60 lines
1.9 KiB
Groff
60 lines
1.9 KiB
Groff
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JOIN(1) Minix Programmer's Manual JOIN(1)
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NAME
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join - relational database operator
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SYNOPSIS
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join [-an] [-e s] [-o list] [-tc] file1 file2
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DESCRIPTION
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Join forms, on the standard output, a join of the two relations specified
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by the lines of file1 and file2. If file1 is `-', the standard input is
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used.
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File1 and file2 must be sorted in increasing ASCII collating sequence on
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the fields on which they are to be joined, normally the first in each
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line.
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There is one line in the output for each pair of lines in file1 and file2
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that have identical join fields. The output line normally consists of
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the common field, then the rest of the line from file1, then the rest of
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the line from file2.
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Fields are normally separated by blank, tab or newline. In this case,
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multiple separators count as one, and leading separators are discarded.
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These options are recognized:
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-an In addition to the normal output, produce a line for each unpairable
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line in file n, where n is 1 or 2.
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-e s Replace empty output fields by string s.
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-o list
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Each output line comprises the fields specified in list, each
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element of which has the form n.m, where n is a file number and m is
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a field number.
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-tc Use character c as a separator (tab character). Every appearance of
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c in a line is significant.
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SEE ALSO
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sort(1), comm(1), awk(1).
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BUGS
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With default field separation, the collating sequence is that of sort -b;
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with -t, the sequence is that of a plain sort.
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The conventions of join, sort, comm, uniq, look and awk(1) are wildly
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incongruous.
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April 29, 1985 1
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