$Field List: Difference between revisions
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<tr><th>olist</th> | <tr><th>olist</th> | ||
<td>The output $list identifier. If the output $list is not empty data is added to the end of the output $list. This is a required argument. </td></tr> | <td>The output $list identifier. If the output $list is not empty, data is added to the end of the output $list. This is a required argument. </td></tr> | ||
<tr><th>fieldname_len</th> | <tr><th>fieldname_len</th> | ||
<td>The length of the output | <td>The length of the output field name in the [[#Output $list format|output $list items]]; it can be any numeric value from 0 to 255. This is an optional argument and defaults to 255. </td></tr> | ||
<tr><th>fieldname</th> | <tr><th>fieldname</th> | ||
<td>The name of the field to be returned. This argument can contain a single specific | <td>The name of the field to be returned. This argument can contain a single specific field name or it can contain a wildcard string that matches a number of fields in the file. This is an optional argument and defaults to asterisk (<tt>*</tt>), which means to return all fields in the record. </td></tr> | ||
<tr><th>options</th> | <tr><th>options</th> | ||
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<table class="syntaxTable"> | <table class="syntaxTable"> | ||
<tr><th><var>TruncLeft</var></th> | <tr><th><var>TruncLeft</var></th> | ||
<td>Truncate | <td>Truncate field names on the left. This is mutually exclusive with the <var>TruncRight</var> and <var>CanTrunc</var> options.</td></tr> | ||
<tr><th><var>TruncRight</var></th> | <tr><th><var>TruncRight</var></th> | ||
<td>Truncate | <td>Truncate field names on the right. This is mutually exclusive with the <var>TruncLeft</var> and <var>CanTrunc</var> options.</td></tr> | ||
<tr><th><var>CanTrunc</var></th> | <tr><th><var>CanTrunc</var></th> | ||
<td>Cancel request on truncated | <td>Cancel request on truncated field name, except when the <var class="term">fieldname_len</var> argument is 0. This is mutually exclusive with the <var>TruncRight</var> and <var>TruncLeft</var> options.</td></tr> | ||
<tr><th><var>TrueLen</var></th> | <tr><th><var>TrueLen</var></th> | ||
<td>Set true | <td>Set true field-name length rather than truncated field name length in the field-name length byte in the output $list. This is mutually exclusive with the <var>TruncLen</var> option.</td></tr> | ||
<tr><th><var>TruncLen</var></th> | <tr><th><var>TruncLen</var></th> | ||
<td>Set truncated | <td>Set truncated field-name length in the field-name length byte in the output $list; this is the default. This is mutually exclusive with the <var>TrueLen</var> option. | ||
</td></tr></table> | </td></tr></table> | ||
</td></tr></table> | </td></tr></table> | ||
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<td>A binary sequence number (same as the $list item number when item added). </td></tr> | <td>A binary sequence number (same as the $list item number when item added). </td></tr> | ||
<tr><th>4-4</th> | <tr><th>4-4</th> | ||
<td>Binary length of | <td>Binary length of field name (true or truncated depending on <var>TrueLen</var>). </td></tr> | ||
<tr><th>5-(5+N-1)</th> | <tr><th>5-(5+N-1)</th> | ||
<td>Blank padded or truncated field name where N is value of argument | <td>Blank padded or truncated field name where N is value of the <var class="term">fieldname_len</var> argument. </td></tr> | ||
<tr><th>5+N-(5+N)</th> | <tr><th>5+N-(5+N)</th> | ||
<td>Binary length of field value. </td></tr> | <td>Binary length of field value. </td></tr> | ||
<tr><th>(5+N+1)-end</th> | <tr><th>(5+N+1)-end</th> | ||
<td>Field value in string format as it would be displayed in a PAI. </td></tr> | <td>Field value in string format as it would be displayed in a <var>PAI</var>. </td></tr> | ||
</table> | </table> | ||
==Usage notes== | ==Usage notes== | ||
<ul> | <ul> | ||
<li>Most | <li>Most field names are typically much shorter than 255 bytes so a large amount of $list space is wasted if the <var class="term">fieldname</var> argument is not specified. | ||
<li>If neither <var>TruncLeft</var> nor <var>TruncRight</var> is specified as an option, a truncated | <li>If neither <var>TruncLeft</var> nor <var>TruncRight</var> is specified as an option, a truncated field name causes request cancellation, except when the <var class="term">fieldname_len</var> argument is 0, in which case <var>TruncLeft</var>, <var>TruncRight</var>, and <var>CanTrunc</var> are meaningless. | ||
<li>Note that you can (bizarrely) specify <var>TrueLen</var> and <var class="term">fieldname_len</var> of 0, which means that while the | <li>Note that you can (bizarrely) specify <var>TrueLen</var> and <var class="term">fieldname_len</var> of 0, which means that while the field name will not be returned, its length will. | ||
<li>The name specified in the <var class="term">fieldname</var> argument can be an explicit name, or it can contain the following wildcard characters: | <li>The name specified in the <var class="term">fieldname</var> argument can be an explicit name, or it can contain the following wildcard characters: | ||
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==Examples== | ==Examples== | ||
The following code fragment retrieves all fields in a record where the | The following code fragment retrieves all fields in a record where the field name begins with the letters "CHILD_" into a $list and sorts the $list by field name. | ||
<p class="code"> | <p class="code">In File INFILE Frn %recno | ||
%rc = $Field_List(%olist, 'CHILD_*', 20) | |||
End For | |||
%slist = $ListSort(%olist, '6,20,A') | |||
</p> | </p> | ||
[[Category:$Functions|$Field_List]] | [[Category:$Functions|$Field_List]] |
Revision as of 16:04, 10 July 2012
Return field values into a $list
Most Sirius $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for $Field_List is the Stringlist AppendFieldValues function.
This function retrieves field values from the current record into a $list. It provides an alternative to PAI INTO.
$Field_List accepts four arguments and returns a number indicating the success of the function.
Syntax
<section begin="syntax" />%rc = $Field_List(olist, [fieldname_len], [fieldname], [options]) <section end="syntax" />
Syntax terms
%rc | A number of items added to olist, or it is or it is one of these (negative) status codes:
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olist | The output $list identifier. If the output $list is not empty, data is added to the end of the output $list. This is a required argument. | ||||||||||
fieldname_len | The length of the output field name in the output $list items; it can be any numeric value from 0 to 255. This is an optional argument and defaults to 255. | ||||||||||
fieldname | The name of the field to be returned. This argument can contain a single specific field name or it can contain a wildcard string that matches a number of fields in the file. This is an optional argument and defaults to asterisk (*), which means to return all fields in the record. | ||||||||||
options | A set of blank-delimited processing options that, starting with Sirius Mods Version 7.1, can be specified in any combination of uppercase and lowercase letters (prior to that, all-uppercase letters are required):
|
Output $list format
Offset | Contents |
---|---|
0-3 | A binary sequence number (same as the $list item number when item added). |
4-4 | Binary length of field name (true or truncated depending on TrueLen). |
5-(5+N-1) | Blank padded or truncated field name where N is value of the fieldname_len argument. |
5+N-(5+N) | Binary length of field value. |
(5+N+1)-end | Field value in string format as it would be displayed in a PAI. |
Usage notes
- Most field names are typically much shorter than 255 bytes so a large amount of $list space is wasted if the fieldname argument is not specified.
- If neither TruncLeft nor TruncRight is specified as an option, a truncated field name causes request cancellation, except when the fieldname_len argument is 0, in which case TruncLeft, TruncRight, and CanTrunc are meaningless.
- Note that you can (bizarrely) specify TrueLen and fieldname_len of 0, which means that while the field name will not be returned, its length will.
- The name specified in the fieldname argument can be an explicit name, or it can contain the following wildcard characters:
* Matches any number of characters including none ? Matches any single character " Indicates that the next character must be treated literally even if it is a wildcard character. For example,
C*D
matches "CUSTID", "COD", or "CLOD"..S??T
matches "SALT", "SLOT", or "SORT"..E"*CONCRETE
matches "E*CONCRETE".
- If a non-wildcard field name is specified for the fieldname argument and the field name does not exist in the file, $Field_List simply returns a 0 without scanning the record. If a wildcard field name is specified for fieldname and the wildcard string does not match any field names in the file, the record is still scanned. Except in the case of a non-wildcard field name that does not exist in the file or a request cancellation because of a truncated field name, or $list or CCATEMP full, the entire record is always scanned.
Examples
The following code fragment retrieves all fields in a record where the field name begins with the letters "CHILD_" into a $list and sorts the $list by field name.
In File INFILE Frn %recno %rc = $Field_List(%olist, 'CHILD_*', 20) End For %slist = $ListSort(%olist, '6,20,A')