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patchelf - Modify ELF files

patchelf OPTION FILE ...

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.

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

Uses the given page size instead of the default.
Change the dynamic loader ("ELF interpreter") of executable given to INTERPRETER.
Prints the ELF interpreter of the executable.
Prints DT_SONAME entry of .dynamic section. Raises an error if DT_SONAME doesn't exist.
Sets DT_SONAME entry of a library to SONAME.
Change the DT_RUNPATH of the executable or library to RUNPATH.
Add RUNPATH to the existing DT_RUNPATH of the executable or library.
Removes the DT_RPATH or DT_RUNPATH entry of the executable or library.
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".

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.
Prints the DT_RUNPATH or DT_RPATH for an executable or library.
Forces the use of the obsolete DT_RPATH in the file instead of DT_RUNPATH. By default DT_RPATH is converted to DT_RUNPATH.
Adds a declared dependency on a dynamic library (DT_NEEDED). This option can be given multiple times.
Replaces a declared dependency on a dynamic library with another one (DT_NEEDED). This option can be given multiple times.
Removes a declared dependency on LIBRARY (DT_NEEDED entry). This option can be given multiple times.
Prints all DT_NEEDED entries of the executable.
Marks the object so that the search for dependencies of this object will ignore any default library search paths.
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".
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.
Set the output file name. If not specified, the input will be modified in place.
Prints details of the changes made to the input file.
Shows the version of patchelf.

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

Eelco Dolstra <e.dolstra@tudelft.nl>

elf(5), ld.so(8)

JUNE 2010 PATCHELF