OTOOL-CLASSIC(1) General Commands Manual OTOOL-CLASSIC(1)
otool-classic - object file displaying tool
otool-classic [ option ... ] [ file ... ]
The otool-classic command displays specified parts of object files or
libraries. It is the preferred tool for inspecting Mach-O binaries,
especially for binaries that are bad, corrupted, or fuzzed. It is also
useful in situations when inspecting files with new or "bleeding-edge"
Mach-O file format changes.
For historical reasons, the LLVM-based llvm-objdump(1) tool does support
displaying Mach-O information in an "otool-compatibility" mode. For more
information on using llvm-objdump(1) in this way, see the llvm-otool(1)
command-line shim. Note that llvm-objdump(1) is incapable of displaying
information in all Mach-O files.
If the -m option is not used the file arguments may be of the form
libx.a(foo.o), to request information about only that object file and not
the entire library. (Typically this argument must be quoted,
``libx.a(foo.o)'', to get it past the shell.) Otool-classic understands
both Mach-O (Mach object) files and universal file formats.
Otool-classic can display the specified information in either its raw
(numeric) form (without the -v flag), or in a symbolic form using macro
names of constants, etc. (with the -v or -V flag).
At least one of the following options must be specified:
-a Display the archive header, if the file is an archive.
-S Display the contents of the `__.SYMDEF' file, if the file is an
-f Display the universal headers.
-h Display the Mach header.
-l Display the load commands.
-L Display the names and version numbers of the shared libraries that
the object file uses, as well as the shared library ID if the file
is a shared library.
-D Display just the install name of a shared library. See
install_name_tool(1) for more info.
-s segname sectname
Display the contents of the section (segname,sectname). If the -v
flag is specified, the section is displayed as its type, unless
the type is zero (the section header flags). Also the sections
(__OBJC,__protocol), (__OBJC,__string_object) and
(__OBJC,__runtime_setup) are displayed symbolically if the -v flag
is specified. For unknown section types, if the -V flag is
specified, the contents of the section are displayed in a
canonical hex+ASCII display, where a column of hexadecimal values
print along side a column of ASCII characters.
-t Display the contents of the (__TEXT,__text) section. With the -v
flag, this disassembles the text. With the -V flag, it also
symbolically disassembles the operands.
-x Display the contents of every __text section found in the file.
This is useful when looking at the Mach kernel and other files
with __text sections in more than one segment, or where the __text
section is somewhere other than __TEXT. When used with the -v
flag, this disassembles the text. When used with the -V flag, it
also symbolically disassembles the operands.
-d Display the contents of the (__DATA,__data) section.
-o Display the contents of the __OBJC segment used by the Objective-C
-r Display the relocation entries.
-c Display the argument strings (argv and envp) from a core file.
-I Display the indirect symbol table.
-T Display the table of contents for a dynamically linked shared
-R Display the reference table of a dynamically linked shared
-M Display the module table of a dynamically linked shared library.
-H Display the two-level namespace hints table.
-G Display the data in code table.
-C Display the linker optimization hints (-v for verbose mode can
also be added).
-P Print the info plist section, (__TEXT,__info_plist), as strings.
Print bind and rebase information used by dyld to resolve external
references in a final linked binary.
Print raw dyld bind and rebase opcodes present in a final linked
binary. These opcodes are stored in a region pointed to by
LC_DYLD_INFO* load commands.
When doing disassembly print latency annotations for instructions.
Print raw chained fixup data present in a final linked binary
built with chained fixups. The chained fixup data are stored
either in a region pointed to by the LC_DYLD_CHAINED_FIXUPS load
command or in a (__TEXT,__chain_starts) section. This data
includes the fixup chain's starting location on each page by
segment and symbol information for each bind. Use the -dyld_info
option to see the individual links in each chain.
The following options may also be given:
-j When doing disassembly print the opcode bytes of the instructions.
-m The object file names are not assumed to be in the archive(member)
syntax, which allows file names containing parenthesis.
Used with the -t and -v or -V options to start the disassembly
from symbol name and continue to the end of the (__TEXT,__text)
section. This option can also be used with the -x option to begin
disassembly from symbol name in any segment where a __text section
-q Use the llvm disassembler when doing disassembly; this is
available for the x86 and arm architectures. This is the default.
-Q Use otool-classic(1)'s disassembler when doing disassembly.
-v Display verbosely (symbolically) when possible.
-V Display the disassembled operands symbolically (this implies the
-v option). This is useful with the -s, -t, and -x options.
-X Don't print leading addresses or headers with disassembly of
When disassembling a binary using the -s, -t, or -o options, add
an arbitrary slide to each pointer value when it is displayed.
This is useful for matching otool output with that from a running
Specifies the architecture, arch_type, of the file for
otool-classic(1) to operate on when the file is a universal file
(aka a file with multiple architectures). (See arch(3) for the
currently known arch_types.) The arch_type can be "all" to
operate on all architectures in the file. The default is to
display only the host architecture, if the file contains it;
otherwise, all architectures in the file are shown.
When doing disassembly print the decimal offset from the last
When doing disassembly using the llvm disassembler use the cpu
Print the otool-classic(1) version information.
dyld(1), install_name_tool(1), libtool(1), lipo(1), llvm-otool(1), and
Apple Inc. July 31, 2020 OTOOL-CLASSIC(1)