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



N\bNA\bAM\bME\bE
    join - relational database operator

S\bSY\bYN\bNO\bOP\bPS\bSI\bIS\bS
    j\bjo\boi\bin\bn [ options ] file1 file2

D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
    _\bJ_\bo_\bi_\bn forms, on the standard output, a join of the two rela-
    tions specified by the lines of _\bf_\bi_\bl_\be_\b1 and _\bf_\bi_\bl_\be_\b2.  If _\bf_\bi_\bl_\be_\b1
    is `-', the standard input is used.

    _\bF_\bi_\bl_\be_\b1 and _\bf_\bi_\bl_\be_\b2 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
    _\bf_\bi_\bl_\be_\b1 and _\bf_\bi_\bl_\be_\b2 that have identical join fields.  The output
    line normally consists of the common field, then the rest of
    the line from _\bf_\bi_\bl_\be_\b1, then the rest of the line from _\bf_\bi_\bl_\be_\b2.

    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:

    -\b-a\ba_\bn  In addition to the normal output, produce a line for
         each unpairable line in file _\bn, where _\bn is 1 or 2.

    -\b-e\be _\bs Replace empty output fields by string _\bs.

    -\b-j\bj_\bn _\bm
         Join on the _\bmth field of file _\bn.  If _\bn is missing, use
         the _\bmth field in each file.

    -\b-o\bo _\bl_\bi_\bs_\bt
         Each output line comprises the fields specified in
         _\bl_\bi_\bs_\bt, each element of which has the form _\bn._\bm, where _\bn
         is a file number and _\bm is a field number.

    -\b-t\bt_\bc  Use character _\bc as a separator (tab character).  Every
         appearance of _\bc in a line is significant.

S\bSE\bEE\bE A\bAL\bLS\bSO\bO
    sort(1), comm(1), awk(1)

B\bBU\bUG\bGS\bS
    With default field separation, the collating sequence is
    that of _\bs_\bo_\br_\bt -_\bb; with -\b-t\bt, the sequence is that of a plain
    sort.





Printed 7/9/88           April 29, 1985                         1






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



    The conventions of _\bj_\bo_\bi_\bn, _\bs_\bo_\br_\bt, _\bc_\bo_\bm_\bm, _\bu_\bn_\bi_\bq, _\bl_\bo_\bo_\bk and _\ba_\bw_\bk(1)
    are wildly incongruous.





















































Printed 7/9/88           April 29, 1985                         2