jammy (1) readelf.1.gz

Provided by: binutils-common_2.38-4ubuntu2.6_amd64 bug

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]
               [-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>]
               [-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]
               [-P|--process-links]
               [--dwarf-depth=n]
               [--dwarf-start=n]
               [--ctf=section]
               [--ctf-parent=section]
               [--ctf-symbols=section]
               [--ctf-strings=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.

       -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.

       -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.

       -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.

       -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.

           "N"
           "=no-follow-links"
               Disables the following of links to separate debug info files.

           "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-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.

SEE ALSO

       objdump(1), and the Info entries for binutils.

       Copyright (c) 1991-2022 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".