Global USE flags

Flag Description Packages
berkdb 2
bzip2 2
cdb 2
cgi Install CGI server and scripts. 5
debug 8
doc 7
examples 3
gdbm 2
ipv6 2
json Enable JSON support 2
ldap 2
lua 2
luajit 11
lz4 Enable support for compressed pcap logging using the LZ4 algorithm 2
mysql 2
nls 2
odbc 2
postgres 2
sasl 2
selinux 2
session 2
ssl Enable HTTPS module for http. Enable SSL/TLS support for POP3/IMAP/SMTP for mail. 4
static-libs 9
syslog Use syslog for error messages 2
systemd 7
test 16
threads 3

Category USE flags

app-metrics

Flag Description Packages
pie 3

sys-cluster

Flag Description Packages
fuse Install the mfsmount utility. 4

Local USE flags

app-admin

logstash-bin

Flag Description
x-pack

loki

Flag Description
fluent-bit Build the fluent-bit plugin to publish from <pkg>app-admin/fluent-bit</pkg>
promtail Build the promtail log gathering agent
server Build the loki server
tools Build the loki tools logcli and loki-canary

dev-db

omnipitr

Flag Description
gzip
lzma
xz

rethinkdb

Flag Description
jemalloc
tcmalloc

dev-lang

php

Flag Description
${IUSE}
acl
apache2
apparmor
argon2
avif
bcmath Add support for libbcmath
calendar
cjk
cli Enable CLI SAPI
coverage Include gcov symbols for test coverage and lcov reports. Only useful for extension developers, and requires GCC.
crypt
ctype Enable ctype functions
curl
embed Enable embed SAPI
enchant Add supports Enchant spelling library.
exif
ffi
fileinfo Add fileinfo extension support
filter Add filter extension support
firebird
flatfile Add dbm support for flat files
fpm Enable the FastCGI Process Manager SAPI
ftp
gd Adds support for gd (bundled with PHP)
gmp
hash Enable the hash extension
iconv
imap
inifile Add dbm support for .ini files
intl Enables the intl extension for extended internalization support
iodbc
jit
kerberos
ldap-sasl Add SASL support for the PHP LDAP extension
libedit
libressl
lmdb
mhash
mssql
mysqli
oci8-instant-client
opcache Enables built-in opcode cache, replacing pecl-apc et al.
pcntl Add support for process creation functions
pdo Enable the bundled PDO extensions
phar Enables the phar extension to provide phar archive support
phpdbg
posix
qdbm
readline
recode
session-mm
sharedmem Add support for shared memory use
simplexml Support for SimpleXML
snmp
soap
sockets
sodium
spell
sqlite
sysvipc Support for System V-compatible inter-process communication
tidy
tokenizer Add support for the PHP file parser
tokyocabinet
truetype
unicode
vpx
wddx Add support for Web Distributed Data eXchange
webp
xml
xmlreader Enable XMLReader support
xmlrpc
xmlwriter Enable XMLWriter support
xpm
xslt Enable the XSL extension
zip
zlib

dev-php

pecl-memcached

Flag Description
igbinary Enable support for the igbinary serializer

net-analyzer

ncrack

Flag Description
ssh

suricata

Flag Description
af-packet Enable AF_PACKET support
af-xdp Enable AF_XDP support
bpf Enable support for eBPF (as well as XDP if supported by the kernel and the NIC driver) for low-level, high-speed packet processing
control-socket Enable unix socket
cuda
detection Enable detection modules
geoip
hardened
hyperscan Enable high-performance regex matching with Hyperscan
ndpi
nflog Enable libnetfilter_log support
nfqueue Enable NFQUEUE support for inline IDP
pfring
redis Enable Redis support

net-libs

libsrtp

Flag Description
aesicm Use AES ICM cryptographic algorithm
console Use /dev/console instead of stdout for error messages
nss Use NSS crypto primitives
openssl Use OpenSSL crypto primitives

sofia-sip

Flag Description
glib Add support to <pkg>dev-libs/glib</pkg>-based mainloop, to allow using Sofia-SIP on glib-based programs.

net-misc

janus-gateway

Flag Description
static

net-print

samsung-unified-driver

Flag Description
cups
network Enable network printing support
scanner

sys-cluster

lizardfs

Flag Description
devel
fuse3 Use new FUSE library.

moosefs

Flag Description
gui

virtual

lua

Flag Description
bit

www-servers

nginx

Flag Description
aio Enables file AIO support
http Enable HTTP core support
http-cache Enable HTTP cache support
http2
http3
ktls
libatomic Use libatomic instead of builtin atomic operations
nginx_modules_
nginx_modules_http_
nginx_modules_http_addition
nginx_modules_http_dav
nginx_modules_http_rewrite
nginx_modules_http_spdy
nginx_modules_http_stub_status
nginx_modules_http_xslt
nginx_modules_mail_
nginx_modules_stream_
pcre
pcre-jit Enable JIT for pcre
pcre2
rtmp
vim-syntax

x11-drivers

evdi

Flag Description
python Build PyEvdi