted in increasing ASCII collating
    sequence on the fields on which they are to be joined, nor-
    mally the first in each line.
    There is one line in the output for each pair of lines in
    _f_i_l_e_1 and _f_i_l_e_2 that have identical join fields.  The output
    line normally consists of the common field, then the rest of
    the line from _f_i_l_e_1, then the rest of the line from _f_i_l_e_2.
    Fields are normally separated by blank, tab or newline.  In
    this case, multiple separators count as one, and leading
    separators are discarded.
    These options are recognized:
    -a_n  In addition to the normal output, produce a line for
         each unpairable line in file _n, where _n is 1 or 2.
    -e _s Replace empty output fields by string _s.
    -j_n _m
         Join on the _mth field of file _n.  If _n is missing, use
         the _mth field in each file.
    -o _l_i_s_t
         Each output line comprises the fields specifed in _l_i_s_t,
         each element of which has the form _n._m, where _n is a
         file number and _m is a field number.
    -t_c  Use character _c as a separator (tab character).  Every
         appearance of _c in a line is significant.

SEE ALSO

    sort(1), comm(1), awk(1)

BUGS

    With default field separation, the collating sequence is
    that of _s_o_r_t -_b; with -t, the sequence is that of a plain
    sort.
    The conventions of _j_o_i_n, _s_o_r_t, _c_o_m_m, _u_n_i_q, _l_o_o_k and _a_w_k(1)
    are wildly incongruous.