Commands by DaveQB

Commands by DaveQB (9)

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Console clock

A console clock with the current time. Show Sample Output
This is sample output - yours may be different.
```
Every 1.0s: date "+%T"                                                                                                                                                                    

11:33:02
```
4

watch -n1 'date "+%T"'

DaveQB · 2011-02-16 00:33:51 0
find the device when you only know the mount point

Shorter way to find the device for a given mountpoint
This is sample output - yours may be different.
-1

df /media/mountpoint |egrep -o '^[/a-z0-9]*'

DaveQB · 2011-01-24 21:14:55 0
Multi line grep using sed and specifying open/close tags

This line does not include your closing tag in the output. Show Sample Output
This is sample output - yours may be different.
```
daveqb@localhost /tmp $
cat test
one two three
four
five
six
seven

daveqb@localhost /tmp $
sed '/'"four"'/,/'"six"'/{/'"six"'/d;p};d' "test"
four
five
```
1

sed '/'"<opening tag>"'/,/'"<closing tag>"'/{/'"<closing tag>"'/d;p};d' "<file>"

DaveQB · 2010-11-08 21:43:00 0
Remove all the files except abc in the directory

Finds all files in the current directory and deletes them besides file called "abc" Show Sample Output
This is sample output - yours may be different.
```
nil
```
5

find * -maxdepth 1 -type f ! -name abc -delete

DaveQB · 2010-07-19 00:29:59 0
Remove "ssh host" from known hosts file.

I have this as a file called deletekey in my ~/bin. Makes life a little easier.
This is sample output - yours may be different.
-13

echo "${1}" | egrep '^[[:digit:]]*$' ; if [ "$?" -eq 0 ] ; then sed -i "${1}"d $HOME/.ssh/known_hosts ; else printf "\tYou must enter a number!\n\n" ; exit 1 ; fi

DaveQB · 2010-07-11 23:09:11 0
Print number of mb of free ram

Here we instead show a more real figure for how much free RAM you have when taking into consideration buffers that can be freed if needed. Unix machines leave data in memory but marked it free to overwrite, so using the first line from the "free" command will mostly give you back a reading showing you are almost out of memory, but in fact you are not, as the system can free up memory as soon as it is needed. I just noticed the free command is not on my OpenBSD box. Show Sample Output
This is sample output - yours may be different.
```
4920
```
3

free -m | awk '/buffer/ {print $4}'

DaveQB · 2010-06-27 23:30:27 3
Email someone if a web page has been updated.

A cronjob command line to email someone when a webpages homepage is updated.
This is sample output - yours may be different.
3

cd /some/empty/folder/website_diffs/sitename && wget -N http://domain.com/ 2>&1 |grep -q "o newer" || printf "Sites web page appears to have updated.\n\nSuggest you check it out.\n\n"|mail -s "Sites page updated." david@email.com

DaveQB · 2010-05-09 07:28:42 0
Bash function to see what the day ends in

A command to find out what the day ends in. Can be edited slightly to find out what "any" output ends in. NB: I haven't tested with weird and wonderful output. Show Sample Output
This is sample output - yours may be different.
```
y
```
0

date +%A | cut -c $(( $(date +%A | wc -c) - 1 ))

DaveQB · 2010-04-07 00:23:15 2
Convert a videos audio track to ogg vorbis.

Assumes you have ffmpeg and oggenc. Similar to other scripts here, but this time outputting to Ogg Vorbis. I added the variable assignment for a nice output name. This is part of an interactive bash script I have with a few little multimedia tasks in it. http://www.dward.us/software/VSAK.sh
This is sample output - yours may be different.
1

INPUT=<input_video> && ffmpeg -i "$INPUT" -vn -f wav - | oggenc -o ${INPUT%%.*}.ogg -

DaveQB · 2009-05-19 07:57:43 0

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Kill google chrome process

This one liner is to kill all google chrome tabs. This works similar to $ killall firefox command which is to kill all firefox processes.

coloured tail

tail with coloured output with the help of perl - need more colours? here is a colour table: http://www.tuxify.de/?p=23

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Get a range of SVN revisions from svn diff and tar gz them

Handy when you need to create a list of files to be updated when subversion is not available on the remote host. You can take this tar file, and upload and extract it where you need it. Replace M and N with the revisions specific to yours. Make sure you do this from an updated (svn up) working directory.

Serve current directory tree at http://$HOSTNAME:8000/

Advanced python tracing

Trace python statement execution and syscalls invoked during that simultaneously

Like top, but for files

list block devices

Shows all block devices in a tree with descruptions of what they are.

One-liner to generate Self-Signed SSL Certificate+Key without any annoying prompts or CSRs

Handy if you want to quickly generate a self-signed certificate. Also can be used in your automated scripts for generating quick-use certificates.

Hide or show Desktop Icons on MacOS

Hides all Files and Folders on the MacOS Desktop. To show files and folders, type "true" instead of "false". "Finder" at the end is case sensitive, "finder" doesn’t work

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