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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"><html><head><!-- Copyright 1997 The Open Group, All Rights Reserved --><title>join</title></head><body bgcolor=white><center><font size=2>The Single UNIX ® Specification, Version 2<br>Copyright © 1997 The Open Group</font></center><hr size=2 noshade><h4><a name = "tag_001_014_1042"> </a>NAME</h4><blockquote>join - relational database operator</blockquote><h4><a name = "tag_001_014_1043"> </a>SYNOPSIS</h4><blockquote><pre><code>join <b>[ </b>-a <i>file_number</i> | -v <i>file_number </i><b>][</b>-e <i>string</i><b>][</b>-o <i>list</i><b>][</b>-t <i>char</i><b>][</b>-1 <i>field</i><b>][</b>-2 <i>field</i><b>]</b><i> file1 file2</i>join <b>[</b>-a <i>file_number</i><b>][</b>-e <i>string</i><b>][</b>-j <i>field</i><b>][</b>-j1 <i>field</i><b>][</b>-j2 <i>field</i><b>][</b>-o <i>list</i>...<b>][</b>-t <i>char</i><b>][</b>-t <i>char</i><b>] </b><i>file1 file2</i></code></pre></blockquote><h4><a name = "tag_001_014_1044"> </a>DESCRIPTION</h4><blockquote>The<i>join</i>utility will perform an equality join on the files<i>file1</i>and<i>file2</i>.The joined files will be written to the standard output.<p>The join field is a field in each file on which the filesare compared.By default,<i>join</i>writes one line in the outputfor each pair of lines in<i>file1</i>and<i>file2</i>that have identical join fields.The output line by default will consist of the join field,then the remaining fields from<i>file1</i>,then the remaining fields from<i>file2</i>.This format can be changed by using the<b>-o</b>option (see below).The<b>-a</b>option can be used to add unmatched lines to the output.The<b>-v</b>option can be used to output only unmatched lines.<p>By default, the files<i>file1</i>and<i>file2</i>should be ordered in the collating sequence of<i><a href="sort.html">sort</a></i><b>-b</b>on the fieldson which they are to be joined,by default the first in each line.All selected output will be written in the same collating sequence.<p>The default input field separators will beblank characters.In this case, multiple separators will count as one field separator, andleading separators will be ignored.The default output field separator will be aspace character.<p>The field separator and collating sequence can be changed by using the<b>-t</b>option (see below).<p>If the input files are not in the appropriate collating sequence,the results are unspecified.</blockquote><h4><a name = "tag_001_014_1045"> </a>OPTIONS</h4><blockquote>The<i>join</i>utility supports the <b>XBD</b> specification, <a href="../xbd/utilconv.html#usg"><b>Utility Syntax Guidelines</b> </a> .The obsolescent version does not follow the utility argumentsyntax guidelines:the<b>-j1</b>and<b>-j2</b>options are multi-character options and the<b>-o</b>option takes multiple arguments.<p>The following options are supported:<dl compact><dt><b>-a </b><i>file_number</i><dd>Produce a line for each unpairable line in file<i>file_number</i>,where<i>file_number</i>is1or2,in addition to the default output.If both<b>-a 1</b>and<b>-a 2</b>are specified, all unpairable lines will be output.<dt><b>-e </b><i>string</i><dd>Replace empty output fields in the list selected by<b>-o</b>with the string<i>string</i>.<dt><b>-j </b><i>field</i><dd>Equivalent to:<b>-1</b><i>field</i><b>-2</b><i>field</i>.<dt><b>-j1 </b><i>field</i><dd>Equivalent to:<b>-1</b><i>field</i>.<dt><b>-j2 </b><i>field</i><dd>Equivalent to:<b>-2</b><i>field</i>.<dt><b>-o </b><i>list</i><dd>Construct the output line to comprise the fields specified in<i>list</i>,each element of whichhas one of the following two forms:<ul><li><i>file_number.field</i>,where<i>file_number</i>is a file number and<i>field</i>is a decimal integer field number<li>0(zero), representing the join field.</ul>The elements of<i>list</i>are either comma- orblank-separated,as specified in Guideline 8 of the <b>XBD</b> specification, <a href="../xbd/utilconv.html#usg"><b>Utility Syntax Guidelines</b> </a> .The fields specified by<i>list</i>will be written for all selected output lines.Fields selected by<i>list</i>that do not appear in theinput will be treated as empty output fields.(See the<b>-e</b>option.)Only specifically requested fields are written.The<i>list</i>must be a single command line argument.However, as an obsolescent feature,the argument<i>list</i>can be multiple arguments on the command line.<dt><b>-t </b><i>char</i><dd>Use character<i>char</i>as a separator, for both input and output.Every appearance of<i>char</i>in a line will be significant.When this option is specified, the collating sequenceshould be the same as<i><a href="sort.html">sort</a></i>without the<b>-b</b>option.<dt><b>-v </b><i>file_number</i><dd>Instead of the default output, produce a line only for eachunpairable line in <i>file_number</i>, where <i>file_number</i> is 1 or 2.If both<b>-v 1</b>and<b>-v 2</b>are specified, all unpairable lines will be output.<dt><b>-1 </b><i>field</i><dd>Join on the<i>field</i>thfield of file 1.Fields are decimal integers starting with 1.<dt><b>-2 </b><i>field</i><dd>Join on the<i>field</i>thfield of file 2.Fields are decimal integers starting with 1.</dl></blockquote><h4><a name = "tag_001_014_1046"> </a>OPERANDS</h4><blockquote>The following operands are supported:<dl compact><dt><i>file1</i><dd><dt><i>file2</i><dd>A pathname of a file to be joined.If either of the<i>file1</i>or<i>file2</i>operands is "-", the standard input is used in its place.</dl></blockquote><h4><a name = "tag_001_014_1047"> </a>STDIN</h4><blockquote>The standard input will be used only if the<i>file1</i>or<i>file2</i>operand is "-".See the INPUT FILES section.</blockquote><h4><a name = "tag_001_014_1048"> </a>INPUT FILES</h4><blockquote>The input files must be text files.</blockquote><h4><a name = "tag_001_014_1049"> </a>ENVIRONMENT VARIABLES</h4><blockquote>The following environment variables affect the execution of<i>join</i>:<dl compact><dt><i>LANG</i><dd>Provide a default value for the internationalisation variablesthat are unset or null.If<i>LANG</i>is unset or null, the corresponding value from theimplementation-dependent default locale will be used.If any of the internationalisation variables contains an invalid setting, theutility will behave as if none of the variables had been defined.<dt><i>LC_ALL</i><dd>If set to a non-empty string value,override the values of all the other internationalisation variables.<dt><i>LC_COLLATE</i><dd>Determine the locale of thecollating sequence<i>join</i>expects to have been used when theinput files were sorted.<dt><i>LC_CTYPE</i><dd>Determine thelocale for the interpretation of sequences of bytes of text data ascharacters (for example, single- as opposed to multi-byte charactersin arguments and input files).<dt><i>LC_MESSAGES</i><dd>Determine the locale that should be used to affectthe format and contents of diagnosticmessages written to standard error.<dt><i>NLSPATH</i><dd>Determine the location of message cataloguesfor the processing of<i>LC_MESSAGES .</i></dl></blockquote><h4><a name = "tag_001_014_1050"> </a>ASYNCHRONOUS EVENTS</h4><blockquote>Default.</blockquote><h4><a name = "tag_001_014_1051"> </a>STDOUT</h4><blockquote>The<i>join</i>utility output will be a concatenation of selected character fields.When the<b>-o</b>option is not specified, the output will be:<p><code><pre><tt>"%s%s%s\n"</tt>, <<i>join field</i>>,<<i>other file1 fields</i>>,<<i>other file2 fields</i>></pre></code><p>If the join field is not the first field ina file, the<<i>other file fields</i>>for that file are:<p><code><pre><<i>fields preceding join field</i>>,<<i>fields following join field</i>></pre></code><p>When the<b>-o</b>option is specified, the output format will be:<p><code><tt>"%s\n"</tt>, <<i>concatenation of fields</i>></code>where the concatenation of fields is described by the<b>-o</b>option, above.<p>For either format,each field (except the last)will be written with its trailing separator character.If the separator is the default(blank characters),a singlespacecharacter will be written after each field (except the last).</blockquote><h4><a name = "tag_001_014_1052"> </a>STDERR</h4><blockquote>Used only for diagnostic messages.</blockquote><h4><a name = "tag_001_014_1053"> </a>OUTPUT FILES</h4><blockquote>None.</blockquote><h4><a name = "tag_001_014_1054"> </a>EXTENDED DESCRIPTION</h4><blockquote>None.</blockquote><h4><a name = "tag_001_014_1055"> </a>EXIT STATUS</h4><blockquote>The following exit values are returned:<dl compact><dt>0<dd>All input files were output successfully.<dt>>0<dd>An error occurred.</dl></blockquote><h4><a name = "tag_001_014_1056"> </a>CONSEQUENCES OF ERRORS</h4><blockquote>Default.</blockquote><h4><a name = "tag_001_014_1057"> </a>APPLICATION USAGE</h4><blockquote>Pathnames consisting of numeric digits or of the form<i>string.string</i>should not be specifieddirectly following the<b>-o</b>list.</blockquote><h4><a name = "tag_001_014_1058"> </a>EXAMPLES</h4><blockquote>The<b>-o 0</b>field essentially selects the union of the join fields.For example, given file<b>phone</b>:<pre><code>!Name Phone NumberDon +1 123-456-7890Hal +1 234-567-8901Yasushi +2 345-678-9012</code></pre>and file<b>fax</b>:<pre><code>!Name Fax NumberDon +1 123-456-7899Keith +1 456-789-0122Yasushi +2 345-678-9011</code></pre>(where the large expanses of white spaceare meant to each represent a singletab character),the command:<pre><code>join -t "<tab>" -a 1 -a 2 -e '(unknown)' -o 0,1.2,2.2 phone fax</code></pre>would produce:<pre><code>!Name Phone Number Fax NumberDon +1 123-456-7890 +1 123-456-7899Hal +1 234-567-8901 (unknown)Keith (unknown) +1 456-789-0122Yasushi +2 345-678-9012 +2 345-678-9011</code></pre></blockquote><h4><a name = "tag_001_014_1059"> </a>FUTURE DIRECTIONS</h4><blockquote>The obsolescent<b>-j</b>options and the multi-argument<b>-o</b>option may be withdrawn in a future issue.</blockquote><h4><a name = "tag_001_014_1060"> </a>SEE ALSO</h4><blockquote><i><a href="awk.html">awk</a></i>,<i><a href="comm.html">comm</a></i>,<i><a href="sort.html">sort</a></i>,<i><a href="uniq.html">uniq</a></i>.</blockquote><hr size=2 noshade><center><font size=2>UNIX ® is a registered Trademark of The Open Group.<br>Copyright © 1997 The Open Group<br> [ <a href="../index.html">Main Index</a> | <a href="../xshix.html">XSH</a> | <a href="../xcuix.html">XCU</a> | <a href="../xbdix.html">XBD</a> | <a href="../cursesix.html">XCURSES</a> | <a href="../xnsix.html">XNS</a> ]</font></center><hr size=2 noshade></body></html>⌨️ 快捷键说明
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