mingw/info/gdb/Data.html

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  12 Node:<a name="Data">Data</a>,
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  18
  19 <h2 class="chapter">Examining Data</h2>
  20
  21    <p>The usual way to examine data in your program is with the <code>print</code>
  22 command (abbreviated <code>p</code>), or its synonym <code>inspect</code>.  It
  23 evaluates and prints the value of an expression of the language your
  24 program is written in (see <a href="Languages.html#Languages">Using GDB with Different Languages</a>).
  25
  26      <dl>
  27 <dt><code>print </code><var>expr</var><code></code>
  28      <dd><dt><code>print /</code><var>f</var><code> </code><var>expr</var><code></code>
  29      <dd><var>expr</var> is an expression (in the source language).  By default the
  30 value of <var>expr</var> is printed in a format appropriate to its data type;
  31 you can choose a different format by specifying <code>/</code><var>f</var><code></code>, where
  32 <var>f</var> is a letter specifying the format; see <a href="Output-Formats.html#Output%20Formats">Output formats</a>.
  33
  34      <br><dt><code>print</code>
  35      <dd><dt><code>print /</code><var>f</var><code></code>
  36      <dd>If you omit <var>expr</var>, GDB displays the last value again (from the
  37 <dfn>value history</dfn>; see <a href="Value-History.html#Value%20History">Value history</a>).  This allows you to
  38 conveniently inspect the same value in an alternative format.
  39 </dl>
  40
  41    <p>A more low-level way of examining data is with the <code>x</code> command.
  42 It examines data in memory at a specified address and prints it in a
  43 specified format.  See <a href="Memory.html#Memory">Examining memory</a>.
  44
  45    <p>If you are interested in information about types, or about how the
  46 fields of a struct or a class are declared, use the <code>ptype </code><var>exp</var><code></code>
  47 command rather than <code>print</code>.  See <a href="Symbols.html#Symbols">Examining the Symbol Table</a>.
  48
  49 <ul class="menu">
  50 <li><a accesskey="1" href="Expressions.html#Expressions">Expressions</a>:                  Expressions
  51 <li><a accesskey="2" href="Variables.html#Variables">Variables</a>:                    Program variables
  52 <li><a accesskey="3" href="Arrays.html#Arrays">Arrays</a>:                       Artificial arrays
  53 <li><a accesskey="4" href="Output-Formats.html#Output%20Formats">Output Formats</a>:               Output formats
  54 <li><a accesskey="5" href="Memory.html#Memory">Memory</a>:                       Examining memory
  55 <li><a accesskey="6" href="Auto-Display.html#Auto%20Display">Auto Display</a>:                 Automatic display
  56 <li><a accesskey="7" href="Print-Settings.html#Print%20Settings">Print Settings</a>:               Print settings
  57 <li><a accesskey="8" href="Value-History.html#Value%20History">Value History</a>:                Value history
  58 <li><a accesskey="9" href="Convenience-Vars.html#Convenience%20Vars">Convenience Vars</a>:             Convenience variables
  59 <li><a href="Registers.html#Registers">Registers</a>:                    Registers
  60 <li><a href="Floating-Point-Hardware.html#Floating%20Point%20Hardware">Floating Point Hardware</a>:      Floating point hardware
  61 <li><a href="Memory-Region-Attributes.html#Memory%20Region%20Attributes">Memory Region Attributes</a>:     Memory region attributes
  62 </ul>
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