Linux strip command

Updated: 03/13/2021 by Computer Hope
strip command

On Unix-like operating systems, the strip command discards symbols from compiled object files.

This page describes the Linux version of strip.

Description

strip is a GNU utility to "strip" symbols from object files. This is useful for minimizing their file size, streamlining them for distribution. It can also be useful for making it more difficult to reverse-engineer the compiled code.

The list of object files provided to strip may include archives and at least one object file must be provided. The object files themselves are modified by strip; new files are not created.

Syntax

strip [options] objfile [...]

Options

-F bfdname,
--target=bfdname		 Treat the original objfile as a file with the object code format bfdname, and rewrite it in the same format.
--help Show a summary of the options to strip and exit.
--info Display a list showing all architectures and object formats available.
-I bfdname,
--input-target=bfdname		 Treat the original objfile as a file with the object code format bfdname.
-O bfdname,
--output-target=bfdname		 Replace objfile with a file in the output format bfdname.
-R sectionname,
--remove-section=sectionname		 Remove any section named sectionname from the output file. This option may be given more than once. Note that using this option inappropriately may make the output file unusable.
-s, --strip-all Remove all symbols.
-g, -S, -d, --strip-debug Remove debugging symbols only.
--strip-dwo Remove the contents of all DWARF .dwo sections, leaving the remaining debugging sections and all symbols intact.
--strip-unneeded Remove all symbols that are not needed for relocation processing.
-K symbolname,
--keep-symbol=symbolname		 When stripping symbols, keep symbol symbolname even if it would normally be stripped. This option may be given more than once.
-N symbolname,
--strip-symbol=symbolname		 Remove symbol symbolname from the source file. This option may be given more than once, and may be combined with other strip options, except -K.
-o file Put the stripped output in file, rather than replacing the existing file. When this argument is used, only one objfile argument may be specified.
-p, --preserve-dates Preserve the access and modification dates of the file.
-D,
--enable-deterministic-archives		 Operate in deterministic mode. When copying archive members and writing the archive index, use zero for UIDs, GIDs, timestamps, and use consistent file modes for all files.
-w, --wildcard Permit regular expressions in symbolnames 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:

-w -K !foo -K fo*

would cause strip to only keep symbols that start with the letters "fo", but to discard the symbol "foo".
-x, --discard-all Remove non-global symbols.
-X, --discard-locals Remove compiler-generated local symbols. (These usually start with `L' or `.'.)
--keep-file-symbols When stripping a file, perhaps with --strip-debug or --strip-unneeded, retain any symbols specifying source file names, which would otherwise get stripped.
--only-keep-debug Strip a file, removing contents of any sections that would not be stripped by --strip-debug and leaving the debugging sections intact. In ELF files, this preserves all note sections in the output.

The intention is that this option will be used in conjunction with --add-gnu-debuglink 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 that is only needed if debugging abilities are required. The suggested procedure to create these files is as follows:
  1. Link the executable as normal. Assuming that it is called foo then...
  2. Run objcopy --only-keep-debug foo foo.dbg to create a file containing the debugging info.
  3. Run objcopy --strip-debug foo to create a stripped executable.
  4. Run objcopy --add-gnu-debuglink=foo.dbg foo to add a link to the debugging info into the stripped executable.
Note the choice of .dbg as an extension for the debug info file is arbitrary; it can be anything. Also, the --only-keep-debug step is optional. You could instead do this:
  1. Link the executable as normal.
  2. Copy foo to foo.full
  3. Run strip --strip-debug foo
  4. Run objcopy --add-gnu-debuglink=foo.full foo
In other words, the file pointed to by the --add-gnu-debuglink can be the full executable. It does not have to be a file created by the --only-keep-debug switch.

Note 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. The gnu_debuglink feature currently only supports the presence of one file name containing debugging information, not multiple file names on a one-per-object-file basis.
-V, --version Show the version number for strip.
-v, --verbose Verbose output: list all object files modified. In the case of archives, `strip -v' lists all members of the archive.

Examples

strip -s a.out

The above example would strip the symbol table from the executable file a.out.