ccache

compiler cache for faster recompilation

TLDR

Show cache statistics

$ ccache -s

Show verbose cache statistics including hit rates

$ ccache -sv

Clear the cache

$ ccache -C

Set maximum cache size

$ ccache -M [5G]

Show current configuration

$ ccache -p

Zero statistics counters

$ ccache -z

Run compiler through ccache

$ ccache [gcc] -c [file.c]

Set a configuration value

$ ccache -o [max_size=10G]

Show the cache directory path

$ ccache -k cache_dir

SYNOPSIS

ccache [options]ccache compiler [compileroptions_]

ccache is a compiler cache that speeds up recompilation by caching previous compilations. When the same compilation is detected, it returns the cached result instead of recompiling.Supports GCC, Clang, MSVC and similar compilers for C, C++, Objective-C, CUDA, and assembler.

PARAMETERS

-s, --show-stats

Show cache statistics summary.

-sv

Show verbose statistics including hit/miss details.

-z, --zero-stats

Zero statistics counters.

-C, --clear

Clear entire cache.

-M, --max-size size

Set maximum cache size (e.g., 5G, 500M).

-F, --max-files count

Set maximum number of files in the cache.

-p, --show-config

Show current configuration with origins.

-k, --get-config key

Get a single configuration value.

-o, --set-config key=value

Set a configuration value persistently.

-d, --directory path

Operate on specified cache directory instead of the default.

--cleanup

Clean up cache to stay within size limit.

--evict-older-than age

Remove files older than given age (e.g., 30d, 24h).

-V, --version

Show version.

CONFIGURATION

~/.config/ccache/ccache.conf

Primary configuration file controlling cache size, compression, compiler settings, and remote storage.

/etc/ccache.conf

System-wide configuration defaults.

SETUP

Symlink method:

$ ln -s /usr/bin/ccache /usr/local/bin/gcc
ln -s /usr/bin/ccache /usr/local/bin/g++

Environment variable:

$ export CC="ccache gcc"
export CXX="ccache g++"

ENVIRONMENT

CCACHE_DIR

Path to the cache directory (default: ~/.cache/ccache or ~/.ccache).

CCACHE_CONFIGPATH

Path to the configuration file.

CCACHE_MAXSIZE

Maximum cache size (overrides config file).

CCACHE_DISABLE / CCACHE_NODISABLE

Disable or re-enable ccache.

REMOTE CACHING

Supports remote caching via HTTP, Redis, or NFS for sharing across build machines.

CAVEATS

Only caches single-file compilations. Multi-file compilation and linking fall back to the real compiler. Produces identical output to direct compilation. Precompiled headers require special configuration.