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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" }

Umount only the NFS related to 'string'
Sometimes, you have a lot of NFS in the server and you can't or shouldn't use umount -a. Whis this command, you only umount the fs related to the 'string'

Speed up builds and scripts, remove duplicate entries in $PATH. Users scripts are oftern bad: PATH=/apath:$PATH type of thing cause diplicate.
Thanks to the authors of: $ awk '!x[$0]++' and the author of: $ joinargs() { (local IFS="$1"; shift && echo "$*") } and others, we can have a fast Linux or android. IMPORTANT if you find a priority order problem in PATH you can push a path directory to the front without duplication as follows: $ PATH=/bin:$PATH then ... Check duplication with: $ echo $PATH|tr : '\n'|sort|uniq -d Finally do a very neat line by line list of $PATH: $ echo "${PATH//:/$'\n'} The speed up is very noticeable for android, and builds on Linux Ubantu are much faster with make and scripts. I will update the command on request. Timothy from SONY

Create multiple subfolders in one command.
Instead of typing separate commands to create various subfolders, we can create multiple subfolders by listing them between brackets and separated by commas.

rename a file to its md5sum

Show permissions of current directory and all directories upwards to /
Useful if a different user cannot access some directory and you want to know which directory on the way misses the x bit.

Send an email from the terminal when job finishes
Might as well include the status code it exited with so you know right away if it failed or not.

send DD a signal to print its progress
Sends the "USR1" signal every 1 second (-n 1) to a process called exactly "dd". The signal in some systems can be INFO or SIGINFO ... look at the signals list in: man kill

Rip a CD/DVD to ISO format.
An easy method to generate ISOs from CD/DVD media.

Record camera's output to a avi file
video.avi is the resulting file. Press Ctrl+c to stop the recording. You can change the OVC option to another to record into a different format.


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