Cosmopolitan Libc makes C a build-once run-anywhere language, like Java, except it doesn't need an interpreter or virtual machine. Instead, it reconfigures stock GCC and Clang to output a POSIX-approved polyglot format that runs natively on Linux + Mac + Windows + FreeBSD + OpenBSD + NetBSD + BIOS with the best possible performance and the tiniest footprint imaginable.
For an introduction to this project, please read the actually portable executable blog post and cosmopolitan libc website. We also have API documentation.
You can start by obtaining a release of our cosmocc compiler from
https://cosmo.zip/pub/cosmocc/.
mkdir -p cosmocc
cd cosmocc
wget https://cosmo.zip/pub/cosmocc/cosmocc.zip
unzip cosmocc.zipHere's an example program we can write:
// hello.c
#include <stdio.h>
int main() {
printf("hello world\n");
}It can be compiled as follows:
cosmocc -o hello hello.c
./helloThe Cosmopolitan Libc runtime links some heavyweight troubleshooting features by default, which are very useful for developers and admins. Here's how you can log system calls:
./hello --straceHere's how you can get a much more verbose log of function calls:
./hello --ftraceYou can use the Cosmopolitan's toolchain to build conventional open source projects which use autotools. This strategy normally works:
export CC=x86_64-unknown-cosmo-cc
export CXX=x86_64-unknown-cosmo-c++
./configure --prefix=/opt/cosmos/x86_64
make -j
make installCosmopolitan can be compiled from source on any of our supported platforms. The Makefile will download cosmocc automatically.
It's recommended that you install a systemwide APE Loader. This command
requires sudo access to copy the ape command to a system folder and
register with binfmt_misc on Linux, for even more performance.
ape/apeinstall.shYou can now build the mono repo with any modern version of GNU Make. To make life easier, we've included one in the cosmocc toolchain, which is guaranteed to be compatible and furthermore includes our extensions for doing build system sandboxing.
build/bootstrap/make -j8
o//examples/helloSince the Cosmopolitan repository is very large, you might only want to build one particular thing. Here's an example of a target that can be compiled relatively quickly, which is a simple POSIX test that only depends on core LIBC packages.
rm -rf o//libc o//test
build/bootstrap/make o//test/posix/signal_test
o//test/posix/signal_testSometimes it's desirable to build a subset of targets, without having to
list out each individual one. For example if you wanted to build and run
all the unit tests in the TEST_POSIX package, you could say:
build/bootstrap/make o//test/posixCosmopolitan provides a variety of build modes. For example, if you want really tiny binaries (as small as 12kb in size) then you'd say:
build/bootstrap/make m=tinyYou can furthermore cut out the bloat of other operating systems, and have Cosmopolitan become much more similar to Musl Libc.
build/bootstrap/make m=tinylinuxFor further details, see //build/config.mk.
To print a log of system calls to stderr:
cosmocc -o hello hello.c
./hello --straceTo print a log of function calls to stderr:
cosmocc -o hello hello.c
./hello --ftraceBoth strace and ftrace use the unbreakable kprintf() facility, which is able to be sent to a file by setting an environment variable.
export KPRINTF_LOG=log
./hello --straceHere's the recommended ~/.gdbinit config:
set host-charset UTF-8
set target-charset UTF-8
set target-wide-charset UTF-8
set osabi none
set complaints 0
set confirm off
set history save on
set history filename ~/.gdb_history
define asm
layout asm
layout reg
end
define src
layout src
layout reg
end
srcYou normally run the .dbg file under gdb. If you need to debug the
`` file itself, then you can load the debug symbols independently as
gdb foo -ex 'add-symbol-file foo.dbg 0x401000'If you use zsh and have trouble running APE programs try sh -c ./prog
or simply upgrade to zsh 5.9+ (since we patched it two years ago). The
same is the case for Python subprocess, old versions of fish, etc.
Some Linux systems are configured to launch MZ executables under WINE. Other distros configure their stock installs so that APE programs will print "run-detectors: unable to find an interpreter". For example:
jart@ubuntu:~$ wget https://cosmo.zip/pub/cosmos/bin/dash
jart@ubuntu:~$ chmod +x dash
jart@ubuntu:~$ ./dash
run-detectors: unable to find an interpreter for ./dashYou can fix that by registering APE with binfmt_misc:
sudo wget -O /usr/bin/ape https://cosmo.zip/pub/cosmos/bin/ape-$(uname -m).elf
sudo chmod +x /usr/bin/ape
sudo sh -c "echo ':APE:M::MZqFpD::/usr/bin/ape:' >/proc/sys/fs/binfmt_misc/register"
sudo sh -c "echo ':APE-jart:M::jartsr::/usr/bin/ape:' >/proc/sys/fs/binfmt_misc/register"You should be good now. APE will not only work, it'll launch executables
400µs faster now too. However if things still didn't work out, it's also
possible to disable binfmt_misc as follows:
sudo sh -c 'echo -1 > /proc/sys/fs/binfmt_misc/cli' # remove Ubuntu's MZ interpreter
sudo sh -c 'echo -1 > /proc/sys/fs/binfmt_misc/status' # remove ALL binfmt_misc entriesIt's normally unsafe to use APE in a WSL environment, because it tries to run MZ executables as WIN32 binaries within the WSL environment. In order to make it safe to use Cosmopolitan software on WSL, run this:
sudo sh -c "echo -1 > /proc/sys/fs/binfmt_misc/WSLInterop"The Cosmopolitan development team collaborates on the Redbean Discord server. You're welcome to join us! https://discord.gg/FwAVVu7eJ4
| Platform | Min Version | Circa |
|---|---|---|
| AMD | K8 Venus | 2005 |
| Intel | Core | 2006 |
| Linux | 2.6.18 | 2007 |
| Windows | 8 [1] | 2012 |
| Darwin (macOS) | 23.1.0+ | 2023 |
| OpenBSD | 7 | 2021 |
| FreeBSD | 13 | 2020 |
| NetBSD | 9.2 | 2021 |
[1] See our vista branch for a community supported version of Cosmopolitan that works on Windows Vista and Windows 7.
Funding for this project is crowdsourced using GitHub Sponsors and Patreon. Your support is what makes this project possible. Thank you! We'd also like to give special thanks to the following groups and individuals:
For publicly sponsoring our work at the highest tier.
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