REPL(Read Eval Print Loop:交互式解释器) 表示一个电脑的环境，类似 Window 系统的终端或 Unix/Linux shell，我们可以在终端中输入命令，并接收系统的响应。
交互式目录
[root@localhost ~]# ntpq
[root@localhost ~]# sqlite3
[root@localhost ~]# mysql -p
[root@localhost ~]# php -a
[root@localhost ~]# python
[root@localhost ~]# mail
[root@localhost ~]# yum shell
[root@localhost ~]# virsh
[root@localhost ~]# debugfs
[root@localhost ~]# gdb
[root@localhost ~]# ./redis-cli
[root@localhost ~]# ./mongo
[root@localhost ~]# bc
[root@localhost ~]# node(node.js)
[oracle@localhost ]$ sqlplus / as sysdba
[root@localhost ~]# ntpq ntpq> peers remote refid st t when poll reach delay offset jitter ============================================================================== +gus.buptnet.edu 202.112.10.60 3 u 17 64 377 88.144 32.547 5.601 +ntp.verd.co.id 202.162.32.12 3 u 85 64 336 209.770 4.300 167.134 *ktdns.cdnetwork 131.107.13.100 2 u 10 64 377 70.834 33.196 20.738 ntpq> ? ntpq commands: :config delay mreadvar readlist addvars exit mrl readvar associations help mrv rl authenticate host ntpversion rmvars ntpq> q [root@localhost ~]# [root@localhost ~]# sqlite3 SQLite version 3.6.20 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> .help .backup ?DB? FILE Backup DB (default "main") to FILE .bail ON|OFF Stop after hitting an error. Default OFF .databases List names and files of attached databases .dump ?TABLE? ... Dump the database in an SQL text format sqlite> .quit [root@localhost ~]# [root@84-monitor ~]# mysql -p Enter password: Welcome to the MySQL monitor. Commands end with ; or g. Your MySQL connection id is 1119677 Server version: 5.1.73 Source distribution mysql> ? mysql> quit Bye [root@84-monitor ~]# -bash-3.2$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.1.0 Production on Thu Feb 26 15:17:18 2015 Copyright (c) 1982, 2009, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP, Data Mining and Real Application Testing options SQL> ? HELP ---- Accesses this command line help system. Enter HELP INDEX or ? INDEX for a list of topics. You can view SQL*Plus resources at http://www.oracle.com/technology/tech/sql_plus/ and the Oracle Database Library at http://www.oracle.com/technology/documentation/ HELP|? [topic] SQL> quit Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP, Data Mining and Real Application Testing options -bash-3.2$ [root@84-monitor ~]# php -a Interactive shell php > php > b tab两次 BadFunctionCallException BadMethodCallException base64_decode base64_encode base_convert basename bin2hex bind_textdomain_codeset bindec bindtextdomain bzclose bzcompress bzdecompress bzerrno bzerror bzerrstr bzflush bzread bzwrite bzopen php > b php > quit [root@84-monitor ~]# [root@84-monitor ~]# python Python 2.6.6 (r266:84292, Jan 22 2014, 09:42:36) [GCC 4.4.7 20120313 (Red Hat 4.4.7-4)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> help Type help() for interactive help, or help(object) for help about object. >>> help() Welcome to Python 2.6! This is the online help utility. If this is your first time using Python, you should definitely check out the tutorial on the Internet at http://docs.python.org/tutorial/. Enter the name of any module, keyword, or topic to get help on writing Python programs and using Python modules. To quit this help utility and return to the interpreter, just type "quit". To get a list of available modules, keywords, or topics, type "modules", "keywords", or "topics". Each module also comes with a one-line summary of what it does; to list the modules whose summaries contain a given word such as "spam", type "modules spam". help> q You are now leaving help and returning to the Python interpreter. If you want to ask for help on a particular object directly from the interpreter, you can type "help(object)". Executing "help('string')" has the same effect as typing a particular string at the help> prompt. >>> exit() [root@84-monitor ~]#
[root@host02 ~]# mail
Heirloom Mail version 12.4 7/29/08. Type ? for help.
"/var/spool/mail/root": 6 messages 1 unread
1 Cron Daemon Thu Nov 8 17:07 22/791 "Cron <root@8A_2> /usr/local/nagios/cache-bin/client.sh localhost"
>U 2 Cron Daemon Thu Nov 8 17:08 22/790 "Cron <root@8A_2> /usr/local/nagios/cache-bin/client.sh localhost"
[root@84-monitor monitor]# yum shell
Loaded plugins: fastestmirror
Setting up Yum Shell
> ?
Usage: yum [options] COMMAND
[root@kvm1 qemu]# virsh
Welcome to virsh, the virtualization interactive terminal.
Type: 'help' for help with commands
'quit' to quit
virsh #
[root@104-c6 ~]# debugfs
debugfs 1.41.12 (17-May-2010)
debugfs:
debugfs: help
Available debugfs requests:
show_debugfs_params, params
Show debugfs parameters
open_filesys, open Open a filesystem
close_filesys, close Close the filesystem
feature, features Set/print superblock features
dirty_filesys, dirty Mark the filesystem as dirty
init_filesys Initialize a filesystem (DESTROYS DATA)
show_super_stats, stats Show superblock statistics
ncheck Do inode->name translation
icheck Do block->inode translation
change_root_directory, chroot
Change root directory
change_working_directory, cd
Change working directory
list_directory, ls List directory
show_inode_info, stat Show inode information
dump_extents, extents, ex
Dump extents information
link, ln Create directory link
unlink Delete a directory link
mkdir Create a directory
rmdir Remove a directory
rm Remove a file (unlink and kill_file, if appropriate)
kill_file Deallocate an inode and its blocks
clri Clear an inode's contents
freei Clear an inode's in-use flag
[root@localhost src]# ./redis-cli
127.0.0.1:6379> CONFIG SET protected-mode no
OK
127.0.0.1:6379> set aa bb
OK
127.0.0.1:6379> set ee 11
OK
127.0.0.1:6379> quit
[root@localhost src]#
[root@localhost ~]# gdb