1<html lang="en"> 2<head> 3<title>Attach - Debugging with GDB</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="Debugging with GDB"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="up" href="Running.html#Running" title="Running"> 9<link rel="prev" href="Input_002fOutput.html#Input_002fOutput" title="Input/Output"> 10<link rel="next" href="Kill-Process.html#Kill-Process" title="Kill Process"> 11<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 12<!-- 13Copyright (C) 1988-2013 Free Software Foundation, Inc. 14 15Permission is granted to copy, distribute and/or modify this document 16under the terms of the GNU Free Documentation License, Version 1.3 or 17any later version published by the Free Software Foundation; with the 18Invariant Sections being ``Free Software'' and ``Free Software Needs 19Free Documentation'', with the Front-Cover Texts being ``A GNU Manual,'' 20and with the Back-Cover Texts as in (a) below. 21 22(a) The FSF's Back-Cover Text is: ``You are free to copy and modify 23this GNU Manual. 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(<code>info files</code> shows your active 56targets.) The command takes as argument a process ID. The usual way to 57find out the <var>process-id</var> of a Unix process is with the <code>ps</code> utility, 58or with the ‘<samp><span class="samp">jobs -l</span></samp>’ shell command. 59 60 <p><code>attach</code> does not repeat if you press <RET> a second time after 61executing the command. 62</dl> 63 64 <p>To use <code>attach</code>, your program must be running in an environment 65which supports processes; for example, <code>attach</code> does not work for 66programs on bare-board targets that lack an operating system. You must 67also have permission to send the process a signal. 68 69 <p>When you use <code>attach</code>, the debugger finds the program running in 70the process first by looking in the current working directory, then (if 71the program is not found) by using the source file search path 72(see <a href="Source-Path.html#Source-Path">Specifying Source Directories</a>). You can also use 73the <code>file</code> command to load the program. See <a href="Files.html#Files">Commands to Specify Files</a>. 74 75 <p>The first thing <span class="sc">gdb</span> does after arranging to debug the specified 76process is to stop it. You can examine and modify an attached process 77with all the <span class="sc">gdb</span> commands that are ordinarily available when 78you start processes with <code>run</code>. You can insert breakpoints; you 79can step and continue; you can modify storage. If you would rather the 80process continue running, you may use the <code>continue</code> command after 81attaching <span class="sc">gdb</span> to the process. 82 83 84<a name="index-detach-143"></a> 85<dl><dt><code>detach</code><dd>When you have finished debugging the attached process, you can use the 86<code>detach</code> command to release it from <span class="sc">gdb</span> control. Detaching 87the process continues its execution. After the <code>detach</code> command, 88that process and <span class="sc">gdb</span> become completely independent once more, and you 89are ready to <code>attach</code> another process or start one with <code>run</code>. 90<code>detach</code> does not repeat if you press <RET> again after 91executing the command. 92</dl> 93 94 <p>If you exit <span class="sc">gdb</span> while you have an attached process, you detach 95that process. If you use the <code>run</code> command, you kill that process. 96By default, <span class="sc">gdb</span> asks for confirmation if you try to do either of these 97things; you can control whether or not you need to confirm by using the 98<code>set confirm</code> command (see <a href="Messages_002fWarnings.html#Messages_002fWarnings">Optional Warnings and Messages</a>). 99 100 </body></html> 101 102