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Capture data in ASCII. 1500 bytes
Sniffing traffic on port 80 only the first 1500 bytes

check open ports without netstat or lsof

truncate deleted files from lsof
While the posted solution works, I'm a bit uneasy about the "%d" part. This would be hyper-correct approach: $ lsof|gawk '$4~/txt/{next};/REG.*\(deleted\)$/{sub(/.$/,"",$4);printf ">/proc/%s/fd/%s\n", $2,$4}' Oh, and you gotta pipe the result to sh if you want it to actually trim the files. ;) Btw, this approach also removes false negatives (OP's command skips any deleted files with "txt" in their name).

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"

See udev at work
See how your system works with pendrives/mice/monitors/whatever-you-can-plug-in. Use cases: see on which /dev/... your peripherals are, find out if a specific udev rule is being applied correctly.

parrallel execution of a command on remote hosts by ssh or rsh or ...
parrallel execution of a command on remote host by ssh or rsh or ... very useful for cluster management (software update)

Pipe stdout and stderr, etc., to separate commands
You can use [n]> combined with >(cmd) to attach the various output file descriptors to be the input of different commands.

Opens an explorer.exe file browser window for the current working directory or specified dir (Fixed)
This alternative either opens the current working directory by just issuing the open function in the commandline. Or you can specify what directory you would like to open. Example: open /cygdrive/c/Windows Usage: open [path] When no option is specified it will open the current working directory

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" }

Extend a logical volume to use up all the free space in a volume group


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