<!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>Active Targets (Debugging with GDB)</title> <meta name="description" content="Active Targets (Debugging with GDB)"> <meta name="keywords" content="Active Targets (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="Targets.html#Targets" rel="up" title="Targets"> <link href="Target-Commands.html#Target-Commands" rel="next" title="Target Commands"> <link href="Targets.html#Targets" rel="prev" title="Targets"> <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="Active-Targets"></a> <div class="header"> <p> Next: <a href="Target-Commands.html#Target-Commands" accesskey="n" rel="next">Target Commands</a>, Up: <a href="Targets.html#Targets" accesskey="u" rel="up">Targets</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="Active-Targets-1"></a> <h3 class="section">19.1 Active Targets</h3> <a name="index-stacking-targets"></a> <a name="index-active-targets"></a> <a name="index-multiple-targets"></a> <p>There are multiple classes of targets such as: processes, executable files or recording sessions. Core files belong to the process class, making core file and process mutually exclusive. Otherwise, <small>GDB</small> can work concurrently on multiple active targets, one in each class. This allows you to (for example) start a process and inspect its activity, while still having access to the executable file after the process finishes. Or if you start process recording (see <a href="Reverse-Execution.html#Reverse-Execution">Reverse Execution</a>) and <code>reverse-step</code> there, you are presented a virtual layer of the recording target, while the process target remains stopped at the chronologically last point of the process execution. </p> <p>Use the <code>core-file</code> and <code>exec-file</code> commands to select a new core file or executable target (see <a href="Files.html#Files">Commands to Specify Files</a>). To specify as a target a process that is already running, use the <code>attach</code> command (see <a href="Attach.html#Attach">Debugging an Already-running Process</a>). </p> </body> </html>