Archive for the ‘Uncategorized’ Category

Socket connections uses file descriptor and it’s limited.

For Ubuntu, you can ulimit -a to see the current limit. (ulimit is not a binary command, so that no need sudo)

To increase the openfile to a maximum limit of 4096, you can ulimit -n 4096.

More than 4096 must edit the system file /etc/security/limits.conf.

In the current terminal, you will need su to make the settings take effect.


Turn off secure boot in your BIOS.

and then

sudo apt-get install linux-headers-$(uname -r|sed 's,[^-]*-[^-]*-,,') virtualbox

I have been using Amzon Cloud Drive to back up all my personal videos, but i noticed recently that many of my videos have a date taken as NO DATE or 1970.

After some research, i found the answer in this post. Amazon Cloud Drive seems to read the date from some video tags instead of the file creation date.

I wrote the below windows batch script to set those tags based on file creation date. The script is based on a system date format mm/dd/yyyy hh:ii tt.


SET filename="c:\your\video\file.mp4"

for %%a in (%filename%) do set filedatetime=%%~ta

ECHO %filedatetime%

set month=%filedatetime:~0,2%
set day=%filedatetime:~3,2%
set year=%filedatetime:~6,4%
set hour=%filedatetime:~11,2%
set minute=%filedatetime:~14,2%
set second=00
set pm=%filedatetime:~17,2%

if "%pm%" == "PM" (
set /a hour=1%hour%-100+12

if "%hour%" == "24" (
set /a hour=12

set finaldatetime="%year%:%month%:%day% %hour%:%minute%:%second%"

ECHO %finaldatetime%
:: set finaldatetime="2014:07:12 21:32:00"

exiftool %filename% -filecreatedate=%finaldatetime%
exiftool %filename% -filemodifydate=%finaldatetime%
:: exiftool %filename% -fileaccessdate=%finaldatetime%
exiftool %filename% -createdate=%finaldatetime%
exiftool %filename% -modifydate=%finaldatetime%
exiftool %filename% -trackcreatedate=%finaldatetime%
exiftool %filename% -trackmodifydate=%finaldatetime%
exiftool %filename% -mediacreatedate=%finaldatetime%
exiftool %filename% -mediamodifydate=%finaldatetime%