A potential source of a full filesystem are large files left open but have been deleted. On Linux, a file may be deleted (removed/unlinked) while a process has it open. When this happens, the file is essentially invisible to other processes, but it still takes on physical space on the drive. Tools like du will not see it.

Sometimes top/htop don't give the fine-grained detail on memory usage you might need. Sum up the exact memory types you want

Here?s the idea: Submit a one-liner that returns a value or string usable for monitoring something. The more interesting/important, the better.

Tag your one-liners with CLFUContest to enter. Whether you?re participating or not, be sure to vote on the other submissions. The top 5 contest entries by vote count will receive a $10 Amazon gift certificate. On top of that, we?ll select our 3 favorite entries to receive $25 Amazon gift certificates. The prizes might even overlap! Feel free to enter as many times as you like. Check out the URL above for the fine print.

-Admin

centos list directories sorted by size

-A INPUT -p udp -m udp --dport 10000:66000 -m mac --mac-source 3E:D7:88:A6:66:8E -j ACCEPT

-A INPUT -p udp -m udp --dport 5060 -m mac --mac-source 3E:D7:88:A6:66:8E -j ACCEPT

-A INPUT -p tcp --dport 22 -m mac --mac-source 3E:D7:88:A6:66:8E -j ACCEPT

The difference between the original version provided and this one is that this one works rather than outputting a wget error

A more efficient way, with reversed order to put the focus in the big ones.

I always forget this one and find all kinds of complex solutions on google. Also works great while piping data. ex. 'cat data | process-data | tr -d "\"" > processed-data-without-quotes'

I had to compress it a bit to meet the 255 limit. See sample for full command (274)

usage:

ffgif foo.ext

Supports 3 arguments (optional)

ffgif filename seek_time time_duration scale

ffgif foo 10 5 320 will seek 10 seconds in, convert for 5 seconds at a 320 scale.

Default will convert whole video to gif at 320 scale.

Inspiration - http://superuser.com/questions/556029/how-do-i-convert-a-video-to-gif-using-ffmpeg-with-reasonable-quality/556031#556031

For all lines, sum the columns following the first one, and then print the first column plus the sum of all the other columns.

example input:

1,2,3,4,5

2,2,3,4,5

becomes

1,14

2,14

Save all output to a log.

This command will disable a guest user logon, this user don't have password to login in the system.

For times when netcat isn't available.

Will throw a Connection refused message if a port is closed.

Scriptable:

Take the header line from a comma-delimited CSV file and enumerate the fields.

.

First sed replaces all commas with newlines

Then sed quits (q) after the first line.

Finally, nl numbers all the lines

-F,

use , as field separator

gsub()

deletes all spaces

for(){}

loops over all input fields and print their index and value

exit

exit after first line

Useful to identify the field number in big CSV files with large number of fields. The index is the reference to use in processing with commands like 'cut' or 'awk' involved.