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bzhao：
你也应该可以这样：（not tested）./rbtunnel ...
在Bash脚本中怎么关闭文件描述符？ -
bzhao：
如果有A进程原代码情况下，通过如下调用，把他的子进程继承关闭则 ...
在Bash脚本中怎么关闭文件描述符？ -
Master-Gao：
楼主咋没分析下源码呢？
我使用过的Linux命令之dirname - 截取给定路径的目录部分 -
jiedushi：
tail -F 就可以吧
Linux下实时跟踪log4j日志文件的bash脚本 - 增强了tail -f的功能 -
java_is_new：
新手学习了，就是不明白为一个网卡配多个ip有什么用
我使用过的Linux命令之ifconfig - 网络配置命令
MongoDB试用记录
MongoDB是一种著名的NoSQL数据库。
操作系统：RHEL5.4
MongoDB版本：2.0.0
下载MonoDB并解压
[root@sunrise16 setup]# wget "http://fastdl.mongodb.org/linux/mongodb-linux-i686-2.0.0.tgz"
--2011-10-20 12:56:36-- http://fastdl.mongodb.org/linux/mongodb-linux-i686-2.0.0.tgz
正在解析主机 fastdl.mongodb.org... 216.137.45.220, 216.137.45.22, 216.137.45.29, ...
Connecting to fastdl.mongodb.org|216.137.45.220|:80... 已连接。
已发出 HTTP 请求，正在等待回应... 200 OK
长度：37949452 (36M) [application/x-tar]
Saving to: `mongodb-linux-i686-2.0.0.tgz'
100%[==========================================================================================>] 37,949,452 44.6K/s in 8m 6s
2011-10-20 13:04:44 (76.2 KB/s) - `mongodb-linux-i686-2.0.0.tgz' saved [37949452/37949452]
[root@sunrise16 setup]#
[root@sunrise16 setup]# tar zxf mongodb-linux-i686-2.0.0.tgz
[root@sunrise16 setup]# cd mongodb-linux-i686-2.0.0
[root@sunrise16 mongodb-linux-i686-2.0.0]# ls
bin GNU-AGPL-3.0 README THIRD-PARTY-NOTICES
[root@sunrise16 mongodb-linux-i686-2.0.0]# cd bin
[root@sunrise16 bin]# ls
bsondump mongo mongod mongodump mongoexport mongofiles mongoimport mongorestore mongos mongosniff mongostat mongotop
启动mongod
[root@sunrise16 bin]# ./mongod
./mongod --help for help and startup options
Thu Oct 20 13:05:23
Thu Oct 20 13:05:23 warning: 32-bit servers don't have journaling enabled by default. Please use --journal if you want durability.
Thu Oct 20 13:05:23
Thu Oct 20 13:05:23 [initandlisten] MongoDB starting : pid=29178 port=27017 dbpath=/data/db/ 32-bit host=sunrise16
Thu Oct 20 13:05:23 [initandlisten]
Thu Oct 20 13:05:23 [initandlisten] ** NOTE: when using MongoDB 32 bit, you are limited to about 2 gigabytes of data
Thu Oct 20 13:05:23 [initandlisten] ** see http://blog.mongodb.org/post/137788967/32-bit-limitations
Thu Oct 20 13:05:23 [initandlisten] ** with --journal, the limit is lower
Thu Oct 20 13:05:23 [initandlisten]
Thu Oct 20 13:05:23 [initandlisten] db version v2.0.0, pdfile version 4.5
Thu Oct 20 13:05:23 [initandlisten] git version: 695c67dff0ffc361b8568a13366f027caa406222
Thu Oct 20 13:05:23 [initandlisten] build info: Linux domU-12-31-39-01-70-B4 2.6.21.7-2.fc8xen #1 SMP Fri Feb 15 12:39:36 EST 2008 i686 BOOST_LIB_VERSION=1_37
Thu Oct 20 13:05:23 [initandlisten] options: {}
Thu Oct 20 13:05:23 [initandlisten] exception in initAndListen: 10296 dbpath (/data/db/) does not exist, terminating
Thu Oct 20 13:05:23 dbexit:
Thu Oct 20 13:05:23 [initandlisten] shutdown: going to close listening sockets...
Thu Oct 20 13:05:23 [initandlisten] shutdown: going to flush diaglog...
Thu Oct 20 13:05:23 [initandlisten] shutdown: going to close sockets...
Thu Oct 20 13:05:23 [initandlisten] shutdown: waiting for fs preallocator...
Thu Oct 20 13:05:23 [initandlisten] shutdown: closing all files...
Thu Oct 20 13:05:23 [initandlisten] closeAllFiles() finished
Thu Oct 20 13:05:23 dbexit: really exiting now
[root@sunrise16 bin]#
根据屏幕上输出的信息，克制没有创建/data/db/目录。
[root@sunrise16 bin]# mkdir -p /data/db/
[root@sunrise16 bin]# ./mongod
./mongod --help for help and startup options
Thu Oct 20 13:06:31
Thu Oct 20 13:06:31 warning: 32-bit servers don't have journaling enabled by default. Please use --journal if you want durability.
Thu Oct 20 13:06:31
Thu Oct 20 13:06:31 [initandlisten] MongoDB starting : pid=29510 port=27017 dbpath=/data/db/ 32-bit host=sunrise16
Thu Oct 20 13:06:31 [initandlisten]
Thu Oct 20 13:06:31 [initandlisten] ** NOTE: when using MongoDB 32 bit, you are limited to about 2 gigabytes of data
Thu Oct 20 13:06:31 [initandlisten] ** see http://blog.mongodb.org/post/137788967/32-bit-limitations
Thu Oct 20 13:06:31 [initandlisten] ** with --journal, the limit is lower
Thu Oct 20 13:06:31 [initandlisten]
Thu Oct 20 13:06:31 [initandlisten] db version v2.0.0, pdfile version 4.5
Thu Oct 20 13:06:31 [initandlisten] git version: 695c67dff0ffc361b8568a13366f027caa406222
Thu Oct 20 13:06:31 [initandlisten] build info: Linux domU-12-31-39-01-70-B4 2.6.21.7-2.fc8xen #1 SMP Fri Feb 15 12:39:36 EST 2008 i686 BOOST_LIB_VERSION=1_37
Thu Oct 20 13:06:31 [initandlisten] options: {}
Thu Oct 20 13:06:31 [websvr] admin web console waiting for connections on port 28017
Thu Oct 20 13:06:31 [initandlisten] waiting for connections on port 27017
Ctrl+C
Thu Oct 20 13:06:40 got kill or ctrl c or hup signal 2 (Interrupt), will terminate after current cmd ends
Thu Oct 20 13:06:40 [interruptThread] now exiting
Thu Oct 20 13:06:40 dbexit:
Thu Oct 20 13:06:40 [interruptThread] shutdown: going to close listening sockets...
Thu Oct 20 13:06:40 [interruptThread] closing listening socket: 5
Thu Oct 20 13:06:40 [interruptThread] closing listening socket: 6
Thu Oct 20 13:06:40 [interruptThread] closing listening socket: 7
Thu Oct 20 13:06:40 [interruptThread] removing socket file: /tmp/mongodb-27017.sock
Thu Oct 20 13:06:40 [interruptThread] shutdown: going to flush diaglog...
Thu Oct 20 13:06:40 [interruptThread] shutdown: going to close sockets...
Thu Oct 20 13:06:40 [interruptThread] shutdown: waiting for fs preallocator...
Thu Oct 20 13:06:40 [interruptThread] shutdown: closing all files...
Thu Oct 20 13:06:40 [interruptThread] closeAllFiles() finished
Thu Oct 20 13:06:40 [interruptThread] shutdown: removing fs lock...
Thu Oct 20 13:06:40 dbexit: really exiting now
[root@sunrise16 bin]#
[root@sunrise16 bin]# ./mongod --journal
Thu Oct 20 13:06:50 [initandlisten] MongoDB starting : pid=29519 port=27017 dbpath=/data/db/ 32-bit host=sunrise16
Thu Oct 20 13:06:50 [initandlisten]
Thu Oct 20 13:06:50 [initandlisten] ** NOTE: when using MongoDB 32 bit, you are limited to about 2 gigabytes of data
Thu Oct 20 13:06:50 [initandlisten] ** see http://blog.mongodb.org/post/137788967/32-bit-limitations
Thu Oct 20 13:06:50 [initandlisten] ** with --journal, the limit is lower
Thu Oct 20 13:06:50 [initandlisten]
Thu Oct 20 13:06:50 [initandlisten] db version v2.0.0, pdfile version 4.5
Thu Oct 20 13:06:50 [initandlisten] git version: 695c67dff0ffc361b8568a13366f027caa406222
Thu Oct 20 13:06:50 [initandlisten] build info: Linux domU-12-31-39-01-70-B4 2.6.21.7-2.fc8xen #1 SMP Fri Feb 15 12:39:36 EST 2008 i686 BOOST_LIB_VERSION=1_37
Thu Oct 20 13:06:50 [initandlisten] options: { journal: true }
Thu Oct 20 13:06:50 [initandlisten] journal dir=/data/db/journal
Thu Oct 20 13:06:50 [initandlisten] recover : no journal files present, no recovery needed
Thu Oct 20 13:06:51 [initandlisten] preallocateIsFaster=true 7.24
Thu Oct 20 13:06:51 [initandlisten] preallocateIsFaster=true 7.26
Thu Oct 20 13:06:53 [initandlisten] preallocateIsFaster=true 7.22
Thu Oct 20 13:06:53 [initandlisten] preallocating a journal file /data/db/journal/prealloc.0
Thu Oct 20 13:07:58 [initandlisten] preallocating a journal file /data/db/journal/prealloc.1
220200960/268435456 82%
Thu Oct 20 13:09:03 [initandlisten] preallocating a journal file /data/db/journal/prealloc.2
146800640/268435456 54%
188743680/268435456 70%
251658240/268435456 93%
Thu Oct 20 13:10:08 [initandlisten] waiting for connections on port 27017
Thu Oct 20 13:10:08 [websvr] admin web console waiting for connections on port 28017
Thu Oct 20 13:11:08 [clientcursormon] mem (MB) res:12 virt:102 mapped:0
下面的日志内容是在启动一个mongo客户端之后产生的。
Thu Oct 20 13:11:50 [initandlisten] connection accepted from 127.0.0.1:36877 #1
Thu Oct 20 13:14:41 [FileAllocator] allocating new datafile /data/db/test.ns, filling with zeroes...
Thu Oct 20 13:14:41 [FileAllocator] creating directory /data/db/_tmp
Thu Oct 20 13:14:45 [FileAllocator] done allocating datafile /data/db/test.ns, size: 16MB, took 4.083 secs
Thu Oct 20 13:14:45 [FileAllocator] allocating new datafile /data/db/test.0, filling with zeroes...
Thu Oct 20 13:14:49 [FileAllocator] done allocating datafile /data/db/test.0, size: 16MB, took 4.07 secs
Thu Oct 20 13:14:49 [FileAllocator] allocating new datafile /data/db/test.1, filling with zeroes...
Thu Oct 20 13:14:49 [conn1] build index test.foo { _id: 1 }
Thu Oct 20 13:14:49 [conn1] build index done 0 records 0.361 secs
Thu Oct 20 13:14:51 [conn1] insert test.foo 10673ms
Thu Oct 20 13:14:57 [FileAllocator] done allocating datafile /data/db/test.1, size: 32MB, took 8.389 secs
Thu Oct 20 13:15:17 [clientcursormon] mem (MB) res:13 virt:199 mapped:32
Thu Oct 20 13:16:46 [FileAllocator] allocating new datafile /data/db/mydb.ns, filling with zeroes...
Thu Oct 20 13:16:51 [FileAllocator] done allocating datafile /data/db/mydb.ns, size: 16MB, took 4.262 secs
Thu Oct 20 13:16:51 [FileAllocator] allocating new datafile /data/db/mydb.0, filling with zeroes...
Thu Oct 20 13:16:55 [FileAllocator] done allocating datafile /data/db/mydb.0, size: 16MB, took 4.06 secs
Thu Oct 20 13:16:55 [FileAllocator] allocating new datafile /data/db/mydb.1, filling with zeroes...
Thu Oct 20 13:16:55 [conn1] build index mydb.things { _id: 1 }
Thu Oct 20 13:16:55 [conn1] build index done 0 records 0 secs
Thu Oct 20 13:16:55 [conn1] insert mydb.things 8330ms
Thu Oct 20 13:17:03 [FileAllocator] done allocating datafile /data/db/mydb.1, size: 32MB, took 8.142 secs
Thu Oct 20 13:17:23 [clientcursormon] mem (MB) res:13 virt:263 mapped:64
Thu Oct 20 13:22:23 [clientcursormon] mem (MB) res:13 virt:263 mapped:64
Thu Oct 20 13:24:08 [conn1] end connection 127.0.0.1:36877
Ctrl+C
Thu Oct 20 13:24:31 got kill or ctrl c or hup signal 2 (Interrupt), will terminate after current cmd ends
Thu Oct 20 13:24:31 [interruptThread] now exiting
Thu Oct 20 13:24:31 dbexit:
Thu Oct 20 13:24:31 [interruptThread] shutdown: going to close listening sockets...
Thu Oct 20 13:24:31 [interruptThread] closing listening socket: 6
Thu Oct 20 13:24:31 [interruptThread] closing listening socket: 7
Thu Oct 20 13:24:31 [interruptThread] closing listening socket: 8
Thu Oct 20 13:24:31 [interruptThread] removing socket file: /tmp/mongodb-27017.sock
Thu Oct 20 13:24:31 [interruptThread] shutdown: going to flush diaglog...
Thu Oct 20 13:24:31 [interruptThread] shutdown: going to close sockets...
Thu Oct 20 13:24:31 [interruptThread] shutdown: waiting for fs preallocator...
Thu Oct 20 13:24:31 [interruptThread] shutdown: lock for final commit...
Thu Oct 20 13:24:31 [interruptThread] shutdown: final commit...
Thu Oct 20 13:24:31 [interruptThread] shutdown: closing all files...
Thu Oct 20 13:24:31 [interruptThread] closeAllFiles() finished
Thu Oct 20 13:24:31 [interruptThread] journalCleanup...
Thu Oct 20 13:24:31 [interruptThread] removeJournalFiles
Thu Oct 20 13:24:31 [interruptThread] shutdown: removing fs lock...
Thu Oct 20 13:24:31 dbexit: really exiting now
[root@sunrise16 bin]#
[root@sunrise16 bin]#
使用mongo命令行工具访问MongoDB
[root@sunrise16 bin]# ./mongo
MongoDB shell version: 2.0.0
connecting to: test
Thu Oct 20 13:07:54 Error: couldn't connect to server 127.0.0.1 shell/mongo.js:84
exception: connect failed
[root@sunrise16 bin]# ./mongo
MongoDB shell version: 2.0.0
connecting to: test
Thu Oct 20 13:08:19 Error: couldn't connect to server 127.0.0.1 shell/mongo.js:84
exception: connect failed
[root@sunrise16 bin]# ./mongo
MongoDB shell version: 2.0.0
connecting to: test
Thu Oct 20 13:08:29 Error: couldn't connect to server 127.0.0.1 shell/mongo.js:84
exception: connect failed
[root@sunrise16 bin]# ./mongo
MongoDB shell version: 2.0.0
connecting to: test
> help
db.help() help on db methods
db.mycoll.help() help on collection methods
rs.help() help on replica set methods
help admin administrative help
help connect connecting to a db help
help keys key shortcuts
help misc misc things to know
help mr mapreduce
show dbs show database names
show collections show collections in current database
show users show users in current database
show profile show most recent system.profile entries with time >= 1ms
show logs show the accessible logger names
show log [name] prints out the last segment of log in memory, 'global' is default
use <db_name> set current database
db.foo.find() list objects in collection foo
db.foo.find( { a : 1 } ) list objects in foo where a == 1
it result of the last line evaluated; use to further iterate
DBQuery.shellBatchSize = x set default number of items to display on shell
exit quit the mongo shell
下面的测试内容来自 http://www.mongodb.org/display/DOCS/Quickstart+Unix
> db.foo.save({x:1})
> db.foo.find()
{ "_id" : ObjectId("4e9fae4127ed834a3f8d3b1a"), "x" : 1 }
下面的测试内容来自 http://www.mongodb.org/display/DOCS/Tutorial
> use mydb
switched to db mydb
> j={name:'zhy'}
{ "name" : "zhy" }
> t={t:3}
{ "t" : 3 }
> db.things.save(j)
> db.things.save(t)
> db.things.find()
{ "_id" : ObjectId("4e9faebe27ed834a3f8d3b1b"), "name" : "zhy" }
{ "_id" : ObjectId("4e9faecf27ed834a3f8d3b1c"), "t" : 3 }
> for (var i = 1; i <= 20; i++) db.things.save({x : 4, j : i});
> db.things.find()
{ "_id" : ObjectId("4e9faebe27ed834a3f8d3b1b"), "name" : "zhy" }
{ "_id" : ObjectId("4e9faecf27ed834a3f8d3b1c"), "t" : 3 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1d"), "x" : 4, "j" : 1 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1e"), "x" : 4, "j" : 2 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1f"), "x" : 4, "j" : 3 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b20"), "x" : 4, "j" : 4 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b21"), "x" : 4, "j" : 5 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b22"), "x" : 4, "j" : 6 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b23"), "x" : 4, "j" : 7 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b24"), "x" : 4, "j" : 8 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b25"), "x" : 4, "j" : 9 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b26"), "x" : 4, "j" : 10 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b27"), "x" : 4, "j" : 11 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b28"), "x" : 4, "j" : 12 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b29"), "x" : 4, "j" : 13 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2a"), "x" : 4, "j" : 14 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2b"), "x" : 4, "j" : 15 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2c"), "x" : 4, "j" : 16 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2d"), "x" : 4, "j" : 17 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2e"), "x" : 4, "j" : 18 }
has more
> it
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2f"), "x" : 4, "j" : 19 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b30"), "x" : 4, "j" : 20 }
> it
no cursor
> var cursor = db.things.find();
> while (cursor.hasNext()) printjson(cursor.next());
{ "_id" : ObjectId("4e9faebe27ed834a3f8d3b1b"), "name" : "zhy" }
{ "_id" : ObjectId("4e9faecf27ed834a3f8d3b1c"), "t" : 3 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1d"), "x" : 4, "j" : 1 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1e"), "x" : 4, "j" : 2 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1f"), "x" : 4, "j" : 3 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b20"), "x" : 4, "j" : 4 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b21"), "x" : 4, "j" : 5 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b22"), "x" : 4, "j" : 6 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b23"), "x" : 4, "j" : 7 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b24"), "x" : 4, "j" : 8 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b25"), "x" : 4, "j" : 9 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b26"), "x" : 4, "j" : 10 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b27"), "x" : 4, "j" : 11 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b28"), "x" : 4, "j" : 12 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b29"), "x" : 4, "j" : 13 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2a"), "x" : 4, "j" : 14 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2b"), "x" : 4, "j" : 15 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2c"), "x" : 4, "j" : 16 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2d"), "x" : 4, "j" : 17 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2e"), "x" : 4, "j" : 18 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2f"), "x" : 4, "j" : 19 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b30"), "x" : 4, "j" : 20 }
> db.things.find().forEach(printjson);
{ "_id" : ObjectId("4e9faebe27ed834a3f8d3b1b"), "name" : "zhy" }
{ "_id" : ObjectId("4e9faecf27ed834a3f8d3b1c"), "t" : 3 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1d"), "x" : 4, "j" : 1 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1e"), "x" : 4, "j" : 2 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1f"), "x" : 4, "j" : 3 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b20"), "x" : 4, "j" : 4 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b21"), "x" : 4, "j" : 5 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b22"), "x" : 4, "j" : 6 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b23"), "x" : 4, "j" : 7 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b24"), "x" : 4, "j" : 8 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b25"), "x" : 4, "j" : 9 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b26"), "x" : 4, "j" : 10 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b27"), "x" : 4, "j" : 11 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b28"), "x" : 4, "j" : 12 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b29"), "x" : 4, "j" : 13 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2a"), "x" : 4, "j" : 14 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2b"), "x" : 4, "j" : 15 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2c"), "x" : 4, "j" : 16 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2d"), "x" : 4, "j" : 17 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2e"), "x" : 4, "j" : 18 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2f"), "x" : 4, "j" : 19 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b30"), "x" : 4, "j" : 20 }
> var cursor = db.things.find();
> printjson(cursor[4]);
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1f"), "x" : 4, "j" : 3 }
> var arr = db.things.find().toArray();
> arr[5];
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b20"), "x" : 4, "j" : 4 }
> db.things.find({name:"mongo"}).forEach(printjson);
> db.things.find({name:"zhy"}).forEach(printjson);
{ "_id" : ObjectId("4e9faebe27ed834a3f8d3b1b"), "name" : "zhy" }
> db.things.find({x:4}).forEach(printjson);
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1d"), "x" : 4, "j" : 1 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1e"), "x" : 4, "j" : 2 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1f"), "x" : 4, "j" : 3 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b20"), "x" : 4, "j" : 4 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b21"), "x" : 4, "j" : 5 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b22"), "x" : 4, "j" : 6 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b23"), "x" : 4, "j" : 7 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b24"), "x" : 4, "j" : 8 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b25"), "x" : 4, "j" : 9 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b26"), "x" : 4, "j" : 10 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b27"), "x" : 4, "j" : 11 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b28"), "x" : 4, "j" : 12 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b29"), "x" : 4, "j" : 13 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2a"), "x" : 4, "j" : 14 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2b"), "x" : 4, "j" : 15 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2c"), "x" : 4, "j" : 16 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2d"), "x" : 4, "j" : 17 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2e"), "x" : 4, "j" : 18 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2f"), "x" : 4, "j" : 19 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b30"), "x" : 4, "j" : 20 }
> db.things.find({x:4}, {j:true}).forEach(printjson);
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1d"), "j" : 1 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1e"), "j" : 2 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1f"), "j" : 3 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b20"), "j" : 4 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b21"), "j" : 5 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b22"), "j" : 6 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b23"), "j" : 7 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b24"), "j" : 8 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b25"), "j" : 9 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b26"), "j" : 10 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b27"), "j" : 11 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b28"), "j" : 12 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b29"), "j" : 13 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2a"), "j" : 14 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2b"), "j" : 15 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2c"), "j" : 16 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2d"), "j" : 17 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2e"), "j" : 18 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b2f"), "j" : 19 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b30"), "j" : 20 }
> printjson(db.things.findOne({name:"mongo"}));
null
> printjson(db.things.findOne({name:"zhy"}));
{ "_id" : ObjectId("4e9faebe27ed834a3f8d3b1b"), "name" : "zhy" }
> var doc = db.things.findOne({_id:ObjectId("4c2209f9f3924d31102bd84a")});
> doc
null
> var doc = db.things.findOne({_id:ObjectId("4e9faf0f27ed834a3f8d3b28")});
> doc
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b28"), "x" : 4, "j" : 12 }
> db.things.find().limit(3);
{ "_id" : ObjectId("4e9faebe27ed834a3f8d3b1b"), "name" : "zhy" }
{ "_id" : ObjectId("4e9faecf27ed834a3f8d3b1c"), "t" : 3 }
{ "_id" : ObjectId("4e9faf0f27ed834a3f8d3b1d"), "x" : 4, "j" : 1 }
> quit
function () {
return nativeHelper.apply(quit_, arguments);
}
> exit
bye
[root@sunrise16 bin]#
顶
踩
评论
exception: connect failed
出现了这个问题。如何解决的？？
楼主没有贴出来
我随机启动会出这样的错，但直接启动没错，谁知是什么原因不
exception: connect failed
出现了这个问题。如何解决的？？
楼主没有贴出来
首先确认服务端是否启动了，
然后是服务器是否初始化好了，
这两种情况都会报这个错
exception: connect failed
出现了这个问题。如何解决的？？
楼主没有贴出来
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