ug_ch8.htm

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<p>Pages<br>
Sets the number of <b>ida</b>/<b><i>db.*</i></b> virtual memory
database pages.</p>
<p>Max_files<br>
Sets the maximum number of database files that
<b>ida</b>/<b><i>db.*</i></b> can have open at one time. This
number should not be greater than the operating system limit, less
three.</p>
<p>Logging<br>
Toggles the transaction logging option. The screen will indicate
whether transaction logging is on (enabled) or off (disabled).</p>
<p>Chain<br>
Controls the use of the delete chain for storing newly created
records. The display will show whether delete chain usage is on
(enabled) or off (disabled).</p>
<h4>Quit command</h4>
<p><font size="2">Closes any opened database and ends the
<b>ida</b> session. The environment variables DBDPATH and DBFPATH
are restored to their initial values.</font></p>
<h2><a name="Entering" id="Entering"></a>8.3 Entering and Modifying
Records</h2>
<p><font size="2">To edit or modify a database record, you use the
<b>Display/Edit</b> <b>Record</b> submenu. Section 8.3.1 provides
information about the commands on the <b>Display/Edit Record</b>
submenu. Section 8.3.2 gives instructions for editing a data field
and section 8.3.3 provides information about <b>ida</b>'s editing
modes and describes <b>ida</b>'s field editing commands.</font></p>
<h3><a name="AccessingDisplay" id="AccessingDisplay"></a>8.3.1
Accessing the Display/Edit Record Submenu</h3>
<p><font size="2">To access an existing record with the
<b>Display/Edit</b> submenu:</font></p>
<ul>
<li>Open the database you want.</li>
<li>Access the <b>Database Access Commands</b> and <b>Record</b>
submenus.</li>
<li>Select a record from the database. You may use the
<b>Keyscan</b>, <b>Get</b>, or <b>Recscan</b> options to select a
record. The record will be made the <i>current record</i>.</li>
<li>From the <b>Record Manipulation Functions</b> submenu (Figure
8-4), select <b>Modify</b> to display the <b>Display/Edit
Record</b> submenu.</li>
</ul>
<p>When the <b>Display/Edit Record</b> submenu is accessed, the
current record is displayed. Header information identifies the name
of the record, its length in bytes, the total number of data fields
that can be edited, the current page number, and total pages of
data fields for the record.</p>
<p>Following the header is the first page of fields. The name of
the data field appears on the left, its contents appear on the
right. An example display is shown in Figure 8-7 below.</p>
<hr>
<pre>
<font color="#0000FF"><b>Display/Edit Record</b>
Edit Init Next Prev Write Store_key Delete_key Owner Connect X_Exit
Edit record
<br>
RECORD: INFO       SIZE: 220   TOTAL FIELDS: 5            PAGE 1 OF 1
<br>
ID_CODE            &gt;sw001&lt;
INFO_TITLE         &gt;Software Reliability Principles &amp; Practices&lt;
PUBLISHER          &gt;Wiley-Interscience&lt;
PUB_DATE           &gt;1976&lt;
INFO_TYPE          &gt;0&lt;</font><font size="2">
</font>
</pre>
<hr>
<p align="center"><b>Fig. 8-7. An Example Display/Edit Record
Screen</b></p>
<p>To create a new record with the <b>Display/Edit</b> submenu:</p>
<ul>
<li>Open the database you want.</li>
<li>Access the <b>Database Access Commands</b> and <b>Record</b>
submenus.</li>
<li>Select the <b>Enter</b> submenu and select a record type from
the list.</li>
<li>The <b>Display/Edit</b> submenu will show the record
information (as in Figure 8-7) with empty field contents.</li>
</ul>
<p>A field can be edited if it is not the sub-field of a
<b>struct</b>. Select the <b>Edit</b> submenu command to change
individual field contents.</p>
<h3><a name="UsingDisplay" id="UsingDisplay"></a>8.3.2 Using the
Display/Edit Record Submenu Commands</h3>
<p><font size="2">Figure 8-8 shows the <b>Display/Edit Record</b>
submenu commands.</font></p>
<hr>
<pre>
<b><font color="#0000FF">Display/Edit Record</font>
Edit Init Next Prev Write Store_key Delete_key Owner Connect X_exit</b>
</pre>
<hr>
<p align="center"><font size="2"><b>Fig. 8-8. The Display/Edit
Record Submenu</b></font></p>
<p>The first line is the menu title, and the second line lists the
menu commands. This section describes each of these commands.</p>
<h4>Edit command</h4>
<p><font size="2">Selecting this command invokes field-level
editing of the displayed record. The field edit commands are listed
in Table 8-2. The first field is highlighted and displayed in the
data field edit area. Field editing is initially entered in Command
mode. For information about <b>ida</b> editing modes, see section
8.3.4.</font></p>
<h4>Init command</h4>
<p><font size="2">Use this command to initialize a new record.
Selecting this command clears the displayed record and enters field
editing (see section 8.3.4) in Insert mode.</font></p>
<h4>Next command</h4>
<p><font size="2">If the displayed record type consists of more
data fields than can be shown on one screen, this command can be
used to display the next page of fields. Note that when entering
data, each page of data fields must be entered before the record is
stored. Use the <b>Next</b> command to access each page.</font></p>
<h4>Prev command</h4>
<p><font size="2">Selecting this command displays the previous page
of data fields. Each page of data fields must be entered before the
record is stored.</font></p>
<h4>Write command</h4>
<p><font size="2">Selecting this command writes the entered or
modified record to the database. If the automatic set connection
feature is enabled, then the record will also be connected to each
set of which it is a member and for which a current owner has
previously been set.</font></p>
<h4>Store_key command</h4>
<p><font size="2">This command is used to store optional keys in
the key file. A selection list of optional keys will be displayed.
Select the one to be stored for the current record.</font></p>
<h4>Delete_key command</h4>
<p><font size="2">This command is used to delete optional keys from
the key file. A selection list of optional keys will be displayed.
Select the one to be deleted from the current record.</font></p>
<h4>Owner command</h4>
<p><font size="2">This command is used to assign, from the current
record, the current owner of the selected set. It is provided here
to facilitate data entry. Note that all sets are listed, but not
all sets will allow the current record to be the owner
record.</font></p>
<h4>Connect command</h4>
<p><font size="2">Selecting this command connects the current
record to the set selected from the displayed list of sets. It is
provided here to facilitate data entry. Note that all sets are
listed, but not all sets will allow the current record to be a
member record. To succeed, the current record must be of the
correct type, must not already be connected to the set, and a
current owner for the set instance must already be
established.</font></p>
<h3><a name="DataField" id="DataField"></a>8.3.3 Editing a Data
Field</h3>
<p><font size="2">In the <b>Display/Edit Record</b> submenu,
selecting the <b>Edit</b> or the <b>Init</b> command allows you to
edit a record one data field at a time. <b>ida</b> editing
incorporates many of the VI editor commands (see Table
8-2).</font></p>
<p>All editing is performed in the editing field. Just above the
editing field, the name of the field being edited is displayed. If
this field already contains data, the data will be displayed in the
editing field. Arrows on either end of the editing field point
inward if all the data in the field fits on the screen, or outward
in the direction where more data can be found. The entire contents
of the field are accessed by horizontally scrolling or
repositioning through the field, using cursor-positioning field
edit commands.</p>
<p>You can move to different data fields by using the up and down
arrow keys, or by pressing &lt;Enter&gt; or &lt;Tab&gt; to move to
the next field. Pressing &lt;Enter&gt; or &lt;Tab&gt; on the last
field, or pressing &lt;Esc&gt; at any point, will return you to the
<b>Display/Edit Record</b> submenu.</p>
<p>The format of the displayed data is similar to the format that
would be used if the data were statically initialized in a C
variable declaration. Each item of an arrayed (non- string) data
field is separated by commas and specified in its natural sequence.
Structure fields must be enclosed by braces ({ }). Character
strings do not need to be delimited by quotation marks except when
included as part of a <b>struct</b> field. Sub-fields of
<b>struct</b> fields cannot be edited independently and, in fact,
they are displayed only in the <b>struct</b> field. All C escape
codes (for example, <b>\n, \f, \r, \ddd</b>) can be entered into
character fields.</p>
<p>One-dimensional character arrays are always treated as strings,
terminated by a null byte (<b>\</b>0). Multi-dimensional character
arrays will display the entire length of the field.</p>
<p>Fields of type <b>DB_ADDR</b> are displayed and entered as <b>[f
:r]</b>, where <b><i>f</i></b> is the file number and
<b><i>r</i></b> is the record number. As an example,
<b>[3:11717]</b> is the database address of the record located at
slot number 11717 in file number 3.</p>
<p>Repeating data items in arrayed data fields are indicated with a
<b>d*</b> prefix where <b>d</b> is the decimal number of
repetitions and "<b>*</b>" indicates a repeating field.</p>
<p>The following table lists some examples of the above
requirements.</p>
<p align="center"><b>Table 8-1. Example Data Field Contents</b></p>
<table border="0" cellpadding="7" cellspacing="0" width="542">
<tr>
<td valign="top" width="28%">
<p><b><font size="2"><font face="Default">Field
Spec</font></font></b></p>
</td>
<td valign="top" width="72%">
<p><b><font size="2"><font face=
"Default">Display</font></font></b></p>
</td>
</tr>
<tr>
<td valign="top" width="28%">
<p><font face="Courier" size="1">char str[255];</font></p>
</td>
<td valign="top" width="72%">
<p><font face="Courier" size="1">This needs to be scrolled to see
th&gt;</font></p>
</td>
</tr>
<tr>
<td valign="top" width="28%">
<p><font face="Courier" size="1">int array[10];</font></p>
</td>
<td valign="top" width="72%">
<p><font face="Courier" size=
"1">&gt;12,15,312,74,5,5*0&lt;</font></p>
</td>
</tr>
<tr>
<td valign="top" width="28%">
<p><font face="Courier" size="1">struct {</font></p>
</td>
<td valign="top" width="72%">
<p><font face="Courier" size=
"1">&gt;{"Joelle",6},{"Rebecca",4},{"Scott",2},{"K&amp;
&gt;</font></p>
</td>
</tr>
<tr>
<td valign="top" width="28%">
<p><font face="Courier" size="1">char name[15];<br>
int age;<br>
} children[7];</font></p>
</td>
<td valign="top" width="72%">&nbsp;</td>
</tr>
<tr>
<td valign="top" width="28%">
<p><font face="Courier" size="1">DB_ADDR tree[2];</font></p>
</td>
<td valign="top" width="72%">
<p><font face="Courier" size=
"1">&gt;[2:1377],[2:1381]&lt;</font></p>
</td>
</tr>
<tr>
<td valign="top" width="28%">
<p><font face="Courier" size="1">char lines[10][10]</font></p>
</td>
<td valign="top" width="72%">
<p><font face="Courier" size="1">&gt;line 1\n\0\0\0line
2\n\0\0\0line3\n\&gt;</font></p>
</td>
</tr>
</table>
<h3><a name="EditCommands" id="EditCommands"></a>8.3.4 Using Edit
Modes and Field Edit Commands</h3>
<p><font size="2">The current editing mode is shown in the upper
right corner of the screen. There are three modes:</font></p>
<div style="margin-left: 4em">
<p>Command mode indicates that the field edit commands are enabled.
Table 8-2 lists the edit commands available in Command mode.</p>
<p>Insert mode is initiated by the <b>i</b>, <b>a</b>, and <b>A</b>
commands, allowing data to be inserted into the field. Pressing
&lt;Esc&gt; returns to Command mode.</p>
<p>Replace mode (<b>R</b> command) allows a type-over capability,
where characters under the cursor are replaced by those typed at
the keyboard. Pressing &lt;Esc&gt; returns to Command mode.</p>
</div>
<p align="center"><b>Table 8-2. ida Field Edit Commands and
Descriptions</b></p>
<p align="center">&nbsp;</p>
<center>
<table border="1" cellpadding="7" cellspacing="1" width="537">
<tbody>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">Command</font></b></p>
</td>
<td valign="top" width="79%">
<p><b><font size="2">Description</font></b></p>
</td>
</tr>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">i</font></b></p>
</td>
<td valign="top" width="79%">
<p><font size="2">Insert characters before the cursor.</font></p>
</td>
</tr>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">a</font></b></p>
</td>
<td valign="top" width="79%">
<p><font size="2">Append characters after the cursor.</font></p>
</td>
</tr>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">A</font></b></p>
</td>
<td valign="top" width="79%">
<p><font size="2">Append characters to the end of the
field.</font></p>
</td>
</tr>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">r</font></b></p>
</td>
<td valign="top" width="79%">
<p><font size="2">Replace one character.</font></p>
</td>
</tr>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">R</font></b></p>
</td>
<td valign="top" width="79%">
<p><font size="2">Replace (types over) existing
characters.</font></p>
</td>
</tr>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">h</font></b></p>
</td>
<td valign="top" width="79%">
<p><font size="2">Move the cursor one character to the
left.</font></p>
</td>
</tr>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">l</font></b></p>
</td>
<td valign="top" width="79%">
<p><font size="2">Move the cursor one character to the
right.</font></p>
</td>
</tr>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">w</font></b></p>
</td>
<td valign="top" width="79%">
<p><font size="2">Move the cursor forward one "small" word,
delimited by anything other than letters, digits, or
underscores.</font></p>
</td>
</tr>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">W</font></b></p>
</td>
<td valign="top" width="79%">
<p><font size="2">Move cursor forward one "big" word, delimited by
spaces.</font></p>
</td>
</tr>
<tr>
<td valign="top" width="21%">
<p><b><font size="2">b</font></b></p>