Commands by Redrocket (1)

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Get count of kilobytes brew cleanup would free

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" }

Grep syslog today last hour
Uses date to grep de logfile for today and uses it to get the last hour logs. Can be used to get last minute logs or today's logs.

Find the dates your debian/ubuntu packages were installed.
Find when debian packages were installed on a system.

trace the system calls made by a process (and its children)
strace can be invaluable in trying to figure out what the heck some misbehaving program is doing. There are number of useful flags to limit and control its output, and to attach to already running programs. (See also 'ltrace'.)

Update twitter with curl
Same as below, but no quotes are necessary when twitting more than one word

List detailed information about a ZIP archive
list zipfile info in long Unix ``ls -l'' format.

Create a bash script from last commands
In order to write bash-scripts, I often do the task manually to see how it works. I type ### at the start of my session. The function fetches the commands from the last occurrence of '###', excluding the function call. You could prefix this with a here-document to have a proper script-header. Delete some lines, add a few variables and a loop, and you're ready to go. This function could probably be much shorter...

most used commands in history (comprehensive)
Most of the "most used commands" approaches does not consider pipes and other complexities. This approach considers pipes, process substitution by backticks or $() and multiple commands separated by ; Perl regular expression breaks up each line using | or < ( or ; or ` or $( and picks the first word (excluding "do" in case of for loops) note: if you are using lots of perl one-liners, the perl commands will be counted as well in this approach, since semicolon is used as a separator

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"


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