How to completely uninstall a package in Ubuntu/Debian?
Answer:
To completely uninstall a package in Ubuntu/Debian, you can use the command below:
# sudo apt-get --purge remove PACKAGE
That's it.
Oct 242010
Linux Ask!
Oct 232010
How to echo a tab in bash?
Answer:
In Bash script, if you want to print out unprintable characters such as tab, you need to use -e flag together with the echo command.
E.g.
echo -e "\tfoo\tbar"Oct 222010
Send ARP REQUEST to a neighbour host in Linux
Answer:
The arping command allow you to Ping destination on device interface by ARP packets, using source address source.
E.g.
# arping -U 192.168.1.5
The above command send an Unsolicited ARP request to update neighbours' ARP caches.
Oct 212010
How to show the warnings during mysqlimport
Answer:
When you use mysqlimport to import data from text file, the number of warnings will be displayed at the end of import. But there is no way to show the actual warnings message.
To show the warnings, the only method is get into the mysql client to insert, instead of using mysqlimport.
E.g.
mysql> LOAD DATA INFILE '/tmp/user.csv' REPLACE INTO TABLE user
Query OK, 100000 rows affected, 192 warnings (2.30 sec)
mysql> SHOW WARNINGS;
Oct 202010
How to modify a single character in a string in Python?
Answer:
Strings in Python are immutable, if you want to modify a single character in a string in Python, you need to do something like the following...
a = list("foo")
a[2] = 'x'
print ''.join(a)
The string "fox " will be printed out.
