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diff --git a/share/doc/gdb/Output-Formats.html b/share/doc/gdb/Output-Formats.html new file mode 100644 index 0000000..7da299d --- /dev/null +++ b/share/doc/gdb/Output-Formats.html @@ -0,0 +1,204 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 Free Software Foundation, Inc. + +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 or +any later version published by the Free Software Foundation; with the +Invariant Sections being "Free Software" and "Free Software Needs +Free Documentation", with the Front-Cover Texts being "A GNU Manual," +and with the Back-Cover Texts as in (a) below. + +(a) The FSF's Back-Cover Text is: "You are free to copy and modify +this GNU Manual. Buying copies from GNU Press supports the FSF in +developing GNU and promoting software freedom." --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Debugging with GDB: Output Formats</title> + +<meta name="description" content="Debugging with GDB: Output Formats"> +<meta name="keywords" content="Debugging with GDB: Output Formats"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="makeinfo"> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<link href="index.html#Top" rel="start" title="Top"> +<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Data.html#Data" rel="up" title="Data"> +<link href="Memory.html#Memory" rel="next" title="Memory"> +<link href="Arrays.html#Arrays" rel="previous" title="Arrays"> +<style type="text/css"> +<!-- +a.summary-letter {text-decoration: none} +blockquote.smallquotation {font-size: smaller} +div.display {margin-left: 3.2em} +div.example {margin-left: 3.2em} +div.indentedblock {margin-left: 3.2em} +div.lisp {margin-left: 3.2em} +div.smalldisplay {margin-left: 3.2em} +div.smallexample {margin-left: 3.2em} +div.smallindentedblock {margin-left: 3.2em; font-size: smaller} +div.smalllisp {margin-left: 3.2em} +kbd {font-style:oblique} +pre.display {font-family: inherit} +pre.format {font-family: inherit} +pre.menu-comment {font-family: serif} +pre.menu-preformatted {font-family: serif} +pre.smalldisplay {font-family: inherit; font-size: smaller} +pre.smallexample {font-size: smaller} +pre.smallformat {font-family: inherit; font-size: smaller} +pre.smalllisp {font-size: smaller} +span.nocodebreak {white-space:nowrap} +span.nolinebreak {white-space:nowrap} +span.roman {font-family:serif; font-weight:normal} +span.sansserif {font-family:sans-serif; font-weight:normal} +ul.no-bullet {list-style: none} +--> +</style> + + +</head> + +<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="Output-Formats"></a> +<div class="header"> +<p> +Next: <a href="Memory.html#Memory" accesskey="n" rel="next">Memory</a>, Previous: <a href="Arrays.html#Arrays" accesskey="p" rel="previous">Arrays</a>, Up: <a href="Data.html#Data" accesskey="u" rel="up">Data</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Output-Formats-1"></a> +<h3 class="section">10.5 Output Formats</h3> + +<a name="index-formatted-output"></a> +<a name="index-output-formats"></a> +<p>By default, <small>GDB</small> prints a value according to its data type. Sometimes +this is not what you want. For example, you might want to print a number +in hex, or a pointer in decimal. Or you might want to view data in memory +at a certain address as a character string or as an instruction. To do +these things, specify an <em>output format</em> when you print a value. +</p> +<p>The simplest use of output formats is to say how to print a value +already computed. This is done by starting the arguments of the +<code>print</code> command with a slash and a format letter. The format +letters supported are: +</p> +<dl compact="compact"> +<dt><code>x</code></dt> +<dd><p>Print the binary representation of the value in hexadecimal. +</p> +</dd> +<dt><code>d</code></dt> +<dd><p>Print the binary representation of the value in decimal. +</p> +</dd> +<dt><code>u</code></dt> +<dd><p>Print the binary representation of the value as an decimal, as if it +were unsigned. +</p> +</dd> +<dt><code>o</code></dt> +<dd><p>Print the binary representation of the value in octal. +</p> +</dd> +<dt><code>t</code></dt> +<dd><p>Print the binary representation of the value in binary. The letter +‘<samp>t</samp>’ stands for “two”. <a name="DOCF11" href="#FOOT11"><sup>11</sup></a> +</p> +</dd> +<dt><code>a</code></dt> +<dd><a name="index-unknown-address_002c-locating"></a> +<a name="index-locate-address"></a> +<p>Print as an address, both absolute in hexadecimal and as an offset from +the nearest preceding symbol. You can use this format used to discover +where (in what function) an unknown address is located: +</p> +<div class="smallexample"> +<pre class="smallexample">(gdb) p/a 0x54320 +$3 = 0x54320 <_initialize_vx+396> +</pre></div> + +<p>The command <code>info symbol 0x54320</code> yields similar results. +See <a href="Symbols.html#Symbols">info symbol</a>. +</p> +</dd> +<dt><code>c</code></dt> +<dd><p>Cast the value to an integer (unlike other formats, this does not just +reinterpret the underlying bits) and print it as a character constant. +This prints both the numerical value and its character representation. +The character representation is replaced with the octal escape +‘<samp>\nnn</samp>’ for characters outside the 7-bit <small>ASCII</small> range. +</p> +<p>Without this format, <small>GDB</small> displays <code>char</code>, +<code>unsigned char</code><!-- /@w -->, and <code>signed char</code><!-- /@w --> data as character +constants. Single-byte members of vectors are displayed as integer +data. +</p> +</dd> +<dt><code>f</code></dt> +<dd><p>Regard the bits of the value as a floating point number and print +using typical floating point syntax. +</p> +</dd> +<dt><code>s</code></dt> +<dd><a name="index-printing-strings"></a> +<a name="index-printing-byte-arrays"></a> +<p>Regard as a string, if possible. With this format, pointers to single-byte +data are displayed as null-terminated strings and arrays of single-byte data +are displayed as fixed-length strings. Other values are displayed in their +natural types. +</p> +<p>Without this format, <small>GDB</small> displays pointers to and arrays of +<code>char</code>, <code>unsigned char</code><!-- /@w -->, and <code>signed char</code><!-- /@w --> as +strings. Single-byte members of a vector are displayed as an integer +array. +</p> +</dd> +<dt><code>z</code></dt> +<dd><p>Like ‘<samp>x</samp>’ formatting, the value is treated as an integer and +printed as hexadecimal, but leading zeros are printed to pad the value +to the size of the integer type. +</p> +</dd> +<dt><code>r</code></dt> +<dd><a name="index-raw-printing"></a> +<p>Print using the ‘<samp>raw</samp>’ formatting. By default, <small>GDB</small> will +use a Python-based pretty-printer, if one is available (see <a href="Pretty-Printing.html#Pretty-Printing">Pretty Printing</a>). This typically results in a higher-level display of the +value’s contents. The ‘<samp>r</samp>’ format bypasses any Python +pretty-printer which might exist. +</p></dd> +</dl> + +<p>For example, to print the program counter in hex (see <a href="Registers.html#Registers">Registers</a>), type +</p> +<div class="smallexample"> +<pre class="smallexample">p/x $pc +</pre></div> + +<p>Note that no space is required before the slash; this is because command +names in <small>GDB</small> cannot contain a slash. +</p> +<p>To reprint the last value in the value history with a different format, +you can use the <code>print</code> command with just a format and no +expression. For example, ‘<samp>p/x</samp>’ reprints the last value in hex. +</p> +<div class="footnote"> +<hr> +<h4 class="footnotes-heading">Footnotes</h4> + +<h3><a name="FOOT11" href="#DOCF11">(11)</a></h3> +<p>‘<samp>b</samp>’ cannot be used +because these format letters are also used with the <code>x</code> command, +where ‘<samp>b</samp>’ stands for “byte”; see <a href="Memory.html#Memory">Examining +Memory</a>.</p> +</div> +<hr> +<div class="header"> +<p> +Next: <a href="Memory.html#Memory" accesskey="n" rel="next">Memory</a>, Previous: <a href="Arrays.html#Arrays" accesskey="p" rel="previous">Arrays</a>, Up: <a href="Data.html#Data" accesskey="u" rel="up">Data</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |