READELF(1)
β¨ NAME β¨
readelf β display information about ELF files. GNU Development Tools bestie edition, obviously π
π¦ SYNOPSIS π¦
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...
πΈ DESCRIPTION πΈ
Okay so readelf displays information about one or more ELF format object files. The options control what particular information to display β like, pick your vibe and it shows you that part.
elffile... are the object files to be examined. Both 32-bit and 64-bit ELF files are supported, and so are archives containing ELF files. Versatile icon behavior, no cap.
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. Independent main character energy β¨
π OPTIONS π
The long and short forms of options, shown here as alternatives, are equivalent. And bestie, at least one option besides -v or -H must be given. Not me showing up with only -v or -H and expecting the whole tea π
-a,--allβ Equivalent to specifying--file-header,--program-headers,--sections,--symbols,--relocs,--dynamic,--notes,--version-info,--arch-specific,--unwind,--section-groupsand--histogram.
π Note β 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-headerβ Displays the information contained in the ELF header at the start of the file.-l,--program-headers,--segmentsβ Displays the information contained in the file's segment headers, if it has any.--quietβ Suppress the"no symbols"diagnostic. Peace and quiet, lowkey iconic.-S,--sections,--section-headersβ Displays the information contained in the file's section headers, if it has any.-g,--section-groupsβ Displays the information contained in the file's section groups, if it has any.-t,--section-detailsβ Displays the detailed section information. Implies-S.-s,--symbols,--symsβ 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 examplefoo@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 examplefoo@@VER_2.--dyn-symsβ 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--symsoption.--lto-symsβ Displays the contents of any LTO symbol tables in the file.--sym-base=[0|8|10|16]β Forces the size field of the symbol table to use the given base. Any unrecognized options will be treated as0.--sym-base=0represents the default and legacy behaviour. This will output sizes as decimal for numbers less than100000. For sizes100000and greater hexadecimal notation will be used with a0xprefix.--sym-base=8will give the symbol sizes in octal.--sym-base=10will always give the symbol sizes in decimal.--sym-base=16will always give the symbol sizes in hexadecimal with a0xprefix.-C,--demangle[=style]β 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-demangleβ Do not demangle low-level symbol names. This is the default.--recurse-limit,--no-recurse-limit,--recursion-limit,--no-recursion-limitβ 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 to2048levels 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. That part is serious, bestie π
-U [d|i|l|e|x|h],--unicode=[default|invalid|locale|escape|hex|highlight]β Controls the display of non-ASCII characters in identifier names. The default (--unicode=localeor--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=invalidoption is used then they are displayed as a sequence of hex bytes, enclosed in curly parenthesis characters.
Using the --unicode=escape option will display the characters 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 highlight 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-infoβ 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-infoβ Disables the effect of the--extra-sym-infooption. This is the default.-e,--headersβ Display all the headers in the file. Equivalent to-h -l -S.-n,--notesβ Displays the contents of the NOTE segments and/or sections, if any.-r,--relocsβ Displays the contents of the file's relocation section, if it has one.-u,--unwindβ 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_framessection using the--debug-dump=framesor--debug-dump=frames-interpoptions.-d,--dynamicβ Displays the contents of the file's dynamic section, if it has one.-V,--version-infoβ Displays the contents of the version sections in the file, if they exist.-A,--arch-specificβ Displays architecture-specific information in the file, if there is any.-D,--use-dynamicβ When displaying symbols, this option makesreadelfuse 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-checksβ 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>β Displays the contents of the indicated section as 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>β Displays the contents of the indicated section as 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>β bestie, this one dumps the section you point at as printable strings πβ¨. 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. You can repeat this option multiple times on the command line to request multiple string dumps. Slay.-j <number or name>,--display-sectionβ displays the contents of the indicated section according to its section header type. Sections containing relocations get displayed as if the--relocationsoption had been used, sections containing symbols get displayed as if the--symsoption 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 to request multiple section dumps. Iconic behavior.-z,--decompressβ requests that the section(s) being dumped by thex,Rorpoptions are decompressed before being displayed π . If the section(s) are not compressed, then they are displayed as is. No drama.-c,--archive-indexβ displays the file symbol index information contained in the header part of binary archives ποΈ. Performs the same function as thetcommand toar, but without using the BFD library. Periodt.-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]β displays the contents of the DWARF debug sections in the file, if any are present π§β¨. 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,=abbrevβ displays the contents of the.debug_abbrevsection.A,=addrβ displays the contents of the.debug_addrsection.c,=cu_indexβ displays the contents of the.debug_cu_indexand/or.debug_tu_indexsections.f,=framesβ displays the raw contents of a.debug_framesection.F,=frames-interpβ displays the interpreted contents of a.debug_framesection.g,=gdb_indexβ displays the contents of the.gdb_indexand/or.debug_namessections.i,=infoβ displays the contents of the.debug_infosection. Note: the output from this option can also be restricted by the use of the--dwarf-depthand--dwarf-startoptions.k,=linksβ displays the contents of the.gnu_debuglink,.gnu_debugaltlinkand.debug_supsections, if any of them are present. Also displays any links to separate dwarf object files (dwo), if they are specified by theDW_AT_GNU_dwo_nameorDW_AT_dwo_nameattributes in the.debug_infosection.K,=follow-linksβ displays the contents of any selected debug sections that are found in linked, separate debug info file(s) π«Ά. 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
Ndebug option. The default can be chosen when configuring the binutils via the--enable-follow-debug-links=yesor--enable-follow-debug-links=nooptions. 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_URLSenvironment variable. This could take some time to resolve π. This behaviour can be disabled via the=do-not-use-debuginfoddebug option.
N,=no-follow-linksβ disables the following of links to separate debug info files.D,=use-debuginfodβ enables contacting debuginfod servers if there is a need to follow debug links. This is the default behaviour.E,=do-not-use-debuginfodβ disables contacting debuginfod servers when there is a need to follow debug links.l,=rawlineβ displays the contents of the.debug_linesection in a raw format.L,=decodedlineβ displays the interpreted contents of the.debug_linesection.m,=macroβ displays the contents of the.debug_macroand/or.debug_macinfosections.o,=locβ displays the contents of the.debug_locand/or.debug_loclistssections.O,=str-offsetsβ displays the contents of the.debug_str_offsetssection.p,=pubnamesβ displays the contents of the.debug_pubnamesand/or.debug_gnu_pubnamessections.r,=arangesβ displays the contents of the.debug_arangessection.R,=Rangesβ displays the contents of the.debug_rangesand/or.debug_rnglistssections.s,=strβ displays the contents of the.debug_str,.debug_line_strand/or.debug_str_offsetssections.t,=pubtypeβ displays the contents of the.debug_pubtypesand/or.debug_gnu_pubtypessections.T,=trace_arangesβ displays the contents of the.trace_arangessection.u,=trace_abbrevβ displays the contents of the.trace_abbrevsection.U,=trace_infoβ displays the contents of the.trace_infosection.
Note: displaying the contents of.debug_static_funcs,.debug_static_varsanddebug_weaknamessections is not currently supported. π
--dwarf-depth=nβ limits the dump of the.debug_infosection tonchildren. This is only useful with--debug-dump=info. The default is to print all DIEs; the special value0fornwill also have this effect. With a non-zero value forn, DIEs at or deeper thannlevels will not be printed. The range fornis zero-based.--dwarf-start=nβ prints only DIEs beginning with the DIE numberedn. 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 numberedn. Only siblings and children of the specified DIE will be printed. This can be used in conjunction with--dwarf-depth.-P,--process-linksβ displays the contents of non-debug sections found in separate debuginfo files that are linked to the main file. This option automatically implies the-wKoption, and only sections requested by other command line options will be displayed.--ctf[=section]β displays 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 byld.--ctf-parent=memberβ 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 thectf_link_set_memb_name_changerfunction 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-parentcan be used to specify the name used for the parent.--ctf-parent-section=sectionβ 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. Itβs also convenient to inspect CTF written out as multiple raw files to compose them withobjcopy, which can put them in different ELF sections but not in different members of a single CTF dict.--ctf-symbols=section,--ctf-strings=sectionβ specify the name of another section from which the CTF file can inherit strings and symbols. By default, the.symtaband its linked string table are used. If either of--ctf-symbolsor--ctf-stringsis specified, the other must be specified as well.-I,--histogramβ displays a histogram of bucket list lengths when displaying the contents of the symbol tables.-v,--versionβ displays the version number ofreadelf.-W,--wideβ donβt break output lines to fit into 80 columns. By defaultreadelfbreaks section header and segment listing lines for 64-bit ELF files, so that they fit into 80 columns. This option causesreadelfto print each section header resp. each segment on a single line, which is far more readable on terminals wider than 80 columns.-T,--silent-truncationβ normally whenreadelfis 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 ofreadelf(prior to release 2.35).-H,--helpβ displays the command-line options understood byreadelf.@fileβ reads command-line options fromfile. The options read are inserted in place of the original@fileoption. Iffiledoes not exist, or cannot be read, then the option will be treated literally, and not removed.
Ok so real quick, before we dip β a little more about how the @file situation actually works, because the details are lowkey important π
Options inside the file are separated by whitespace. That's the whole rule, bestie β spaces, tabs, whatever whitespace, it's a vibe check.
But what if you need a whitespace character inside an option? Easy β just wrap the entire option in either single or double quotes. 'like this' or "like this". Both slay.
And what if you need any character (yes, even a backslash, we're being generous) included as itself? Just prefix the character you want with a backslash. Escape it, babes.
π Plot twist: the file may itself contain additional @file options, and any such options will be processed recursively. It's files all the way down. Inception-core. Be careful not to make a loop that ate itself, iykyk π
π«Ά SEE ALSO
objdump(1)β the other iconic binutils bestie, go say hi- and the Info entries for
binutils, for when you want the full lore β¨
π COPYRIGHT
Copyright (c) 1991-2025 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".
So yeah. Legal said what it said, and honestly? Fair. Read the license, it's giving required reading πβ¨
And that's the whole page, bestie!! ππ You officially know readelf now. Go disassemble something and be the main character of your own binary π¦
This little masterpiece is from binutils-2.45.1, dated 2026-01-23 β so yes, she's fresh, she's current, she's iconic. Periodt. π π
π¦ where this page comes from
- arch rolling: lm32-elf-binutils 2.45.1-1 Β· GPL
- π girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on : a language model's rewrite of the original, under its terms