STRIP(1)

📦 version 12.2.0, in nixpkgs unstable

💅 STRIP(1) — GNU Development Tools

okay so bestie, you found strip(1). she's a GNU Development Tools girlie and she has one job: yeeting symbols out of object files. let's get into it 🎀

✨ NAME ✨

strip — Discard symbols from object files.

🌸 SYNOPSIS 🌸

strip [-F bfdname |--target=bfdname]
      [-I bfdname |--input-target=bfdname]
      [-O bfdname |--output-target=bfdname]
      [-s|--strip-all]
      [-S|-g|-d|--strip-debug]
      [--strip-dwo]
      [-K symbolname|--keep-symbol=symbolname]
      [-M|--merge-notes][--no-merge-notes]
      [-N symbolname |--strip-symbol=symbolname]
      [-w|--wildcard]
      [-x|--discard-all] [-X |--discard-locals]
      [-R sectionname |--remove-section=sectionname]
      [--remove-relocations=sectionpattern]
      [-o file] [-p|--preserve-dates]
      [-D|--enable-deterministic-archives]
      [-U|--disable-deterministic-archives]
      [--keep-file-symbols]
      [--only-keep-debug]
      [-v |--verbose] [-V|--version]
      [--help] [--info]
      objfile...

🦋 DESCRIPTION 🦋

GNU strip discards, like, all the symbols from object files objfile. the list of object files can include archives too, no cap. but bestie — at least one object file must be given. you can't just run her into the void 💀

key thing, and this is the main character detail: strip modifies the files named in its argument, rather than writing modified copies under different names. she's an in-place queen, she does not do "save as". 🙈

💅 OPTIONS 💅

  • -F bfdname, --target=bfdname — treat the original objfile as a file with the object code format bfdname, and rewrite it in that same format. glow-up in place ✨
  • --help — show a summary of the options to strip and dip. so valid.
  • --info — display a list showing all architectures and object formats available. the whole menu, basically 🍓
  • -I bfdname, --input-target=bfdname — treat the original objfile as a file with the object code format bfdname. i.e. "she's giving bfdname on the way in."
  • -O bfdname, --output-target=bfdname — replace objfile with a file in the output format bfdname. "she's giving bfdname on the way out."
  • -R sectionname, --remove-section=sectionname — remove any section named sectionname from the output file, on top of whatever sections would otherwise be removed. this option may be given more than once.
⚠️ note that using this option inappropriately may make the output file unusable. she's powerful, bestie, respect the power 😭

the wildcard character * may be given at the end of sectionname. if so, then any section starting with sectionname will be removed.

and if the first character of sectionpattern is the exclamation point (!) then matching sections will not be removed, even if an earlier use of --remove-section on the same command line would otherwise remove it. for example:

          --remove-section=.text.* --remove-section=!.text.foo

will remove all sections matching the pattern .text.*, but will not remove the section .text.foo. the ! is literally the "not this one bestie" flag 🫶

  • --remove-relocations=sectionpattern — remove relocations from the output file for any section matching sectionpattern. this option may be given more than once.
⚠️ again, note that using this option inappropriately may make the output file unusable. same warning, same energy.

wildcard characters are accepted in sectionpattern. for example:

          --remove-relocations=.text.*

will remove the relocations for all sections matching the patter .text.*.

if the first character of sectionpattern is the exclamation point (!) then matching sections will not have their relocation removed, even if an earlier use of --remove-relocations on the same command line would otherwise cause the relocations to be removed. for example:

          --remove-relocations=.text.* --remove-relocations=!.text.foo

will remove all relocations for sections matching the pattern .text.*, but will not remove relocations for the section .text.foo.

  • -s, --strip-all — remove all symbols. all of them. every last one. she ate and left no crumbs 💀
  • -g, -S, -d, --strip-debug — remove debugging symbols only. a gentle, targeted cleanse 🧚
  • --strip-dwo — remove the contents of all DWARF .dwo sections, leaving the remaining debugging sections and all symbols intact. see the description of this option in the objcopy section for more information. (go read her sister's page, iykyk)
  • --strip-unneeded — remove all symbols that are not needed for relocation processing.
  • -K symbolname, --keep-symbol=symbolname — when stripping symbols, keep symbol symbolname even if it would normally be stripped. this option may be given more than once. the VIP list 💖
  • -M, --merge-notes, --no-merge-notes — for ELF files, attempt (or do not attempt) to reduce the size of any SHT_NOTE type sections by removing duplicate notes. the default is to attempt this reduction. so she's optimising by default, iconic.
  • -N symbolname, --strip-symbol=symbolname — remove symbol symbolname from the source file. this option may be given more than once, and may be combined with strip options other than -K. yes, keep-list and kill-list, pick your fighter ⚔️
  • -o file — put the stripped output in file, rather than replacing the existing file. when this argument is used, only one objfile argument may be specified. one in, one out, no group project 🌈
  • -p, --preserve-dates — preserve the access and modification dates of the file. her timestamps stay flawless 💅
  • -D, --enable-deterministic-archives — operate in deterministic mode. when copying archive members and writing the archive index, use zero for UIDs, GIDs, timestamps, and use consistent file modes for all files.

if binutils was configured with --enable-deterministic-archives, then this mode is on by default. it can be disabled with the -U option, below.

  • -U, --disable-deterministic-archives — do not operate in deterministic mode. this is the inverse of the -D option, above: when copying archive members and writing the archive index, use their actual UID, GID, timestamp, and file mode values.

this is the default unless binutils was configured with --enable-deterministic-archives.

  • -w, --wildcard — permit regular expressions in symbolnames used in other command line options. the question mark (?), asterisk (*), backslash (\) and square brackets ([]) operators can be used anywhere in the symbol name. if the first character of the symbol name is the exclamation point (!) then the sense of the switch is reversed for that symbol. for example:
          -w -K !foo -K fo*

would cause strip to only keep symbols that start with the letters "fo", but to discard the symbol "foo". the ! really said "not you though" 😭

  • -x, --discard-all — remove non-global symbols.
  • -X, --discard-locals — remove compiler-generated local symbols. (these usually start with L or ..)
  • --keep-file-symbols — when stripping a file, perhaps with --strip-debug or --strip-unneeded, retain any symbols specifying source file names, which would otherwise get stripped. protect the source file names at all costs 🫶
  • --only-keep-debug — strip a file, emptying the contents of any sections that would not be stripped by --strip-debug and leaving the debugging sections intact. in ELF files, this preserves all the note sections in the output as well.

note — the section headers of the stripped sections are preserved, including their sizes, but the contents of the section are discarded. the section headers are preserved so that other tools can match up the debuginfo file with the real executable, even if that executable has been relocated to a different address space. the headers are literally the receipts 🧾

the intention is that this option will be used in conjunction with --add-gnu-debuglink to create a two part executable. one a stripped binary which will occupy less space in RAM and in a distribution and the second a debugging information file which is only needed if debugging abilities are required. the suggested procedure to create these files is as follows:

  1. Link the executable as normal. Assuming that is is called "foo" then...
  2. Run objcopy --only-keep-debug foo foo.dbg to create a file containing the debugging info.
  3. Run objcopy --strip-debug foo to create a stripped executable.
  4. Run objcopy --add-gnu-debuglink=foo.dbg foo to add a link to the debugging info into the stripped executable.

note — the choice of .dbg as an extension for the debug info file is arbitrary. also the --only-keep-debug step is optional. you could instead do this:

  1. Link the executable as normal.
  2. Copy "foo" to "foo.full"
  3. Run strip --strip-debug foo
  4. Run objcopy --add-gnu-debuglink=foo.full foo

i.e., the file pointed to by the --add-gnu-debuglink can be the full executable. it does not have to be a file created by the --only-keep-debug switch.

note — this switch is only intended for use on fully linked files. it does not make sense to use it on object files where the debugging information may be incomplete. besides the gnu_debuglink feature currently only supports the presence of one filename containing debugging information, not multiple filenames on a one-per-object-file basis.

  • -V, --version — show the version number for strip. know your icon's era 🎀
  • -v, --verbose — verbose output: list all object files modified. in the case of archives, strip -v lists all members of the archive. she's narrating her own actions, main character energy 👑
  • @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. it's files all the way down, bestie 🌀

🔥 SEE ALSO 🔥

  • the Info entries for binutils.

Copyright (c) 1991-2018 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".

and that's the whole page, bestie 🦋 this one shipped as binutils-2.30, dated 2018-01-27 — go strip something (responsibly, with -p if you care about her timestamps) 💖✨ 🎀

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