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Print every Nth line
Sometimes commands give you too much feedback. Perhaps 1/100th might be enough. If so, every() is for you. $ my_verbose_command | every 100 will print every 100th line of output. Specifically, it will print lines 100, 200, 300, etc If you use a negative argument it will print the *first* of a block, $ my_verbose_command | every -100 It will print lines 1, 101, 201, 301, etc The function wraps up this useful sed snippet: $ ... | sed -n '0~100p' don't print anything by default $ sed -n starting at line 0, then every hundred lines ( ~100 ) print. $ '0~100p' There's also some bash magic to test if the number is negative: we want character 0, length 1, of variable N. $ ${N:0:1} If it *is* negative, strip off the first character ${N:1} is character 1 onwards (second actual character).

Display screen window number in prompt
Add this to your $HOME/.bashrc file. It will only set this prompt if it is running inside screen ($WINDOW var is set) Looks like this... $ ion@atomos:~[2]$

make a list of movies(.m3u).

tar the current directory wihtout the absolute path
tars the current directory (and its children) in an archive of the same name (plus ".tar" :)) in the parent directory without the absolute path, so that when the archive is extracted, only the current directory name is created for the path. Assumes bash/zsh.

Check which files are opened by Firefox then sort by largest size.
Check which files are opened by Firefox then sort by largest size (in MB). You can see all files opened by just replacing grep to "/". Useful if you'd like to debug and check which extensions or files are taking too much memory resources in Firefox.

get a rough estimate about how much disk space is used by all the currently installed debian packages
The vaule is expressed in megabytes

Kill a process by its partial name (BSD/Mac)
This kills Activity Monitor

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" }

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"

List all packages by installed size (Bytes) on rpm distros


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