# readelf

## NAME



           readelf - display information about ELF files
    


## SYNOPSIS



           readelf [**-a** |**--all**]
                   [**-h** |**--file-header**]
                   [**-l** |**--program-headers** |**--segments**]
                   [**-S** |**--section-headers** |**--sections**]
                   [**-g** |**--section-groups**]
                   [**-t** |**--section-details**]
                   [**-e** |**--headers**]
                   [**-s** |**--syms** |**--symbols**]
                   [**--dyn-syms** |**--lto-syms**]
                   [**--sym-base=[0|8|10|16]**]
                   [**--demangle** _=style_ |**--no-demangle**]
                   [**--quiet**]
                   [**--recurse-limit** |**--no-recurse-limit**]
                   [**-U** _method_ |**--unicode=**_method_]
                   [**-X** |**--extra-sym-info** |**--no-extra-sym-info**]
                   [**-n** |**--notes**]
                   [**-r** |**--relocs**]
                   [**-u** |**--unwind**]
                   [**-d** |**--dynamic**]
                   [**-V** |**--version-info**]
                   [**-A** |**--arch-specific**]
                   [**-D** |**--use-dynamic**]
                   [**-L** |**--lint** |**--enable-checks**]
                   [**-x** <number or name>|**--hex-dump=** <number or name>]
                   [**-p** <number or name>|**--string-dump=** <number or name>]
                   [**-R** <number or name>|**--relocated-dump=** <number or name>]
                   [**-j** <number or name>|**--display-section=** <number or name>]
                   [**-z** |**--decompress**]
                   [**-c** |**--archive-index**]
                   [**-w[lLiaprmfFsoORtUuTgAck]** |
                    **--debug-dump**[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links]]
                   [**-wK** |**--debug-dump=follow-links**]
                   [**-wN** |**--debug-dump=no-follow-links**]
                   [**-wD** |**--debug-dump=use-debuginfod**]
                   [**-wE** |**--debug-dump=do-not-use-debuginfod**]
                   [**-P** |**--process-links**]
                   [**--dwarf-depth=**_n_]
                   [**--dwarf-start=**_n_]
                   [**--ctf=**_section_]
                   [**--ctf-parent=**_section_]
                   [**--ctf-symbols=**_section_]
                   [**--ctf-strings=**_section_]
                   [**--sframe=**_section_]
                   [**-I** |**--histogram**]
                   [**-v** |**--version**]
                   [**-W** |**--wide**]
                   [**-T** |**--silent-truncation**]
                   [**-H** |**--help**]
                   _elffile_...
    


## DESCRIPTION



           **readelf** displays information about one or more ELF format object
           files.  The options control what particular information to
           display.
    
           _elffile_... are the object files to be examined.  32-bit and 64-bit
           ELF files are supported, as are archives containing ELF files.
    
           This program performs a similar function to **objdump** but it goes
           into more detail and it exists independently of the BFD library,
           so if there is a bug in BFD then readelf will not be affected.
    


## OPTIONS



           The long and short forms of options, shown here as alternatives,
           are equivalent.  At least one option besides **-v** or **-H** must be
           given.
    
           **-a**
           **--all**
               Equivalent to specifying **--file-header** , **--program-headers** ,
               **--sections** , **--symbols** , **--relocs** , **--dynamic** , **--notes** ,
               **--version-info** , **--arch-specific** , **--unwind** , **--section-groups**
               and **--histogram**.
    
               Note - this option does not enable **--use-dynamic** itself, so if
               that option is not present on the command line then dynamic
               symbols and dynamic relocs will not be displayed.
    
           **-h**
           **--file-header**
               Displays the information contained in the ELF header at the
               start of the file.
    
           **-l**
           **--program-headers**
           **--segments**
               Displays the information contained in the file's segment
               headers, if it has any.
    
           **--quiet**
               Suppress "no symbols" diagnostic.
    
           **-S**
           **--sections**
           **--section-headers**
               Displays the information contained in the file's section
               headers, if it has any.
    
           **-g**
           **--section-groups**
               Displays the information contained in the file's section
               groups, if it has any.
    
           **-t**
           **--section-details**
               Displays the detailed section information. Implies **-S**.
    
           **-s**
           **--symbols**
           **--syms**
               Displays the entries in symbol table section of the file, if
               it has one.  If a symbol has version information associated
               with it then this is displayed as well.  The version string is
               displayed as a suffix to the symbol name, preceded by an @
               character.  For example **foo@VER_1**.  If the version is the
               default version to be used when resolving unversioned
               references to the symbol then it is displayed as a suffix
               preceded by two @ characters.  For example **foo@@VER_2**.
    
           **--dyn-syms**
               Displays the entries in dynamic symbol table section of the
               file, if it has one.  The output format is the same as the
               format used by the **--syms** option.
    
           **--lto-syms**
               Displays the contents of any LTO symbol tables in the file.
    
           **--sym-base=[0|8|10|16]**
               Forces the size field of the symbol table to use the given
               base.  Any unrecognized options will be treated as **0**.
               **--sym-base=0** represents the default and legacy behaviour.
               This will output sizes as decimal for numbers less than
               100000.  For sizes 100000 and greater hexadecimal notation
               will be used with a 0x prefix.  **--sym-base=8** will give the
               symbol sizes in octal.  **--sym-base=10** will always give the
               symbol sizes in decimal.  **--sym-base=16** will always give the
               symbol sizes in hexadecimal with a 0x prefix.
    
           **-C**
           **--demangle[=**_style_**]**
               Decode (_demangle_) low-level symbol names into user-level
               names.  This makes C++ function names readable.  Different
               compilers have different mangling styles.  The optional
               demangling style argument can be used to choose an appropriate
               demangling style for your compiler.
    
           **--no-demangle**
               Do not demangle low-level symbol names.  This is the default.
    
           **--recurse-limit**
           **--no-recurse-limit**
           **--recursion-limit**
           **--no-recursion-limit**
               Enables or disables a limit on the amount of recursion
               performed whilst demangling strings.  Since the name mangling
               formats allow for an infinite level of recursion it is
               possible to create strings whose decoding will exhaust the
               amount of stack space available on the host machine,
               triggering a memory fault.  The limit tries to prevent this
               from happening by restricting recursion to 2048 levels of
               nesting.
    
               The default is for this limit to be enabled, but disabling it
               may be necessary in order to demangle truly complicated names.
               Note however that if the recursion limit is disabled then
               stack exhaustion is possible and any bug reports about such an
               event will be rejected.
    
           **-U** _[d|i|l|e|x|h]_
           **--unicode=[default|invalid|locale|escape|hex|highlight]**
               Controls the display of non-ASCII characters in identifier
               names.  The default (**--unicode=locale** or **--unicode=default**) is
               to treat them as multibyte characters and display them in the
               current locale.  All other versions of this option treat the
               bytes as UTF-8 encoded values and attempt to interpret them.
               If they cannot be interpreted or if the **--unicode=invalid**
               option is used then they are displayed as a sequence of hex
               bytes, encloses in curly parethesis characters.
    
               Using the **--unicode=escape** option will display the characters
               as as unicode escape sequences (_\uxxxx_).  Using the
               **--unicode=hex** will display the characters as hex byte
               sequences enclosed between angle brackets.
    
               Using the **--unicode=highlight** will display the characters as
               unicode escape sequences but it will also highlighted them in
               red, assuming that colouring is supported by the output
               device.  The colouring is intended to draw attention to the
               presence of unicode sequences when they might not be expected.
    
           **-X**
           **--extra-sym-info**
               When displaying details of symbols, include extra information
               not normally presented.  Currently this just adds the name of
               the section referenced by the symbol's index field, if there
               is one.  In the future more information may be displayed when
               this option is enabled.
    
               Enabling this option effectively enables the **--wide** option as
               well, at least when displaying symbol information.
    
           **--no-extra-sym-info**
               Disables the effect of the **--extra-sym-info** option.  This is
               the default.
    
           **-e**
           **--headers**
               Display all the headers in the file.  Equivalent to **-h -l -S**.
    
           **-n**
           **--notes**
               Displays the contents of the NOTE segments and/or sections, if
               any.
    
           **-r**
           **--relocs**
               Displays the contents of the file's relocation section, if it
               has one.
    
           **-u**
           **--unwind**
               Displays the contents of the file's unwind section, if it has
               one.  Only the unwind sections for IA64 ELF files, as well as
               ARM unwind tables (".ARM.exidx" / ".ARM.extab") are currently
               supported.  If support is not yet implemented for your
               architecture you could try dumping the contents of the
               _.eh_frames_ section using the **--debug-dump=frames** or
               **--debug-dump=frames-interp** options.
    
           **-d**
           **--dynamic**
               Displays the contents of the file's dynamic section, if it has
               one.
    
           **-V**
           **--version-info**
               Displays the contents of the version sections in the file, it
               they exist.
    
           **-A**
           **--arch-specific**
               Displays architecture-specific information in the file, if
               there is any.
    
           **-D**
           **--use-dynamic**
               When displaying symbols, this option makes **readelf** use the
               symbol hash tables in the file's dynamic section, rather than
               the symbol table sections.
    
               When displaying relocations, this option makes **readelf** display
               the dynamic relocations rather than the static relocations.
    
           **-L**
           **--lint**
           **--enable-checks**
               Displays warning messages about possible problems with the
               file(s) being examined.  If used on its own then all of the
               contents of the file(s) will be examined.  If used with one of
               the dumping options then the warning messages will only be
               produced for the things being displayed.
    
           **-x <number or name>**
           **--hex-dump= <number or name>**
               Displays the contents of the indicated section as a
               hexadecimal bytes.  A number identifies a particular section
               by index in the section table; any other string identifies all
               sections with that name in the object file.  This option can
               be repeated multiple times on the command line in order to
               request multiple hex dumps.
    
           **-R <number or name>**
           **--relocated-dump= <number or name>**
               Displays the contents of the indicated section as a
               hexadecimal bytes.  A number identifies a particular section
               by index in the section table; any other string identifies all
               sections with that name in the object file.  The contents of
               the section will be relocated before they are displayed.  This
               option can be repeated multiple times on the command line in
               order to request multiple relocated dumps.
    
           **-p <number or name>**
           **--string-dump= <number or name>**
               Displays the contents of the indicated section as printable
               strings.  A number identifies a particular section by index in
               the section table; any other string identifies all sections
               with that name in the object file.  This option can be
               repeated multiple times on the command line in order to
               request multiple string dumps.
    
           **-j <number or name>**
           **--display-section**
               Displays the contents of the indicated section according to
               its section header type.  Sections containing relocations will
               be displayed as if the **--relocations** option had been used,
               sections contains symbols will be displayed as if the **--syms**
               option had been used and so on.
    
               A number identifies a particular section by index in the
               section table; any other string identifies all sections with
               that name in the input file(s).
    
               This option can be repeated multiple times on the command line
               in order to request multiple section dumps.
    
           **-z**
           **--decompress**
               Requests that the section(s) being dumped by **x** , **R** or **p** options
               are decompressed before being displayed.  If the section(s)
               are not compressed then they are displayed as is.
    
           **-c**
           **--archive-index**
               Displays the file symbol index information contained in the
               header part of binary archives.  Performs the same function as
               the **t** command to **ar** , but without using the BFD library.
    
           **-w[lLiaprmfFsOoRtUuTgAckK]**
           **--debug-dump[=rawline,=decodedline,=info,=abbrev,=pubnames,=aranges,=macro,=frames,=frames-interp,=str,=str-offsets,=loc,=Ranges,=pubtypes,=trace_info,=trace_abbrev,=trace_aranges,=gdb_index,=addr,=cu_index,=links,=follow-links]**
               Displays the contents of the DWARF debug sections in the file,
               if any are present.  Compressed debug sections are
               automatically decompressed (temporarily) before they are
               displayed.  If one or more of the optional letters or words
               follows the switch then only those type(s) of data will be
               dumped.  The letters and words refer to the following
               information:
    
               "a"
               "=abbrev"
                   Displays the contents of the **.debug_abbrev** section.
    
               "A"
               "=addr"
                   Displays the contents of the **.debug_addr** section.
    
               "c"
               "=cu_index"
                   Displays the contents of the **.debug_cu_index** and/or
                   **.debug_tu_index** sections.
    
               "f"
               "=frames"
                   Display the raw contents of a **.debug_frame** section.
    
               "F"
               "=frames-interp"
                   Display the interpreted contents of a **.debug_frame**
                   section.
    
               "g"
               "=gdb_index"
                   Displays the contents of the **.gdb_index** and/or
                   **.debug_names** sections.
    
               "i"
               "=info"
                   Displays the contents of the **.debug_info** section.  Note:
                   the output from this option can also be restricted by the
                   use of the **--dwarf-depth** and **--dwarf-start** options.
    
               "k"
               "=links"
                   Displays the contents of the **.gnu_debuglink** ,
                   **.gnu_debugaltlink** and **.debug_sup** sections, if any of them
                   are present.  Also displays any links to separate dwarf
                   object files (dwo), if they are specified by the
                   DW_AT_GNU_dwo_name or DW_AT_dwo_name attributes in the
                   **.debug_info** section.
    
               "K"
               "=follow-links"
                   Display the contents of any selected debug sections that
                   are found in linked, separate debug info file(s).  This
                   can result in multiple versions of the same debug section
                   being displayed if it exists in more than one file.
    
                   In addition, when displaying DWARF attributes, if a form
                   is found that references the separate debug info file,
                   then the referenced contents will also be displayed.
    
                   Note - in some distributions this option is enabled by
                   default.  It can be disabled via the **N** debug option.  The
                   default can be chosen when configuring the binutils via
                   the **--enable-follow-debug-links=yes** or
                   **--enable-follow-debug-links=no** options.  If these are not
                   used then the default is to enable the following of debug
                   links.
    
                   Note - if support for the debuginfod protocol was enabled
                   when the binutils were built then this option will also
                   include an attempt to contact any debuginfod servers
                   mentioned in the _DEBUGINFOD_URLS_ environment variable.
                   This could take some time to resolve.  This behaviour can
                   be disabled via the **=do-not-use-debuginfod** debug option.
    
               "N"
               "=no-follow-links"
                   Disables the following of links to separate debug info
                   files.
    
               "D"
               "=use-debuginfod"
                   Enables contacting debuginfod servers if there is a need
                   to follow debug links.  This is the default behaviour.
    
               "E"
               "=do-not-use-debuginfod"
                   Disables contacting debuginfod servers when there is a
                   need to follow debug links.
    
               "l"
               "=rawline"
                   Displays the contents of the **.debug_line** section in a raw
                   format.
    
               "L"
               "=decodedline"
                   Displays the interpreted contents of the **.debug_line**
                   section.
    
               "m"
               "=macro"
                   Displays the contents of the **.debug_macro** and/or
                   **.debug_macinfo** sections.
    
               "o"
               "=loc"
                   Displays the contents of the **.debug_loc** and/or
                   **.debug_loclists** sections.
    
               "O"
               "=str-offsets"
                   Displays the contents of the **.debug_str_offsets** section.
    
               "p"
               "=pubnames"
                   Displays the contents of the **.debug_pubnames** and/or
                   **.debug_gnu_pubnames** sections.
    
               "r"
               "=aranges"
                   Displays the contents of the **.debug_aranges** section.
    
               "R"
               "=Ranges"
                   Displays the contents of the **.debug_ranges** and/or
                   **.debug_rnglists** sections.
    
               "s"
               "=str"
                   Displays the contents of the **.debug_str** , **.debug_line_str**
                   and/or **.debug_str_offsets** sections.
    
               "t"
               "=pubtype"
                   Displays the contents of the **.debug_pubtypes** and/or
                   **.debug_gnu_pubtypes** sections.
    
               "T"
               "=trace_aranges"
                   Displays the contents of the **.trace_aranges** section.
    
               "u"
               "=trace_abbrev"
                   Displays the contents of the **.trace_abbrev** section.
    
               "U"
               "=trace_info"
                   Displays the contents of the **.trace_info** section.
    
               Note: displaying the contents of **.debug_static_funcs** ,
               **.debug_static_vars** and **debug_weaknames** sections is not
               currently supported.
    
           **--dwarf-depth=**_n_
               Limit the dump of the ".debug_info" section to _n_ children.
               This is only useful with **--debug-dump=info**.  The default is to
               print all DIEs; the special value 0 for _n_ will also have this
               effect.
    
               With a non-zero value for _n_ , DIEs at or deeper than _n_ levels
               will not be printed.  The range for _n_ is zero-based.
    
           **--dwarf-start=**_n_
               Print only DIEs beginning with the DIE numbered _n_.  This is
               only useful with **--debug-dump=info**.
    
               If specified, this option will suppress printing of any header
               information and all DIEs before the DIE numbered _n_.  Only
               siblings and children of the specified DIE will be printed.
    
               This can be used in conjunction with **--dwarf-depth**.
    
           **-P**
           **--process-links**
               Display the contents of non-debug sections found in separate
               debuginfo files that are linked to the main file.  This option
               automatically implies the **-wK** option, and only sections
               requested by other command line options will be displayed.
    
           **--ctf[=**_section_**]**
               Display the contents of the specified CTF section.  CTF
               sections themselves contain many subsections, all of which are
               displayed in order.
    
               By default, display the name of the section named _.ctf_ , which
               is the name emitted by **ld**.
    
           **--ctf-parent=**_member_
               If the CTF section contains ambiguously-defined types, it will
               consist of an archive of many CTF dictionaries, all inheriting
               from one dictionary containing unambiguous types.  This member
               is by default named _.ctf_ , like the section containing it, but
               it is possible to change this name using the
               "ctf_link_set_memb_name_changer" function at link time.  When
               looking at CTF archives that have been created by a linker
               that uses the name changer to rename the parent archive
               member, **--ctf-parent** can be used to specify the name used for
               the parent.
    
           **--ctf-parent-section=**_section_
               This option lets you pick a completely different section for
               the CTF parent dictionary containing unambiguous types than
               for the child dictionaries that contain the ambiguous
               remainder.  The linker does not emit ELF objects structured
               like this, but some third-party linkers may.  It's also
               convenient to inspect CTF written out as multiple raw files to
               compose them with objcopy, which can put them in different ELF
               sections but not in different members of a single CTF dict.
    
           **--ctf-symbols=**_section_
           **--ctf-strings=**_section_
               Specify the name of another section from which the CTF file
               can inherit strings and symbols.  By default, the ".symtab"
               and its linked string table are used.
    
               If either of **--ctf-symbols** or **--ctf-strings** is specified, the
               other must be specified as well.
    
           **-I**
           **--histogram**
               Display a histogram of bucket list lengths when displaying the
               contents of the symbol tables.
    
           **-v**
           **--version**
               Display the version number of readelf.
    
           **-W**
           **--wide**
               Don't break output lines to fit into 80 columns. By default
               **readelf** breaks section header and segment listing lines for
               64-bit ELF files, so that they fit into 80 columns. This
               option causes **readelf** to print each section header resp. each
               segment one a single line, which is far more readable on
               terminals wider than 80 columns.
    
           **-T**
           **--silent-truncation**
               Normally when readelf is displaying a symbol name, and it has
               to truncate the name to fit into an 80 column display, it will
               add a suffix of "[...]" to the name.  This command line option
               disables this behaviour, allowing 5 more characters of the
               name to be displayed and restoring the old behaviour of
               readelf (prior to release 2.35).
    
           **-H**
           **--help**
               Display the command-line options understood by **readelf**.
    
           **@**_file_
               Read command-line options from _file_.  The options read are
               inserted in place of the original @_file_ option.  If _file_ does
               not exist, or cannot be read, then the option will be treated
               literally, and not removed.
    
               Options in _file_ are separated by whitespace.  A whitespace
               character may be included in an option by surrounding the
               entire option in either single or double quotes.  Any
               character (including a backslash) may be included by prefixing
               the character to be included with a backslash.  The _file_ may
               itself contain additional @_file_ options; any such options will
               be processed recursively.
    


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