root@PC-RENGUOQIANG:~# cat /etc/passwd root:x:0:0:root:/root:/bin/bash daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin bin:x:2:2:bin:/bin:/usr/sbin/nologin sys:x:3:3:sys:/dev:/usr/sbin/nologin sync:x:4:65534:sync:/bin:/bin/sync games:x:5:60:games:/usr/games:/usr/sbin/nologin man:x:6:12:man:/var/cache/man:/usr/sbin/nologin lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin mail:x:8:8:mail:/var/mail:/usr/sbin/nologin news:x:9:9:news:/var/spool/news:/usr/sbin/nologin uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin proxy:x:13:13:proxy:/bin:/usr/sbin/nologin www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin backup:x:34:34:backup:/var/backups:/usr/sbin/nologin list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin irc:x:39:39:ircd:/var/run/ircd:/usr/sbin/nologin gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin systemd-timesync:x:100:102:systemd Time Synchronization,,,:/run/systemd:/bin/false systemd-network:x:101:103:systemd Network Management,,,:/run/systemd/netif:/bin/false systemd-resolve:x:102:104:systemd Resolver,,,:/run/systemd/resolve:/bin/false systemd-bus-proxy:x:103:105:systemd Bus Proxy,,,:/run/systemd:/bin/false syslog:x:104:108::/home/syslog:/bin/false _apt:x:105:65534::/nonexistent:/bin/false lxd:x:106:65534::/var/lib/lxd/:/bin/false messagebus:x:107:111::/var/run/dbus:/bin/false uuidd:x:108:112::/run/uuidd:/bin/false dnsmasq:x:109:65534:dnsmasq,,,:/var/lib/misc:/bin/false sshd:x:110:65534::/var/run/sshd:/usr/sbin/nologin pollinate:x:111:1::/var/cache/pollinate:/bin/false odoo:x:1000:27::/home/odoo:/bin/bash postgres:x:112:118:PostgreSQL administrator,,,:/var/lib/postgresql:/bin/bash root@PC-RENGUOQIANG:~# cat /etc/grou cat: /etc/grou: No such file or directory root@PC-RENGUOQIANG:~# cat /etc/group root:x:0: daemon:x:1: bin:x:2: sys:x:3: adm:x:4:syslog tty:x:5: disk:x:6: lp:x:7: mail:x:8: news:x:9: uucp:x:10: man:x:12: proxy:x:13: kmem:x:15: dialout:x:20: fax:x:21: voice:x:22: cdrom:x:24: floppy:x:25: tape:x:26: sudo:x:27: audio:x:29: dip:x:30: www-data:x:33: backup:x:34: operator:x:37: list:x:38: irc:x:39: src:x:40: gnats:x:41: shadow:x:42: utmp:x:43: video:x:44: sasl:x:45: plugdev:x:46: staff:x:50: games:x:60: users:x:100: nogroup:x:65534: systemd-journal:x:101: systemd-timesync:x:102: systemd-network:x:103: systemd-resolve:x:104: systemd-bus-proxy:x:105: input:x:106: crontab:x:107: syslog:x:108: netdev:x:109: lxd:x:110: messagebus:x:111: uuidd:x:112: mlocate:x:113: ssh:x:114: admin:x:115: docker:x:116: ssl-cert:x:117:postgres postgres:x:118: root@PC-RENGUOQIANG:~# cat /etc/passwd|grep -v nologin|grep -v halt|grep -v shutdown|awk -F":" '{ print $1"|"$3"|"$4 }'|more root|0|0 sync|4|65534 systemd-timesync|100|102 systemd-network|101|103 systemd-resolve|102|104 systemd-bus-proxy|103|105 syslog|104|108 _apt|105|65534 lxd|106|65534 messagebus|107|111 uuidd|108|112 dnsmasq|109|65534 pollinate|111|1 odoo|1000|27 postgres|112|118 root@PC-RENGUOQIANG:~#
参考文档：
http://www.cnblogs.com/wangkangluo1/archive/2011/09/23/2185977.html
http://www.cnblogs.com/xd502djj/archive/2011/11/23/2260094.html