什么是服务

什么是程序（Computer Program）？
全称计算机程序或电脑程式，简称程序，是一组计算机能识别和执行的指令
什么是进程（Process）？
计算机程序关于某数据集合上的一次运行活动
什么是服务？
特定的进程
什么是自有服务？
Linux系统开机后自动运行的服务
例如：SSH服务

管理服务的命令：systemctl

列出服务

列出所有服务（含启动和冇启动的）

systemctl list-units --type service --all

列出所有启动的服务

systemctl list-units --type service

列出指定服务

systemctl list-units --type service mysqld.service

UNIT	LOAD	ACTIVE	SUB	DESCRIPTION
mysqld.service	loaded	active	running	MySQL Server

列	原文	译文
LOAD	Reflects whether the unit definition was properly loaded	单元是否被正确加载
ACTIVE	The high-level unit activation state, i.e. generalization of SUB	高级单元活跃状态
SUB	The low-level unit activation state, values depend on unit type	低级单元活跃状态

显示所有已安装的单元文件

systemctl list-unit-files

服务启停

systemctl 选项 服务名

选项	说明
start	启动
stop	停止
restart	重启

开机自动启动服务

允许指定服务开机自启

systemctl enable 服务名

禁用指定服务开机自启

systemctl disable 服务名

服务状态

systemctl status 服务名

例如：systemctl status mysqld

● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since Wed 2022-11-16 19:55:58 CST; 21h ago
  Process: 9065 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 8991 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 9069 (mysqld)
   CGroup: /system.slice/mysqld.service
           └─9069 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

软件包

软件安装包，有：源码包和二进制包
源码包：因为计算机只识别机器语言，所以要将源码编译为机器语言才能安装
二进制包：源码包经过成功编译之后产生的包，可直接安装

RPM

全称：RedHat Package Manager
作用
对Linux软件包进行管理，包括：查询、卸载、安装、更新
RPM依赖：如果软件A 依赖软件B，就要先装B再装A 才能使A可运行

# 查询
rpm {-q|--query} [select-options] [query-options]
# 安装
rpm {-i|--install} [install-options] PACKAGE_FILE ...
# 升级
rpm {-U|--upgrade} [install-options] PACKAGE_FILE ...
# 删除
rpm {-e|--erase} [--allmatches] [--justdb] [--nodeps] [--noscripts] [--notriggers] [--test] PACKAGE_NAME ...

查询安装了什么软件

查询全部软件

rpm -qa

查询指定名称的软件

rpm -qa | grep 软件名称

-a或--all：Query all installed packages.

卸载某个软件

rpm -e 软件的完整名称

安装某个软件

rpm -ivh 软件包名称

参数	说明
`-v`	打印详细信息
`-h`或`hash`	显示安装进度（要配合`-v`使用）

查询文件所属的包名

rpm -qf 被查询的文件

例如：rpm -qf /var/lib/mysql

查询软件安装后，生成了哪些文件

rpm -ql 软件名称

例如：rpm -ql mysql-community-server-5.7.16-1.el7.x86_64

/etc/logrotate.d/mysql
/etc/my.cnf
/etc/my.cnf.d
/usr/bin/innochecksum
/usr/bin/lz4_decompress
/usr/bin/my_print_defaults
/usr/bin/myisam_ftdump
/usr/bin/myisamchk
/usr/bin/myisamlog
/usr/bin/myisampack
/usr/bin/mysql_install_db
/usr/bin/mysql_plugin
/usr/bin/mysql_secure_installation
/usr/bin/mysql_ssl_rsa_setup
/usr/bin/mysql_tzinfo_to_sql
/usr/bin/mysql_upgrade
/usr/bin/mysqld_pre_systemd
/usr/bin/mysqldumpslow
/usr/bin/perror
/usr/bin/replace
/usr/bin/resolve_stack_dump
/usr/bin/resolveip
/usr/bin/zlib_decompress
/usr/lib/systemd/system/mysqld.service
/usr/lib/systemd/system/mysqld@.service
/usr/lib/tmpfiles.d/mysql.conf
/usr/lib64/mysql/mecab
/usr/lib64/mysql/mecab/dic
/usr/lib64/mysql/mecab/dic/ipadic_euc-jp
/usr/lib64/mysql/mecab/dic/ipadic_euc-jp/char.bin
/usr/lib64/mysql/mecab/dic/ipadic_euc-jp/dicrc
/usr/lib64/mysql/mecab/dic/ipadic_euc-jp/left-id.def
/usr/lib64/mysql/mecab/dic/ipadic_euc-jp/matrix.bin
/usr/lib64/mysql/mecab/dic/ipadic_euc-jp/pos-id.def
/usr/lib64/mysql/mecab/dic/ipadic_euc-jp/rewrite.def
/usr/lib64/mysql/mecab/dic/ipadic_euc-jp/right-id.def
/usr/lib64/mysql/mecab/dic/ipadic_euc-jp/sys.dic
/usr/lib64/mysql/mecab/dic/ipadic_euc-jp/unk.dic
/usr/lib64/mysql/mecab/dic/ipadic_sjis
/usr/lib64/mysql/mecab/dic/ipadic_sjis/char.bin
/usr/lib64/mysql/mecab/dic/ipadic_sjis/dicrc
/usr/lib64/mysql/mecab/dic/ipadic_sjis/left-id.def
/usr/lib64/mysql/mecab/dic/ipadic_sjis/matrix.bin
/usr/lib64/mysql/mecab/dic/ipadic_sjis/pos-id.def
/usr/lib64/mysql/mecab/dic/ipadic_sjis/rewrite.def
/usr/lib64/mysql/mecab/dic/ipadic_sjis/right-id.def
/usr/lib64/mysql/mecab/dic/ipadic_sjis/sys.dic
/usr/lib64/mysql/mecab/dic/ipadic_sjis/unk.dic
/usr/lib64/mysql/mecab/dic/ipadic_utf-8
/usr/lib64/mysql/mecab/dic/ipadic_utf-8/char.bin
/usr/lib64/mysql/mecab/dic/ipadic_utf-8/dicrc
/usr/lib64/mysql/mecab/dic/ipadic_utf-8/left-id.def
/usr/lib64/mysql/mecab/dic/ipadic_utf-8/matrix.bin
/usr/lib64/mysql/mecab/dic/ipadic_utf-8/pos-id.def
/usr/lib64/mysql/mecab/dic/ipadic_utf-8/rewrite.def
/usr/lib64/mysql/mecab/dic/ipadic_utf-8/right-id.def
/usr/lib64/mysql/mecab/dic/ipadic_utf-8/sys.dic
/usr/lib64/mysql/mecab/dic/ipadic_utf-8/unk.dic
/usr/lib64/mysql/mecab/etc
/usr/lib64/mysql/mecab/etc/mecabrc
/usr/lib64/mysql/plugin
/usr/lib64/mysql/plugin/adt_null.so
/usr/lib64/mysql/plugin/auth_socket.so
/usr/lib64/mysql/plugin/debug
/usr/lib64/mysql/plugin/debug/adt_null.so
/usr/lib64/mysql/plugin/debug/auth_socket.so
/usr/lib64/mysql/plugin/debug/ha_example.so
/usr/lib64/mysql/plugin/debug/innodb_engine.so
/usr/lib64/mysql/plugin/debug/keyring_file.so
/usr/lib64/mysql/plugin/debug/keyring_udf.so
/usr/lib64/mysql/plugin/debug/libmemcached.so
/usr/lib64/mysql/plugin/debug/libpluginmecab.so
/usr/lib64/mysql/plugin/debug/locking_service.so
/usr/lib64/mysql/plugin/debug/mypluglib.so
/usr/lib64/mysql/plugin/debug/mysql_no_login.so
/usr/lib64/mysql/plugin/debug/mysqlx.so
/usr/lib64/mysql/plugin/debug/rewrite_example.so
/usr/lib64/mysql/plugin/debug/rewriter.so
/usr/lib64/mysql/plugin/debug/semisync_master.so
/usr/lib64/mysql/plugin/debug/semisync_slave.so
/usr/lib64/mysql/plugin/debug/validate_password.so
/usr/lib64/mysql/plugin/debug/version_token.so
/usr/lib64/mysql/plugin/ha_example.so
/usr/lib64/mysql/plugin/innodb_engine.so
/usr/lib64/mysql/plugin/keyring_file.so
/usr/lib64/mysql/plugin/keyring_udf.so
/usr/lib64/mysql/plugin/libmemcached.so
/usr/lib64/mysql/plugin/libpluginmecab.so
/usr/lib64/mysql/plugin/locking_service.so
/usr/lib64/mysql/plugin/mypluglib.so
/usr/lib64/mysql/plugin/mysql_no_login.so
/usr/lib64/mysql/plugin/mysqlx.so
/usr/lib64/mysql/plugin/rewrite_example.so
/usr/lib64/mysql/plugin/rewriter.so
/usr/lib64/mysql/plugin/semisync_master.so
/usr/lib64/mysql/plugin/semisync_slave.so
/usr/lib64/mysql/plugin/validate_password.so
/usr/lib64/mysql/plugin/version_token.so
/usr/sbin/mysqld
/usr/sbin/mysqld-debug
/usr/share/doc/mysql-community-server-5.7.16
/usr/share/doc/mysql-community-server-5.7.16/COPYING
/usr/share/doc/mysql-community-server-5.7.16/ChangeLog
/usr/share/doc/mysql-community-server-5.7.16/INFO_BIN
/usr/share/doc/mysql-community-server-5.7.16/INFO_SRC
/usr/share/doc/mysql-community-server-5.7.16/README
/usr/share/doc/mysql-community-server-5.7.16/my-default.cnf
/usr/share/man/man1/innochecksum.1.gz
/usr/share/man/man1/lz4_decompress.1.gz
/usr/share/man/man1/my_print_defaults.1.gz
/usr/share/man/man1/myisam_ftdump.1.gz
/usr/share/man/man1/myisamchk.1.gz
/usr/share/man/man1/myisamlog.1.gz
/usr/share/man/man1/myisampack.1.gz
/usr/share/man/man1/mysql.server.1.gz
/usr/share/man/man1/mysql_install_db.1.gz
/usr/share/man/man1/mysql_plugin.1.gz
/usr/share/man/man1/mysql_secure_installation.1.gz
/usr/share/man/man1/mysql_ssl_rsa_setup.1.gz
/usr/share/man/man1/mysql_tzinfo_to_sql.1.gz
/usr/share/man/man1/mysql_upgrade.1.gz
/usr/share/man/man1/mysqldumpslow.1.gz
/usr/share/man/man1/mysqlman.1.gz
/usr/share/man/man1/perror.1.gz
/usr/share/man/man1/replace.1.gz
/usr/share/man/man1/resolve_stack_dump.1.gz
/usr/share/man/man1/resolveip.1.gz
/usr/share/man/man1/zlib_decompress.1.gz
/usr/share/man/man8/mysqld.8.gz
/usr/share/mysql/dictionary.txt
/usr/share/mysql/fill_help_tables.sql
/usr/share/mysql/innodb_memcached_config.sql
/usr/share/mysql/install_rewriter.sql
/usr/share/mysql/magic
/usr/share/mysql/my-default.cnf
/usr/share/mysql/mysql-log-rotate
/usr/share/mysql/mysql_security_commands.sql
/usr/share/mysql/mysql_sys_schema.sql
/usr/share/mysql/mysql_system_tables.sql
/usr/share/mysql/mysql_system_tables_data.sql
/usr/share/mysql/mysql_test_data_timezone.sql
/usr/share/mysql/uninstall_rewriter.sql
/var/lib/mysql
/var/lib/mysql-files
/var/lib/mysql-keyring
/var/run/mysqld