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Parallel file downloading with wget
xargs can be used in this manner to download multiple files at a time, and xargs will in this case run 10 processes at a time and initiate a new one when the number running falls below 10.

Change/Modify timestamp

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"

Clone current directory into /destination verbosely
Copy every file from current directory to destination preserving modification time.

Lurk what's going on on remote console

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" }

Verify if user account exists in Linux / Unix

Print a row of 50 hyphens

Securely destroy data on given device
Intentional hash in the beginning. May run a looong time. Wipes your data for real. Was meant to be /dev/urandom - I mistyped it. :-)

Show this month's calendar, with today's date highlighted
Explanation: * The date command evaluated to today's date with blank padded on the left if single digit * The grep command search and highlight today's date * The --before-context and --after-context flags displays up to 6 lines before and after the line containing today's date; thus completes the calendar. I have tested this command on Mac OS X Leopard and Xubuntu 8.10


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