Displays all the databases on MongoDB
Answer:
To display all the active databases on a MongoDB server, type
show dbs
To use it, like MySQL, try
use test
(Assume you need to use the test db)
Apr 012011
Linux Ask!
Mar 302011
Create an index on a document in MongoDB
Answer:
To create an index on a document in MongoDB, you can enter the shell and execute the statement like:
db.test.ensureIndex({ "fieldName": 1 })
(Assume you need to create index on fieldName of the test collection.)
That's easy?
Mar 282011
Swap last two characters in Bash
Answer:
Sometimes it is easy to mis-type characters in the wrong order, e.g. typed "sl" instead of "ls"
To swap it, use the little know Bash's trick: Ctrl + t
E.g.
# sl
[Ctrl + t]Mar 262011
Setting up a username in Mercurial
Answer:
To setup your Mercurial's username, you need to create the file .hgrc in your home folder,
e.g.
# touch ~/.hgrc
And add the following lines:
[ui]
username = John Doe <[email protected]>Mar 242011
Allow a remote IP for incoming connection in UFW (Uncomplicated firewall)
Answer:
To allow a remote IP for incoming connection in Ubuntu's UFW (Uncomplicated firewall), you can use the following command:
# sudo ufw allow from x.x.x.x
Of course you need to reload the firewall.
# sudo ufw reload
