READELF(1)
π NAME π
readelf β the star of the READELF(1) page in the GNU Development Tools manual β displays information about ELF files. She's literally built for this and she ate. π
β¨ SYNOPSIS β¨
Okay bestie, the synopsis is giving "so many flags, so little time," but every single bracket matters. Here it is, verbatim:
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|--debug-dump]
[-wa|--debug-dump=abbrev]
[-wA|--debug-dump=addr]
[-wr|--debug-dump=aranges]
[-wc|--debug-dump=cu_index]
[-wL|--debug-dump=decodedline]
[-wf|--debug-dump=frames]
[-wF|--debug-dump=frames-interp]
[-wg|--debug-dump=gdb_index]
[-wi|--debug-dump=info]
[-wk|--debug-dump=links]
[-wo|--debug-dump=loc]
[-wm|--debug-dump=macro]
[-wp|--debug-dump=pubnames]
[-wt|--debug-dump=pubtypes]
[-wR|--debug-dump=Ranges]
[-wl|--debug-dump=rawline]
[-ws|--debug-dump=str]
[-wO|--debug-dump=str-offsets]
[-wu|--debug-dump=trace_abbrev]
[-wT|--debug-dump=trace_aranges]
[-wU|--debug-dump=trace_info]
[-wK|--debug-dump=follow-links]
[-wN|--debug-dump=no-follow-links]
[-wD|--debug-dump=use-debuginfod]
[-wE|--debug-dump=do-not-use-debuginfod]
[--debug-dir=dir]
[-P|--process-links]
[--dwarf-depth=n]
[--dwarf-start=n]
[--ctf=section]
[--ctf-parent=section]
[--ctf-symbols=section]
[--ctf-strings=section]
[--sframe=section]
[-I|--histogram]
[--got-contents]
[-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, she can show you the whole vibe or just the specific little corner you're obsessed with. π
elffile... are the object files to be examined. 32-bit and 64-bit ELF files are supported, as are archives containing ELF files. No cap, she handles the whole friend group. π«Ά
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. Main character energy: unbothered, independent, detailed. β¨
π OPTIONS π
The long and short forms of options, shown here as alternatives, are equivalent. Pick your fave, bestie. At least one option besides -v or -H must be given. That's the rule β don't show up empty-handed. π
-a,--allβ Equivalent to specifying--file-header,--program-headers,--sections,--symbols,--relocs,--dynamic,--notes,--got-contents,--version-info,--arch-specific,--unwind,--section-groupsand--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. Important little detail, don't skip it. π
-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"no symbols"diagnostic. Peace and quiet, finally. π-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. She's thorough like that. π-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. The double-@is not a typo, bestie. π--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. Numbers are numbers but the base is the vibe check. π’-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. She's translating the group chat so you can actually read it. π«Ά--no-demangleβ Do not demangle low-level symbol names. This is the default. Raw name energy, I guess. π--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. So like, don't come crying to the bug tracker, 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. It's giving "pay attention to me" in the best way. π₯
-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--wideoption as well, at least when displaying symbol information. Extra tea, served hot. β--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. Not every architecture is on the guest list yet, iykyk. π«Ά-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 makesreadelfdisplay the dynamic relocations rather than the static relocations. Dynamic mode activated, slay. β‘-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. She's doing a vibe check on your file and she will let you know. π¨-x<number or name>,--hex-dump=<number or name> β dumps the section you point at as raw hexadecimal bytes π§. A number means "that section, by index, in the section table"; literally any other string means "every section in the object file with this name". You can stack this flag as many times as you want on one command line to get multiple hex dumps, no cap.-R<number or name>,--relocated-dump=<number or name> β same hex-bytes energy as above, same rules: number = section by index in the section table, other string = all sections with that name in the object file. The difference is the section contents get relocated before they're displayed β¨. Also repeatable multiple times on the command line for multiple relocated dumps.-p<number or name>,--string-dump=<number or name> β shows the indicated section's contents as printable strings π. Number = that section by index in the section table, other string = all sections with that name in the object file. Repeat it multiple times on the command line for multiple string dumps.-j<number or name>,--display-sectionβ displays the indicated section's contents according to its section header type. Like, it reads the vibe of the section first: sections containing relocations get displayed as if you'd used--relocations, sections containing symbols get displayed as if you'd used--syms, and so on π . 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). Repeatable multiple times on the command line for multiple section dumps.-z,--decompressβ asks that the section(s) being dumped by thex,Rorpoptions get decompressed before they're shown π«Ά. If the section(s) aren't compressed? They're displayed as is. No drama.-c,--archive-indexβ displays the file symbol index info chillin' in the header part of binary archives ποΈ. Does exactly what thetcommand does forar, except without using the BFD library. iykyk.-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. Compressed debug sections are automatically decompressed (temporarily!) before they're displayed. If one or more of the optional letters or words follows the switch, then only those type(s) of data get dumped π¦. The letters and words mean:"a","=abbrev"β Displays the contents of the.debug_abbrevsection."A","=addr"β Displays the contents of the.debug_addrsection."c","=cu_index"β Displays the contents of the.debug_cu_indexand/or.debug_tu_indexsections."f","=frames"β Display the raw contents of a.debug_framesection."F","=frames-interp"β Display the interpreted contents of a.debug_framesection."g","=gdb_index"β Displays the contents of the.gdb_indexand/or.debug_namessections."i","=info"β 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","=links"β 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're specified by theDW_AT_GNU_dwo_nameorDW_AT_dwo_nameattributes in the.debug_infosection."K","=follow-links"β Display the contents of any selected debug sections found in linked, separate debug info file(s) π. Heads up: this can result in multiple versions of the same debug section being displayed if it exists in more than one file.
Plus, when displaying DWARF attributes, if a form is found that references the separate debug info file, then the referenced contents get displayed too.
Note β in some distributions this option is enabled by default. It can be disabled via theNdebug 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 β 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 theDEBUGINFOD_URLSenvironment variable π. This could take some time to resolve. This behaviour can be disabled via the=do-not-use-debuginfoddebug option.
"N","=no-follow-links"β Disables the following of links to separate debug info files."D","=use-debuginfod"β Enables contacting debuginfod servers if there's a need to follow debug links. This is the default behaviour π."E","=do-not-use-debuginfod"β Disables contacting debuginfod servers when there's a need to follow debug links."l","=rawline"β Displays the contents of the.debug_linesection in a raw format."L","=decodedline"β Displays the interpreted contents of the.debug_linesection."m","=macro"β Displays the contents of the.debug_macroand/or.debug_macinfosections."o","=loc"β Displays the contents of the.debug_locand/or.debug_loclistssections."O","=str-offsets"β Displays the contents of the.debug_str_offsetssection."p","=pubnames"β Displays the contents of the.debug_pubnamesand/or.debug_gnu_pubnamessections."r","=aranges"β Displays the contents of the.debug_arangessection."R","=Ranges"β Displays the contents of the.debug_rangesand/or.debug_rnglistssections."s","=str"β Displays the contents of the.debug_str,.debug_line_strand/or.debug_str_offsetssections."t","=pubtype"β Displays the contents of the.debug_pubtypesand/or.debug_gnu_pubtypessections."T","=trace_aranges"β Displays the contents of the.trace_arangessection."u","=trace_abbrev"β Displays the contents of the.trace_abbrevsection."U","=trace_info"β 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=n β limits the dump of the".debug_info"section to n children πΈ. Only useful with--debug-dump=info. The default is to print all DIEs; the special value0for n also has 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 β prints only DIEs beginning with the DIE numbered n β. Only useful with--debug-dump=info. If specified, this option suppresses printing of any header information and all DIEs before the DIE numbered n. Only siblings and children of the specified DIE get printed. You can run it together with--dwarf-depth.--debug-dir=dir β search dir when looking for separate debug info files π.-P,--process-linksβ displays the contents of non-debug sections found in separate debuginfo files that are linked to the main file π¦. 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 π . 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=member β 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's 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-parentcan be used to specify the name used for the parent.--ctf-parent-section=section β 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 π. 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 withobjcopy, which can put them in different ELF sections but not in different members of a single CTF dict.--ctf-symbols=section,--ctf-strings=section β specify the name of another section from which the CTF file can inherit strings and symbols π. By default, the".symtab"and its linked string table are used. If either of--ctf-symbolsor--ctf-stringsis specified, the other must be specified as well β they're a package deal, fr fr.--got-contentsβ displays the contents of the file's Global Offset Table (GOT) sections, if it has any π₯. For MIPS, this option is similar to--arch-specific, but it only displays the GOT related contents and it is ignored when--arch-specificis used.-I,--histogramβ display a histogram of bucket list lengths when displaying the contents of the symbol tables π.
-v,--versionβ shows you the version number ofreadelf. That's it, that's the whole vibe β¨-W,--wideβ tellsreadelfto stop wrapping output lines to fit into 80 columns. By default,readelfbreaks section header and segment listing lines for 64-bit ELF files so they squeeze into 80 columns β and honestly? cramped. This option makesreadelfprint each section header resp. each segment on a single line, which is far more readable on terminals wider than 80 columns. treat your wide terminal right, bestie π-T,--silent-truncationβ okay so normally, whenreadelfis displaying a symbol name and it has to truncate that name to fit into an 80 column display, it appends a suffix of[...]to the name. this option disables that whole behaviour, which means you get 5 more characters of the name shown π and it restores the old behaviour ofreadelf(prior to release 2.35). retro icon behavior, ngl.-H,--helpβ displays the command-line options thatreadelfunderstands. your little map πΊοΈ@fileβ reads command-line options from file. the options it reads get inserted in place of the original@fileoption. important caveat: if file does not exist, or cannot be read, then the option will be treated literally, and not removed. no silent ghosting π«Ά
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. and plot twist: the file may itself contain additional @file options β any such options will be processed recursively. it's @file-ception π
π SEE ALSO π
objdump(1)β go say hi π- and the Info entries for binutils. that's where the deep lore lives π
π COPYRIGHT π
Copyright (c) 1991-2026 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".
fr fr that's the legal bit β please don't skip it, the FSF is watching (lovingly) π
and that's the whole page, bestie!! πβ¨ this beauty is from binutils-2.47, dated 2026-08-31, and the page itself is READELF(1). go read some ELF headers, you absolute icon ππ
π¦ where this page comes from
- arch rolling: riscv64-linux-gnu-binutils 2.47-1 Β· GPL-2.0-or-later
- π girlified by deepseek-ai/DeepSeek-V4.1-Flash-1017 on : a language model's rewrite of the original, under its terms