You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
213 lines
9.8 KiB
HTML
213 lines
9.8 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html>
|
|
<!-- Copyright (C) 1988-2019 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 6.4, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<title>Command Files (Debugging with GDB)</title>
|
|
|
|
<meta name="description" content="Command Files (Debugging with GDB)">
|
|
<meta name="keywords" content="Command Files (Debugging with GDB)">
|
|
<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="Sequences.html#Sequences" rel="up" title="Sequences">
|
|
<link href="Output.html#Output" rel="next" title="Output">
|
|
<link href="Hooks.html#Hooks" rel="prev" title="Hooks">
|
|
<style type="text/css">
|
|
<!--
|
|
a.summary-letter {text-decoration: none}
|
|
blockquote.indentedblock {margin-right: 0em}
|
|
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
|
|
blockquote.smallquotation {font-size: smaller}
|
|
div.display {margin-left: 3.2em}
|
|
div.example {margin-left: 3.2em}
|
|
div.lisp {margin-left: 3.2em}
|
|
div.smalldisplay {margin-left: 3.2em}
|
|
div.smallexample {margin-left: 3.2em}
|
|
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.nolinebreak {white-space: nowrap}
|
|
span.roman {font-family: initial; font-weight: normal}
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
|
ul.no-bullet {list-style: none}
|
|
-->
|
|
</style>
|
|
|
|
|
|
</head>
|
|
|
|
<body lang="en">
|
|
<a name="Command-Files"></a>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Output.html#Output" accesskey="n" rel="next">Output</a>, Previous: <a href="Hooks.html#Hooks" accesskey="p" rel="prev">Hooks</a>, Up: <a href="Sequences.html#Sequences" accesskey="u" rel="up">Sequences</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="Command-Files-1"></a>
|
|
<h4 class="subsection">23.1.3 Command Files</h4>
|
|
|
|
<a name="index-command-files"></a>
|
|
<a name="index-scripting-commands"></a>
|
|
<p>A command file for <small>GDB</small> is a text file made of lines that are
|
|
<small>GDB</small> commands. Comments (lines starting with <kbd>#</kbd>) may
|
|
also be included. An empty line in a command file does nothing; it
|
|
does not mean to repeat the last command, as it would from the
|
|
terminal.
|
|
</p>
|
|
<p>You can request the execution of a command file with the <code>source</code>
|
|
command. Note that the <code>source</code> command is also used to evaluate
|
|
scripts that are not Command Files. The exact behavior can be configured
|
|
using the <code>script-extension</code> setting.
|
|
See <a href="Extending-GDB.html#Extending-GDB">Extending GDB</a>.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dd><a name="index-source"></a>
|
|
<a name="index-execute-commands-from-a-file"></a>
|
|
</dd>
|
|
<dt><code>source [-s] [-v] <var>filename</var></code></dt>
|
|
<dd><p>Execute the command file <var>filename</var>.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>The lines in a command file are generally executed sequentially,
|
|
unless the order of execution is changed by one of the
|
|
<em>flow-control commands</em> described below. The commands are not
|
|
printed as they are executed. An error in any command terminates
|
|
execution of the command file and control is returned to the console.
|
|
</p>
|
|
<p><small>GDB</small> first searches for <var>filename</var> in the current directory.
|
|
If the file is not found there, and <var>filename</var> does not specify a
|
|
directory, then <small>GDB</small> also looks for the file on the source search path
|
|
(specified with the ‘<samp>directory</samp>’ command);
|
|
except that <samp>$cdir</samp> is not searched because the compilation directory
|
|
is not relevant to scripts.
|
|
</p>
|
|
<p>If <code>-s</code> is specified, then <small>GDB</small> searches for <var>filename</var>
|
|
on the search path even if <var>filename</var> specifies a directory.
|
|
The search is done by appending <var>filename</var> to each element of the
|
|
search path. So, for example, if <var>filename</var> is <samp>mylib/myscript</samp>
|
|
and the search path contains <samp>/home/user</samp> then <small>GDB</small> will
|
|
look for the script <samp>/home/user/mylib/myscript</samp>.
|
|
The search is also done if <var>filename</var> is an absolute path.
|
|
For example, if <var>filename</var> is <samp>/tmp/myscript</samp> and
|
|
the search path contains <samp>/home/user</samp> then <small>GDB</small> will
|
|
look for the script <samp>/home/user/tmp/myscript</samp>.
|
|
For DOS-like systems, if <var>filename</var> contains a drive specification,
|
|
it is stripped before concatenation. For example, if <var>filename</var> is
|
|
<samp>d:myscript</samp> and the search path contains <samp>c:/tmp</samp> then <small>GDB</small>
|
|
will look for the script <samp>c:/tmp/myscript</samp>.
|
|
</p>
|
|
<p>If <code>-v</code>, for verbose mode, is given then <small>GDB</small> displays
|
|
each command as it is executed. The option must be given before
|
|
<var>filename</var>, and is interpreted as part of the filename anywhere else.
|
|
</p>
|
|
<p>Commands that would ask for confirmation if used interactively proceed
|
|
without asking when used in a command file. Many <small>GDB</small> commands that
|
|
normally print messages to say what they are doing omit the messages
|
|
when called from command files.
|
|
</p>
|
|
<p><small>GDB</small> also accepts command input from standard input. In this
|
|
mode, normal output goes to standard output and error output goes to
|
|
standard error. Errors in a command file supplied on standard input do
|
|
not terminate execution of the command file—execution continues with
|
|
the next command.
|
|
</p>
|
|
<div class="smallexample">
|
|
<pre class="smallexample">gdb < cmds > log 2>&1
|
|
</pre></div>
|
|
|
|
<p>(The syntax above will vary depending on the shell used.) This example
|
|
will execute commands from the file <samp>cmds</samp>. All output and errors
|
|
would be directed to <samp>log</samp>.
|
|
</p>
|
|
<p>Since commands stored on command files tend to be more general than
|
|
commands typed interactively, they frequently need to deal with
|
|
complicated situations, such as different or unexpected values of
|
|
variables and symbols, changes in how the program being debugged is
|
|
built, etc. <small>GDB</small> provides a set of flow-control commands to
|
|
deal with these complexities. Using these commands, you can write
|
|
complex scripts that loop over data structures, execute commands
|
|
conditionally, etc.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dd><a name="index-if"></a>
|
|
<a name="index-else"></a>
|
|
</dd>
|
|
<dt><code>if</code></dt>
|
|
<dt><code>else</code></dt>
|
|
<dd><p>This command allows to include in your script conditionally executed
|
|
commands. The <code>if</code> command takes a single argument, which is an
|
|
expression to evaluate. It is followed by a series of commands that
|
|
are executed only if the expression is true (its value is nonzero).
|
|
There can then optionally be an <code>else</code> line, followed by a series
|
|
of commands that are only executed if the expression was false. The
|
|
end of the list is marked by a line containing <code>end</code>.
|
|
</p>
|
|
<a name="index-while"></a>
|
|
</dd>
|
|
<dt><code>while</code></dt>
|
|
<dd><p>This command allows to write loops. Its syntax is similar to
|
|
<code>if</code>: the command takes a single argument, which is an expression
|
|
to evaluate, and must be followed by the commands to execute, one per
|
|
line, terminated by an <code>end</code>. These commands are called the
|
|
<em>body</em> of the loop. The commands in the body of <code>while</code> are
|
|
executed repeatedly as long as the expression evaluates to true.
|
|
</p>
|
|
<a name="index-loop_005fbreak"></a>
|
|
</dd>
|
|
<dt><code>loop_break</code></dt>
|
|
<dd><p>This command exits the <code>while</code> loop in whose body it is included.
|
|
Execution of the script continues after that <code>while</code>s <code>end</code>
|
|
line.
|
|
</p>
|
|
<a name="index-loop_005fcontinue"></a>
|
|
</dd>
|
|
<dt><code>loop_continue</code></dt>
|
|
<dd><p>This command skips the execution of the rest of the body of commands
|
|
in the <code>while</code> loop in whose body it is included. Execution
|
|
branches to the beginning of the <code>while</code> loop, where it evaluates
|
|
the controlling expression.
|
|
</p>
|
|
<a name="index-end-_0028if_002felse_002fwhile-commands_0029"></a>
|
|
</dd>
|
|
<dt><code>end</code></dt>
|
|
<dd><p>Terminate the block of commands that are the body of <code>if</code>,
|
|
<code>else</code>, or <code>while</code> flow-control commands.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="Output.html#Output" accesskey="n" rel="next">Output</a>, Previous: <a href="Hooks.html#Hooks" accesskey="p" rel="prev">Hooks</a>, Up: <a href="Sequences.html#Sequences" accesskey="u" rel="up">Sequences</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>
|