Commands by DevEd (2)

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Suppress output of loud commands you don't want to hear from

diff two unsorted files without creating temporary files
bash/ksh subshell redirection (as file descriptors) used as input to diff

Cleanup firefox's database.
Sqlite database keeps collecting cruft as time passes, which can be cleaned by the 'vacuum;' command. This command cleans up the cruft in all sqlite files relating to the user you have logged in as. This command has to be run when firefox is not running, or it will exit displaying the pid of the firefox running.

Add a Clock to Your CLI

Batch convert PNG to JPEG
Convert all PNG images in directory to JPEG using ImageMagick, and delete the old PNG images.

copy ACL of one file to another using getfacl and setfacl
If you copy windows file in e.g. cygwin the ACL might miss on the copied file. With this command you can copy the ACL of an existing file to another. WARNING: Existing ACL will get lost.

Watch how fast the files in a drive are being deleted
This can be useful when a large remove operation is taking place.

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Finding files with different extensions
This is the way how you can find header and cpp files in the same time.

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" }

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