NAME

       patchelf - Modify ELF files

SYNOPSIS

       patchelf OPTION FILE ...

DESCRIPTION

       PatchELF  is  a  simple  utility for modifying existing ELF executables and libraries.  It can change the
       dynamic loader ("ELF interpreter") of executables and change the RPATH of executables and libraries.

OPTIONS

       The single option given operates on each FILE, editing in place.

       Any option taking a string argument can also take a file by prefixing the argument with the @ symbol. See
       EXAMPLES

       --page-size SIZE
              Uses the given page size instead of the default.

       --set-interpreter INTERPRETER
              Change the dynamic loader ("ELF interpreter") of executable given to INTERPRETER.

       --print-interpreter
              Prints the ELF interpreter of the executable.

       --print-os-abi
              Prints the OS ABI of the executable (EI_OSABI field of an ELF file).

       --set-os-abi ABI
              Changes the OS ABI of the executable (EI_OSABI field of an ELF file).  The ABI parameter is pretty
              flexible. For example, you can specify it as a "Linux", "linux", or even "lInUx" - all those names
              will set EI_OSABI field of the ELF header to the value "3", which corresponds  to  Linux  OS  ABI.
              The same applies to other ABI names - System V, FreeBSD, Solaris, etc.

       --print-soname
              Prints DT_SONAME entry of .dynamic section.  Raises an error if DT_SONAME doesn't exist.

       --set-soname SONAME
              Sets DT_SONAME entry of a library to SONAME.

       --set-rpath RUNPATH
              Change the DT_RUNPATH of the executable or library to RUNPATH.

       --add-rpath RUNPATH
              Add RUNPATH to the existing DT_RUNPATH of the executable or library.

       --remove-rpath
              Removes the DT_RPATH or DT_RUNPATH entry of the executable or library.

       --shrink-rpath
              Remove from the DT_RUNPATH or DT_RPATH all directories that do not contain a library referenced by
              DT_NEEDED fields of the executable or library.

              For   instance,   if   an   executable   references   one   library   libfoo.so,   has   an  RPATH
              "/lib:/usr/lib:/foo/lib", and libfoo.so can only be found in /foo/lib, then the new RPATH will  be
              "/foo/lib".

       --allowed-rpath-prefixes PREFIXES
              Combined  with  the  "--shrink-rpath"  option,  this  can  be  used  for further rpath tuning. For
              instance, if an executable has an RPATH "/tmp/build-foo/.libs:/foo/lib", it is probably  desirable
              to keep the "/foo/lib" reference instead of the "/tmp" entry.

       --print-rpath
              Prints the DT_RUNPATH or DT_RPATH for an executable or library.

       --force-rpath
              Forces  the use of the obsolete DT_RPATH in the file instead of DT_RUNPATH. By default DT_RPATH is
              converted to DT_RUNPATH.

       --add-needed LIBRARY
              Adds a declared dependency on a dynamic library (DT_NEEDED).  This option can  be  given  multiple
              times.

       --replace-needed LIB_ORIG LIB_NEW
              Replaces a declared dependency on a dynamic library with another one (DT_NEEDED).  This option can
              be given multiple times.

       --remove-needed LIBRARY
              Removes  a  declared  dependency  on  LIBRARY (DT_NEEDED entry). This option can be given multiple
              times.

       --print-needed
              Prints all DT_NEEDED entries of the executable.

       --no-default-lib
              Marks the object so that the search for dependencies  of  this  object  will  ignore  any  default
              library search paths.

       --no-sort
              Do  not  sort program headers or section headers.  This is useful when debugging patchelf, because
              it makes it easier to read diffs of the output of "readelf -a".

       --add-debug-tag
              Adds DT_DEBUG tag to the .dynamic section if not yet present in an ELF object.  A  shared  library
              (-shared)  by default does not receive DT_DEBUG tag.  This means that when a shared library has an
              entry point (so that it can be run as  an  executable),  the  debugger  does  not  connect  to  it
              correctly and symbols are not resolved.

       --print-execstack
              Prints the state of the executable flag of the GNU_STACK program header, if present.

       --clear-execstack
              Clears the executable flag of the GNU_STACK program header, or adds a new header.

       --set-execstack
              Sets the executable flag of the GNU_STACK program header, or adds a new header.

       --rename-dynamic-symbols NAME_MAP_FILE
              Renames  dynamic  symbols.  The  name  map file should contain lines with the old and the new name
              separated by spaces like this:

              old_name new_name

              Symbol names do not contain version specifier that are also shown in  the  output  of  the  nm  -D
              command from binutils. So instead of the name write@GLIBC_2.2.5 it is just write.

       --output FILE
              Set the output file name.  If not specified, the input will be modified in place.

       --debug
              Prints details of the changes made to the input file.

       --version
              Shows the version of patchelf.

EXAMPLES

       To use the contents on an external file as a parameter:

              $ patchelf a.out --add-rpath @/tmp/generated-rpath.bin

       To  change  the  RPATH  of a binary. Note that $ORIGIN is a special symbol used by the loader, so must be
       quoted.

              patchelf --set-rpath '$ORIGIN/../lib64' a.out

AUTHOR

       Eelco Dolstra <e.dolstra@tudelft.nl>

SEE ALSO

       elf(5), ld.so(8)

PATCHELF                                            JULY 2022                                        PATCHELF(1)