Linux getent 命令手册
作者：互联网
简介
Linux getent命令用来查看系统的数据库中的相关记录。
即使这些数据库不是在本地，比如ldap或者nis中的数据库， 也可以使用getent察看。长选项的强制或可选参数对对应的短选项也是强制或可选的。
一般语法
getent database [key ...]
getent会在上面数据库中产找key对应的value
[root@my-test-host ~]# getent --help
用法： getent [选项...] 数据库 [键 ...]
Get entries from administrative database.
-i, --no-idn disable IDN encoding
-s, --service=CONFIG 要使用的服务配置
-?, --help 给出该系统求助列表
--usage 给出简要的用法信息
-V, --version 打印程序版本号
长选项的强制或可选参数对对应的短选项也是强制或可选的。
支持的数据库：
ahosts ahostsv4 ahostsv6 aliases ethers group gshadow hosts initgroups
netgroup networks passwd protocols rpc services shadow
For bug reporting instructions, please see:
<http://www.gnu.org/software/libc/bugs.html>.
[root@my-test-host ~]# getent --usage
用法： getent [-i?V] [-s CONFIG] [--no-idn] [--service=CONFIG] [--help]
[--usage] [--version] 数据库 [键 ...]
参考实例
从hosts库中得到my-test-host的IP信息：
[root@my-test-host ~]# getent hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
127.0.0.1 localhost localhost.localdomain localhost6 localhost6.localdomain6
10.200.62.14 my-test-host
[root@my-test-host ~]# getent hosts ito
[root@my-test-host ~]# getent hosts my-test-host
10.100.10.10 my-test-host
从passwd库中得到账号zabbix信息：
[root@my-test-host ~]# getent passwd zabbix
zabbix:x:1001:1001::/home/zabbix:/bin/bash
从services中获取22、10050端口信息：
[root@my-test-host ~]# getent services 22
ssh 22/tcp
[root@my-test-host ~]# getent services 10050
zabbix-agent 10050/tcp
普通用户netstat -tlnp无法看到非自己的进程名，这时getent命令非常有用
man page
GETENT(1) User Commands GETENT(1)
NAME
getent - get entries from Name Service Switch libraries
SYNOPSIS
getent database [key ...]
DESCRIPTION
The getent command displays entries from databases supported by the Name Service
Switch libraries, which are configured in /etc/nsswitch.conf. If one or more key
arguments are provided, then only the entries that match the supplied keys will
be displayed. Otherwise, if no key is provided, all entries will be displayed
(unless the database does not support enumeration).
The database may be any of those supported by the GNU C Library, listed below:
ahosts When no key is provided, use sethostent(3), gethostent(3), and end‐
hostent(3) to enumerate the hosts database. This is identical to
using hosts. When one or more key arguments are provided, pass each
key in succession to getaddrinfo(3) with the address family
AF_UNSPEC, enumerating each socket address structure returned.
ahostsv4 Same as ahosts, but use the address family AF_INET.
ahostsv6 Same as ahosts, but use the address family AF_INET6. The call to
getaddrinfo(3) in this case includes the AI_V4MAPPED flag.
aliases When no key is provided, use setaliasent(3), getaliasent(3), and
endaliasent(3) to enumerate the aliases database. When one or more
key arguments are provided, pass each key in succession to getalias‐
byname(3) and display the result.
ethers When one or more key arguments are provided, pass each key in suc‐
cession to ether_aton(3) and ether_hostton(3) until a result is
obtained, and display the result. Enumeration is not supported on
ethers, so a key must be provided.
group When no key is provided, use setgrent(3), getgrent(3), and end‐
grent(3) to enumerate the group database. When one or more key
arguments are provided, pass each numeric key to getgrgid(3) and
each nonnumeric key to getgrnam(3) and display the result.
gshadow When no key is provided, use setsgent(3), getsgent(3), and ends‐
gent(3) to enumerate the gshadow database. When one or more key
arguments are provided, pass each key in succession to getsgnam(3)
and display the result.
hosts When no key is provided, use sethostent(3), gethostent(3), and end‐
hostent(3) to enumerate the hosts database. When one or more key
arguments are provided, pass each key to gethostbyaddr(3) or geth‐
ostbyname2(3), depending on whether a call to inet_pton(3) indicates
that the key is an IPv6 or IPv4 address or not, and display the
result.
initgroups
When one or more key arguments are provided, pass each key in suc‐
cession to getgrouplist(3) and display the result. Enumeration is
not supported on initgroups, so a key must be provided.
netgroup When one key is provided, pass the key to setnetgrent(3) and, using
getnetgrent(3) display the resulting string triple (hostname, user‐
name, domainname). Alternatively, three keys may be provided, which
are interpreted as the hostname, username and domainname to match to
a netgroup name via innetgr(3). Enumeration is not supported on
netgroup, so either one or three keys must be provided.
networks When no key is provided, use setnetent(3), getnetent(3), and endne‐
tent(3) to enumerate the networks database. When one or more key
arguments are provided, pass each numeric key to getnetbyaddr(3) and
each nonnumeric key to getnetbyname(3) and display the result.
passwd When no key is provided, use setpwent(3), getpwent(3), and endp‐
went(3) to enumerate the passwd database. When one or more key
arguments are provided, pass each numeric key to getpwuid(3) and
each nonnumeric key to getpwnam(3) and display the result.
protocols When no key is provided, use setprotoent(3), getprotoent(3), and
endprotoent(3) to enumerate the protocols database. When one or
more key arguments are provided, pass each numeric key to getproto‐
bynumber(3) and each nonnumeric key to getprotobyname(3) and display
the result.
rpc When no key is provided, use setrpcent(3), getrpcent(3), and endrp‐
cent(3) to enumerate the rpc database. When one or more key argu‐
ments are provided, pass each numeric key to getrpcbynumber(3) and
each nonnumeric key to getrpcbyname(3) and display the result.
services When no key is provided, use setservent(3), getservent(3), and end‐
servent(3) to enumerate the services database. When one or more key
arguments are provided, pass each numeric key to getservbynumber(3)
and each nonnumeric key to getservbyname(3) and display the result.
shadow When no key is provided, use setspent(3), getspent(3), and end‐
spent(3) to enumerate the shadow database. When one or more key
arguments are provided, pass each key in succession to getspnam(3)
and display the result.
EXIT STATUS
One of the following exit values can be returned by getent:
0 Command completed successfully.
1 Missing arguments, or database unknown.
2 One or more supplied key could not be found in the database.
3 Enumeration not supported on this database.
SEE ALSO
nsswitch.conf(5)
COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description
of the project, and information about reporting bugs, can be found at
http://www.kernel.org/doc/man-pages/.
Linux 2013-03-15 GETENT(1)
标签：provided,database,each,When,getent,手册,key,Linux 来源： https://www.cnblogs.com/my-show-time/p/15896708.html