<html lang="en">
<head>
<title>strip - GNU Binary Utilities</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="GNU Binary Utilities">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="prev" href="strings.html#strings" title="strings">
<link rel="next" href="c_002b_002bfilt.html#c_002b_002bfilt" title="c++filt">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
Copyright (C) 1991-2019 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 no Invariant Sections, with no Front-Cover Texts, and with no
Back-Cover Texts.  A copy of the license is included in the
section entitled ``GNU Free Documentation License''.

-->
<meta http-equiv="Content-Style-Type" content="text/css">
<style type="text/css"><!--
  pre.display { font-family:inherit }
  pre.format  { font-family:inherit }
  pre.smalldisplay { font-family:inherit; font-size:smaller }
  pre.smallformat  { font-family:inherit; font-size:smaller }
  pre.smallexample { font-size:smaller }
  pre.smalllisp    { font-size:smaller }
  span.sc    { font-variant:small-caps }
  span.roman { font-family:serif; font-weight:normal; } 
  span.sansserif { font-family:sans-serif; font-weight:normal; } 
--></style>
</head>
<body>
<div class="node">
<a name="strip"></a>
<p>
Next:&nbsp;<a rel="next" accesskey="n" href="c_002b_002bfilt.html#c_002b_002bfilt">c++filt</a>,
Previous:&nbsp;<a rel="previous" accesskey="p" href="strings.html#strings">strings</a>,
Up:&nbsp;<a rel="up" accesskey="u" href="index.html#Top">Top</a>
<hr>
</div>

<h2 class="chapter">8 strip</h2>

<p><a name="index-strip-133"></a><a name="index-removing-symbols-134"></a><a name="index-discarding-symbols-135"></a><a name="index-symbols_002c-discarding-136"></a>
<!-- man title strip discard symbols and other data from object files -->

<pre class="smallexample">     <!-- man begin SYNOPSIS strip -->
     strip [<samp><span class="option">-F</span></samp> <var>bfdname</var> |<samp><span class="option">--target=</span></samp><var>bfdname</var>]
           [<samp><span class="option">-I</span></samp> <var>bfdname</var> |<samp><span class="option">--input-target=</span></samp><var>bfdname</var>]
           [<samp><span class="option">-O</span></samp> <var>bfdname</var> |<samp><span class="option">--output-target=</span></samp><var>bfdname</var>]
           [<samp><span class="option">-s</span></samp>|<samp><span class="option">--strip-all</span></samp>]
           [<samp><span class="option">-S</span></samp>|<samp><span class="option">-g</span></samp>|<samp><span class="option">-d</span></samp>|<samp><span class="option">--strip-debug</span></samp>]
           [<samp><span class="option">--strip-dwo</span></samp>]
           [<samp><span class="option">-K</span></samp> <var>symbolname</var>|<samp><span class="option">--keep-symbol=</span></samp><var>symbolname</var>]
           [<samp><span class="option">-M</span></samp>|<samp><span class="option">--merge-notes</span></samp>][<samp><span class="option">--no-merge-notes</span></samp>]
           [<samp><span class="option">-N</span></samp> <var>symbolname</var> |<samp><span class="option">--strip-symbol=</span></samp><var>symbolname</var>]
           [<samp><span class="option">-w</span></samp>|<samp><span class="option">--wildcard</span></samp>]
           [<samp><span class="option">-x</span></samp>|<samp><span class="option">--discard-all</span></samp>] [<samp><span class="option">-X</span></samp> |<samp><span class="option">--discard-locals</span></samp>]
           [<samp><span class="option">-R</span></samp> <var>sectionname</var> |<samp><span class="option">--remove-section=</span></samp><var>sectionname</var>]
           [<samp><span class="option">--remove-relocations=</span></samp><var>sectionpattern</var>]
           [<samp><span class="option">-o</span></samp> <var>file</var>] [<samp><span class="option">-p</span></samp>|<samp><span class="option">--preserve-dates</span></samp>]
           [<samp><span class="option">-D</span></samp>|<samp><span class="option">--enable-deterministic-archives</span></samp>]
           [<samp><span class="option">-U</span></samp>|<samp><span class="option">--disable-deterministic-archives</span></samp>]
           [<samp><span class="option">--keep-file-symbols</span></samp>]
           [<samp><span class="option">--only-keep-debug</span></samp>]
           [<samp><span class="option">-v</span></samp> |<samp><span class="option">--verbose</span></samp>] [<samp><span class="option">-V</span></samp>|<samp><span class="option">--version</span></samp>]
           [<samp><span class="option">--help</span></samp>] [<samp><span class="option">--info</span></samp>]
           <var>objfile</var>...
     <!-- man end -->
</pre>
   <!-- man begin DESCRIPTION strip -->
   <p><span class="sc">gnu</span> <samp><span class="command">strip</span></samp> discards all symbols from object files
<var>objfile</var>.  The list of object files may include archives. 
At least one object file must be given.

   <p><samp><span class="command">strip</span></samp> modifies the files named in its argument,
rather than writing modified copies under different names.

<!-- man end -->
<!-- man begin OPTIONS strip -->
     <dl>
<dt><samp><span class="env">-F </span><var>bfdname</var></samp><dt><samp><span class="env">--target=</span><var>bfdname</var></samp><dd>Treat the original <var>objfile</var> as a file with the object
code format <var>bfdname</var>, and rewrite it in the same format. 
See <a href="Target-Selection.html#Target-Selection">Target Selection</a>, for more information.

     <br><dt><samp><span class="env">--help</span></samp><dd>Show a summary of the options to <samp><span class="command">strip</span></samp> and exit.

     <br><dt><samp><span class="env">--info</span></samp><dd>Display a list showing all architectures and object formats available.

     <br><dt><samp><span class="env">-I </span><var>bfdname</var></samp><dt><samp><span class="env">--input-target=</span><var>bfdname</var></samp><dd>Treat the original <var>objfile</var> as a file with the object
code format <var>bfdname</var>. 
See <a href="Target-Selection.html#Target-Selection">Target Selection</a>, for more information.

     <br><dt><samp><span class="env">-O </span><var>bfdname</var></samp><dt><samp><span class="env">--output-target=</span><var>bfdname</var></samp><dd>Replace <var>objfile</var> with a file in the output format <var>bfdname</var>. 
See <a href="Target-Selection.html#Target-Selection">Target Selection</a>, for more information.

     <br><dt><samp><span class="env">-R </span><var>sectionname</var></samp><dt><samp><span class="env">--remove-section=</span><var>sectionname</var></samp><dd>Remove any section named <var>sectionname</var> from the output file, in
addition to whatever sections would otherwise be removed.  This
option may be given more than once.  Note that using this option
inappropriately may make the output file unusable.  The wildcard
character &lsquo;<samp><span class="samp">*</span></samp>&rsquo; may be given at the end of <var>sectionname</var>.  If
so, then any section starting with <var>sectionname</var> will be removed.

     <p>If the first character of <var>sectionpattern</var> is the exclamation
point (!) then matching sections will not be removed even if an
earlier use of <samp><span class="option">--remove-section</span></samp> on the same command line
would otherwise remove it.  For example:

     <pre class="smallexample">            --remove-section=.text.* --remove-section=!.text.foo
</pre>
     <p>will remove all sections matching the pattern '.text.*', but will not
remove the section '.text.foo'.

     <br><dt><samp><span class="env">--remove-relocations=</span><var>sectionpattern</var></samp><dd>Remove relocations from the output file for any section matching
<var>sectionpattern</var>.  This option may be given more than once.  Note
that using this option inappropriately may make the output file
unusable.  Wildcard characters are accepted in <var>sectionpattern</var>. 
For example:

     <pre class="smallexample">            --remove-relocations=.text.*
</pre>
     <p>will remove the relocations for all sections matching the patter
'.text.*'.

     <p>If the first character of <var>sectionpattern</var> is the exclamation
point (!) then matching sections will not have their relocation
removed even if an earlier use of <samp><span class="option">--remove-relocations</span></samp> on the
same command line would otherwise cause the relocations to be removed. 
For example:

     <pre class="smallexample">            --remove-relocations=.text.* --remove-relocations=!.text.foo
</pre>
     <p>will remove all relocations for sections matching the pattern
'.text.*', but will not remove relocations for the section
'.text.foo'.

     <br><dt><samp><span class="env">-s</span></samp><dt><samp><span class="env">--strip-all</span></samp><dd>Remove all symbols.

     <br><dt><samp><span class="env">-g</span></samp><dt><samp><span class="env">-S</span></samp><dt><samp><span class="env">-d</span></samp><dt><samp><span class="env">--strip-debug</span></samp><dd>Remove debugging symbols only.

     <br><dt><samp><span class="env">--strip-dwo</span></samp><dd>Remove the contents of all DWARF .dwo sections, leaving the
remaining debugging sections and all symbols intact. 
See the description of this option in the <samp><span class="command">objcopy</span></samp> section
for more information.

     <br><dt><samp><span class="env">--strip-unneeded</span></samp><dd>Remove all symbols that are not needed for relocation processing.

     <br><dt><samp><span class="env">-K </span><var>symbolname</var></samp><dt><samp><span class="env">--keep-symbol=</span><var>symbolname</var></samp><dd>When stripping symbols, keep symbol <var>symbolname</var> even if it would
normally be stripped.  This option may be given more than once.

     <br><dt><samp><span class="env">-M</span></samp><dt><samp><span class="env">--merge-notes</span></samp><dt><samp><span class="env">--no-merge-notes</span></samp><dd>For ELF files, attempt (or do not attempt) to reduce the size of any
SHT_NOTE type sections by removing duplicate notes.  The default is to
attempt this reduction unless stripping debug or DWO information.

     <br><dt><samp><span class="env">-N </span><var>symbolname</var></samp><dt><samp><span class="env">--strip-symbol=</span><var>symbolname</var></samp><dd>Remove symbol <var>symbolname</var> from the source file. This option may be
given more than once, and may be combined with strip options other than
<samp><span class="option">-K</span></samp>.

     <br><dt><samp><span class="env">-o </span><var>file</var></samp><dd>Put the stripped output in <var>file</var>, rather than replacing the
existing file.  When this argument is used, only one <var>objfile</var>
argument may be specified.

     <br><dt><samp><span class="env">-p</span></samp><dt><samp><span class="env">--preserve-dates</span></samp><dd>Preserve the access and modification dates of the file.

     <br><dt><samp><span class="env">-D</span></samp><dt><samp><span class="env">--enable-deterministic-archives</span></samp><dd><a name="index-deterministic-archives-137"></a><a name="index-g_t_002d_002denable_002ddeterministic_002darchives-138"></a>Operate in <em>deterministic</em> mode.  When copying archive members
and writing the archive index, use zero for UIDs, GIDs, timestamps,
and use consistent file modes for all files.

     <p>If <samp><span class="file">binutils</span></samp> was configured with
<samp><span class="option">--enable-deterministic-archives</span></samp>, then this mode is on by default. 
It can be disabled with the &lsquo;<samp><span class="samp">-U</span></samp>&rsquo; option, below.

     <br><dt><samp><span class="env">-U</span></samp><dt><samp><span class="env">--disable-deterministic-archives</span></samp><dd><a name="index-deterministic-archives-139"></a><a name="index-g_t_002d_002denable_002ddeterministic_002darchives-140"></a>Do <em>not</em> operate in <em>deterministic</em> mode.  This is the
inverse of the <samp><span class="option">-D</span></samp> option, above: when copying archive members
and writing the archive index, use their actual UID, GID, timestamp,
and file mode values.

     <p>This is the default unless <samp><span class="file">binutils</span></samp> was configured with
<samp><span class="option">--enable-deterministic-archives</span></samp>.

     <br><dt><samp><span class="env">-w</span></samp><dt><samp><span class="env">--wildcard</span></samp><dd>Permit regular expressions in <var>symbolname</var>s used in other command
line options.  The question mark (?), asterisk (*), backslash (\) and
square brackets ([]) operators can be used anywhere in the symbol
name.  If the first character of the symbol name is the exclamation
point (!) then the sense of the switch is reversed for that symbol. 
For example:

     <pre class="smallexample">            -w -K !foo -K fo*
</pre>
     <p>would cause strip to only keep symbols that start with the letters
&ldquo;fo&rdquo;, but to discard the symbol &ldquo;foo&rdquo;.

     <br><dt><samp><span class="env">-x</span></samp><dt><samp><span class="env">--discard-all</span></samp><dd>Remove non-global symbols.

     <br><dt><samp><span class="env">-X</span></samp><dt><samp><span class="env">--discard-locals</span></samp><dd>Remove compiler-generated local symbols. 
(These usually start with &lsquo;<samp><span class="samp">L</span></samp>&rsquo; or &lsquo;<samp><span class="samp">.</span></samp>&rsquo;.)

     <br><dt><samp><span class="env">--keep-file-symbols</span></samp><dd>When stripping a file, perhaps with <samp><span class="option">--strip-debug</span></samp> or
<samp><span class="option">--strip-unneeded</span></samp>, retain any symbols specifying source file names,
which would otherwise get stripped.

     <br><dt><samp><span class="env">--only-keep-debug</span></samp><dd>Strip a file, emptying the contents of any sections that would not be
stripped by <samp><span class="option">--strip-debug</span></samp> and leaving the debugging sections
intact.  In ELF files, this preserves all the note sections in the
output as well.

     <p>Note - the section headers of the stripped sections are preserved,
including their sizes, but the contents of the section are discarded. 
The section headers are preserved so that other tools can match up the
debuginfo file with the real executable, even if that executable has
been relocated to a different address space.

     <p>The intention is that this option will be used in conjunction with
<samp><span class="option">--add-gnu-debuglink</span></samp> to create a two part executable.  One a
stripped binary which will occupy less space in RAM and in a
distribution and the second a debugging information file which is only
needed if debugging abilities are required.  The suggested procedure
to create these files is as follows:

          <ol type=1 start=1>
<li>Link the executable as normal.  Assuming that it is called
<code>foo</code> then... 
<li>Run <code>objcopy --only-keep-debug foo foo.dbg</code> to
create a file containing the debugging info. 
<li>Run <code>objcopy --strip-debug foo</code> to create a
stripped executable. 
<li>Run <code>objcopy --add-gnu-debuglink=foo.dbg foo</code>
to add a link to the debugging info into the stripped executable.
          </ol>

     <p>Note&mdash;the choice of <code>.dbg</code> as an extension for the debug info
file is arbitrary.  Also the <code>--only-keep-debug</code> step is
optional.  You could instead do this:

          <ol type=1 start=1>
<li>Link the executable as normal. 
<li>Copy <code>foo</code> to <code>foo.full</code>
<li>Run <code>strip --strip-debug foo</code>
<li>Run <code>objcopy --add-gnu-debuglink=foo.full foo</code>
          </ol>

     <p>i.e., the file pointed to by the <samp><span class="option">--add-gnu-debuglink</span></samp> can be the
full executable.  It does not have to be a file created by the
<samp><span class="option">--only-keep-debug</span></samp> switch.

     <p>Note&mdash;this switch is only intended for use on fully linked files.  It
does not make sense to use it on object files where the debugging
information may be incomplete.  Besides the gnu_debuglink feature
currently only supports the presence of one filename containing
debugging information, not multiple filenames on a one-per-object-file
basis.

     <br><dt><samp><span class="env">-V</span></samp><dt><samp><span class="env">--version</span></samp><dd>Show the version number for <samp><span class="command">strip</span></samp>.

     <br><dt><samp><span class="env">-v</span></samp><dt><samp><span class="env">--verbose</span></samp><dd>Verbose output: list all object files modified.  In the case of
archives, &lsquo;<samp><span class="samp">strip -v</span></samp>&rsquo; lists all members of the archive. 
</dl>

<!-- man end -->
   </body></html>