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Record audio and video from webcam using mencoder

Record audio to MP3 stream and video to MPEG-4 stream from webcam to AVI file using mencoder. Gives floating point exception in some mencoder versions.
This is sample output - yours may be different.
6

mencoder tv:// -tv driver=v4l2:width=800:height=600:device=/dev/video0:fps=30:outfmt=yuy2:forceaudio:alsa:adevice=hw.2,0 -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=1800 -ffourcc xvid -oac mp3lame -lameopts cbr=128 -o output.avi

ivalladt · 2009-09-15 19:46:06 5
View webcam output using mplayer

View webcam output using mplayer, with correct fps and outfmt settings according to my webcam model.
This is sample output - yours may be different.
5

mplayer tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0:fps=30:outfmt=yuy2

ivalladt · 2009-09-15 19:41:41 5
Execute all SQL files in a directory
This is sample output - yours may be different.
0

cat *.sql | mysql <db_name>

rehanift · 2009-09-15 17:28:35 3
Record audio and video from webcam using ffmpeg

Record from a webcam, audio using ALSA encoded as MP3, video as MPEG-4.
This is sample output - yours may be different.
5

ffmpeg -f alsa -r 16000 -i hw:2,0 -f video4linux2 -s 800x600 -i /dev/video0 -r 30 -f avi -vcodec mpeg4 -vtag xvid -sameq -acodec libmp3lame -ab 96k output.avi

ivalladt · 2009-09-15 17:03:25 5
convert a,b,c to ('a','b','c') for use in SQL in-clauses
This is sample output - yours may be different.
1

echo a,b,c | sed -e s/,/\',\'/g -e s/^/$\'/ -e s/$/\'$/

sharfah · 2009-09-15 15:52:01 5
Remove all files but one starting with a letter(s)

Remove everything in current directory except files starting with "ca".
This is sample output - yours may be different.
1

rm -rf [a-bd-zA-Z0-9]* c[b-zA-Z0-9]*

arcege · 2009-09-15 14:22:56 7
Extract audio track from a video file using mencoder

Extracts an MP3 encoded audio stream from an input video file.
This is sample output - yours may be different.
3

mencoder -of rawaudio -ovc copy -oac mp3lame -o output.mp3 input.avi

ivalladt · 2009-09-15 11:28:01 3
Substitute audio track of video file using mencoder

Creates a new video file with video stream copied from input file and a different audio stream
This is sample output - yours may be different.
2

mencoder -ovc copy -audiofile input.mp3 -oac copy input.avi -o output.avi

ivalladt · 2009-09-15 11:26:05 3
Remove sound from video file using mencoder

Remove sound from input video file, output video stream is copied from input video stream, with no audio.
This is sample output - yours may be different.
1

mencoder -ovc copy -nosound input.avi -o output.avi

ivalladt · 2009-09-15 11:22:51 6
Fix UTF-8 text files misinterpreted as ISO 8859-1 due to Byte Order Mark (BOM) of the Unicode Standard.

Fixes the faulty files with perl, which may exist on more platforms
This is sample output - yours may be different.
0

perl -i -pe 's/\xef\xbb\xbf//g' <file>

pfredrik · 2009-09-15 11:22:43 4

This command creates tar zip of a directory and its sub-directories. Show Sample Output

tar cvfz dir_name.tgz dir/

unixmonkey6220 · 2009-09-15 10:20:20 4

Happy Days

AFAIR this is the wording ;)
This is sample output - yours may be different.
5

echo {'1,2,3',4}" o'clock" ROCK

danam · 2009-09-15 10:12:49 11
Incase you miss the famous 'C:\>' prompt
This is sample output - yours may be different.
1

export PS1='C:${PWD//\//\\\}>'

jldbasa · 2009-09-15 10:06:25 4
Find UTF-8 text files misinterpreted as ISO 8859-1 due to Byte Order Mark (BOM) of the Unicode Standard.

Same thing, only "head" instead of grep/egrep.. Show Sample Output
This is sample output - yours may be different.
```
Match: ./wps.ear/wps.war/themes/html/QPG/pageHeader.html
```
0

find -type f |while read a;do [ "`head -c3 -- "${a}"`" == $'\xef\xbb\xbf' ] && echo "Match: ${a}";done

pfredrik · 2009-09-15 08:43:21 3
Backup files older than 1 day on /home/dir, gzip them, moving old file to a dated file.

Useful for backing up old files, custom logs, etc. via a cronjob. Show Sample Output
This is sample output - yours may be different.
```
-rw-rw-r--    1 root     root        46705 Sep 13 14:30 file2.rpm
-rw-rw-r--    1 rms      rms         46705 Sep 13 14:30 file22.rpm

-rw-rw-r--    1 root     root        44227 Sep 13 14:30 file2.rpm_2009-09-15.gz
-rw-rw-r--    1 rms      rms         44228 Sep 13 14:30 file22.rpm_2009-09-15.gz
```
9

find /home/dir -mtime +1 -print -exec gzip -9 {} \; -exec mv {}.gz {}_`date +%F`.gz \;

sagan · 2009-09-15 06:49:59 10
Setting reserved blocks percentage to 1%

According to tune2fs manual, reserved blocks are designed to keep your system from failing when you run out of space. Its reserves space for privileged processes such as daemons (like syslogd, for ex.) and other root level processes; also the reserved space can prevent the filesystem from fragmenting as it fills up. By default this is 5% regardless of the size of the partition. http://www.ducea.com/2008/03/04/ext3-reserved-blocks-percentage/
This is sample output - yours may be different.
2

sudo tune2fs -m 1 /dev/sda4

bassel · 2009-09-14 21:11:55 5
Testing hard disk reading speed
This is sample output - yours may be different.
13

hdparm -t /dev/sda

bassel · 2009-09-14 21:04:08 9
Check variable has been set

Works in all shells. Does not require a test. Handles like an assertion. Show Sample Output
This is sample output - yours may be different.
```
sh: VAR: unset variable
```
-1

: ${VAR:?unset variable}

arcege · 2009-09-14 19:41:01 4
erase content from a cdrw
This is sample output - yours may be different.
1

cdrecord -v -blank=all -force

eastwind · 2009-09-14 19:21:15 7
burn an iso to cd or dvd
This is sample output - yours may be different.
-1

cdrecord -v path_to_iso_image.iso

eastwind · 2009-09-14 19:20:12 4
random xkcd comic

i sorta stole this from http://www.shell-fu.org/lister.php?id=878#MTC_form but it didn't work, so here it is, fixed. --- updated to work with jpegs, and to use a fancy positive look behind assertion.
This is sample output - yours may be different.
6

display "$(wget -q http://dynamic.xkcd.com/comic/random/ -O - | grep -Po '(?<=")http://imgs.xkcd.com/comics/[^"]+(png|jpg)')"

grokskookum · 2009-09-14 18:40:14 5
Check variable has been set
This is sample output - yours may be different.
1

[ -z "$VAR" ] && echo "VAR has not been set" && exit 1

sharfah · 2009-09-14 17:03:16 4
Happy Days

This never gets old Show Sample Output
This is sample output - yours may be different.
```
you'll just have to see now wont you
```
4

echo {1..3}" o'clock" ROCK

JackiesJungle · 2009-09-14 15:39:07 5
view file content with echo

another replacement for cat.
This is sample output - yours may be different.
-2

echo "$(</etc/issue)"

mobidyc · 2009-09-14 09:44:35 34
search for a file in PATH

Also searches for aliases and shell builtins Show Sample Output
This is sample output - yours may be different.
```
root@fs3:~# type nvgui
nvgui is /usr/bin/nvgui
root@serv:~# type rm
rm is /bin/rm
root@fs3:~# type alias
alias is a shell builtin
root@serv:~# 
```
4

type <filename>

danam · 2009-09-14 09:37:23 5
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Get just the IP for a hostname

Display the output of a command from the first line until the first instance of a regular expression.

If BREs can be used, this sed version will also get the job done.

retab in vim, tab to space or space to tab, useful in python

usage： :[rang]ret[!][tabstop value] python is indent sensitive, after command :set list you may see your codes are mixed with tab and space ret can help you to convert space to tab or tab to space

Convert seconds to [DD:][HH:]MM:SS

Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

On Mac OS X, runs System Profiler Report and e-mails it to specified address.

Replace "user@domain.com" with the target e-mail address. Thanks to alediaz for "$HOSTNAME" which is very useful when running the command with Apple Remote Desktop to multiple machines simultaneously.

write text or append to a file

If you just want to write or append some text to a file without having to run a text editor, run this command. After running the command, start typing away. To exit, type . on a line by itself. Replacing the >> with a single > will let you overwrite your file.

Schedule Nice Background Commands That Won't Die on Logout - Alternative to nohup and at

Check out the usage of 'trap', you may not have seen this one much. This command provides a way to schedule commands at certain times by running them after sleep finishes sleeping. In the example 'sleep 2h' sleeps for 2 hours. What is cool about this command is that it uses the 'trap' builtin bash command to remove the SIGHUP trap that normally exits all processes started by the shell upon logout. The 'trap 1' command then restores the normal SIGHUP behaviour. It also uses the 'nice -n 19' command which causes the sleep process to be run with minimal CPU. Further, it runs all the commands within the 2nd parentheses in the background. This is sweet cuz you can fire off as many of these as you want. Very helpful for shell scripts.

Do the last command, but say 'y' to everything

I doubt this works with other than bash, but then again, I havent tried. The 'yes' utility is very simple, it outputs a hell of a lot of 'y's to standard input. The '!!' command means 'the last command'. So this one-lines inputs a lot of y's into the last command, aggressively agreeing to everything. For instance, when doing apt-get.

Convert an existing Git repo to a bare repo

If you want to turn a Git repo into the origin that folks can push to, you should make it a bare repository. See: http://stackoverflow.com/questions/2199897/git-convert-normal-to-bare-repository

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"

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