البرنامج الخفي (المعروف أيضًا باسم عمليات الخلفية) هو برنامج Linux أو UNIX يعمل في الخلفية. تقريبا كل daemons لها أسماء تنتهي بالحرف “d". على سبيل المثال ، httpd البرنامج الخفي الذي يتعامل مع خادم Apache ، أو sshd الذي يتعامل مع اتصالات الوصول عن بُعد لـ SSH. غالبًا ما يبدأ Linux البرامج الخفية في وقت التمهيد. تُستخدم نصوص شل النصية المخزنة في الدليل /etc/init.d لبدء وإيقاف البرامج الخفية (Daemons).
وظائف نموذجية ل Daemons
.فتح منفذ الشبكة (مثل المنفذ 80) والاستجابة لطلبات الشبكة
نظام مراقبة مثل صحة القرص الصلب أو مجموعة
. RAID
قم بتشغيل المهام المجدولة مثل
. cron
قائمة daemons لأنظمة لينوكس وأنظمة يونكس الشبيهة
amd – Auto Mount Daemon
anacron – Executed delayed cron tasks at boot time
apmd – Advanced Power Management Daemon
atd – Runs jobs queued using the at tool
autofs – Supports the automounter daemon allowing mount and unmount of devices on demand
crond – The task scheduler daemon
cupsd – CUPS printer daemon
dhcpd – Dynamic Host Configuration Protocol and Internet Bootstrap Protocol Server
ftpd – FTP Server Daemon
gated – routing daemon that handles multiple routing protocols and replaces routed and egpup
httpd – Web Server Daemon
inetd – Internet Superserver Daemon
imapd – An imap server daemon
lpd – Line Printer Daemon
memcached – In-memory distributed object caching daemon
mountd – mount daemon
mysql – Database server daemon
named – A DNS server daemon
nfsd – Network File Sharing Daemon
nfslock – Used to start and stop nfs file locking services
nmbd – Network Message Block Daemon
ntpd – Network Time Protocol service daemon
postfix – A mail transport agent used as a replacement for sendmail
postgresql – Database server daemon
routed – Manages routing tables
rpcbind – Remote Procedure Call Bind Daemon
sendmail – A mail transfer agent Daemon
smbd – Samba (an SMB Server) Daemon
smtpd – Simple Mail Transfer Protocol Daemon
snmpd – Simple Network Management Protocol Daemon
squid – A web page caching proxy server daemon
sshd – Secure Shell Server Daemon
syncd – Keeps the file systems synchronized with system memory
syslogd – System logging daemon
tcpd – Service wrapper restricts access to inetd based services through hosts.allow and hosts.deny
telnetd – Telnet Server daemon
vsftpd – Very Secure FTP Daemon
webmin – Web based administration server daemon
xinetd – Enhanced Internet Superserver Daemon
xntd – Network Time Server Daemon
كيف يمكنني بدء / إيقاف / إعادة تشغيل daemons for the shell prompt
؟
تحتاج إلى استخدام أمر الخدمة على النحو التالي
service daemon-name-here start
service daemon-name-here stop
service daemon-name-here restart
في هذا المثال ، ابدأ برنامج httpd الخفي ، وأوقفه ، وأعد تشغيله:
service httpd start
service httpd stop
service httpd restart
كيف أرى قائمة بجميع running daemon؟
service –status-all
عينة من مخرجات خادم تطوير CentOS Linux:
acpid (pid 3914) is running…
anacron is stopped
atd (pid 4433) is running…
auditd (pid 3537) is running…
automount (pid 4174) is running…
Avahi daemon is not running
Avahi DNS daemon is not running
hcid (pid 3821) is running…
sdpd (pid 3827) is running…
collectl is stopped
conmand is stopped
cpuspeed is stopped
crond (pid 4386) is running…
cupsd is stopped
dc_client is stopped
dc_server is stopped
dnsmasq is stopped
dovecot is stopped
dund is stopped
gpm (pid 4372) is running…
hald (pid 4094) is running…
hidd (pid 4144) is running…
httpd is stopped
irattach is stopped
irqbalance (pid 3686) is running…
iscsid (pid 2775) is running…
iscsid (pid 2775) is running…
Kdump is not operational
krb524d is stopped
libvirtd is stopped
lighttpd is running for example.com domain.
lighttpd is running for example.net domain.
mcstransd (pid 2932) is running…
memcached (pid 39605) is running…
dbus-daemon (pid 3802) is running…
multipathd is stopped
mysqld (pid 4319) is running…
named (pid 21265) is running…
netplugd is stopped
Configured devices:
lo br0 br1 eth0 eth1
Currently active devices:
lo eth0 eth1 br0 br1
NetworkManager is stopped
rpc.mountd is stopped
nfsd is stopped
mcstransd (pid 2932) is running…
mdadm is stopped
mdmpd is stopped
memcached (pid 39605) is running…
dbus-daemon (pid 3802) is running…
multipathd is stopped
mysqld (pid 4319) is running…
named (pid 21265) is running…
rpc.mountd is stopped
nfsd is stopped
rpc.rquotad is stopped
rpc.statd is stopped
nscd is stopped
ntpd (pid 4240) is running…
pcscd (pid 3905) is running…
sendmail (pid 4354) is running…
setroubleshootd (pid 3813) is running…
smartd (pid 4491) is running…
smbd is stopped
nmbd is stopped
snmpd (pid 4191) is running…
squid (pid 13123) is running…
openssh-daemon (pid 4217) is running…
syslogd (pid 3563) is running…
klogd (pid 3566) is running…
tux is stopped
vsftpd is stopped
winbindd is stopped
wpa_supplicant is stopped
xfs (pid 4418) is running…
xinetd (pid 4229) is running…
ypbind is stopped
yum-updatesd (pid 4525) is running…
عينة من المخرجات من أنظمة سطح مكتب Ubuntu Linux الخاصة بي:
[ ? ] acpi-support
[ ? ] acpid
[ ? ] alsa-mixer-save
[ ? ] anacron
[ + ] apache2
[ + ] apparmor
[ ? ] apport
[ ? ] arpwatch
[ ? ] atd
[ ? ] aumix
[ + ] bind9
[ ? ] binfmt-support
[ + ] bluetooth
[ – ] bootlogd
[ ? ] bridge-network-interface
[ – ] brltty
[ ? ] console-setup
[ ? ] cron
[ + ] cups
[ ? ] dbus
[ ? ] dmesg
[ ? ] dns-clean
[ ? ] failsafe-x
[ – ] fancontrol
[ ? ] gdm
[ – ] grub-common
[ ? ] gssd
[ ? ] hddtemp
[ ? ] hostname
[ ? ] hwclock
[ ? ] hwclock-save
[ ? ] idmapd
[ ? ] irqbalance
[ ? ] iscsi-network-interface
[ – ] kerneloops
[ ? ] killprocs
[ ? ] libvirt-bin
[ – ] lighttpd
[ – ] lm-sensors
[ + ] memcached
[ ? ] module-init-tools
[ ? ] mysql
[ + ] net-acct
[ ? ] network-interface
[ ? ] network-interface-security
[ ? ] network-manager
[ ? ] networking
[ ? ] ondemand
[ + ] open-iscsi
[ ? ] pcmciautils
[ ? ] plymouth
[ ? ] plymouth-log
[ ? ] plymouth-splash
[ ? ] plymouth-stop
[ ? ] portmap
[ + ] postfix
[ ? ] pppd-dns
[ ? ] procps
[ + ] pulseaudio
[ ? ] qemu-kvm
[ ? ] rc.local
[ ? ] resolvconf
[ ? ] rpc_pipefs
[ – ] rsync
[ ? ] rsyslog
[ – ] saned
[ ? ] screen-cleanup
[ ? ] sendsigs
[ – ] smartmontools
[ ? ] speech-dispatcher
[ + ] ssh
[ ? ] statd
[ ? ] stop-bootlogd
[ ? ] stop-bootlogd-single
[ + ] sysstat
[ ? ] udev
[ ? ] udev-finish
[ ? ] udevmonitor
[ ? ] udevtrigger
[ ? ] ufw
[ ? ] umountfs
[ ? ] umountnfs.sh
[ ? ] umountroot
[ ? ] unattended-upgrades
[ – ] urandom
[ + ] vmware
[ + ] vnstat
[ – ] wicd
[ + ] winbind
[ ? ] wpa-ifupdown
[ – ] x11-common