Commands using cat (509)

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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" }

Lists installed kernels

Diff files over SSH
Sometimes you need to compare two config files on different servers. Put the file names into the above script and let 'er rip.

convert uppercase filenames in current directory to lowercase
as commented by Urk...

Print all open regular files sorted by the number of file handles open to each.
This command run fine on my Ubuntu machine, but on Red Hat I had to change the awk command to `awk '{print $10}'`.

a simple bash one-liner to create php file and call php function

C one-liners
$ /lib/ld-linux.so.2 is the runtime linker/loader for ELF binaries on Linux. =(cmd) is a zsh trick to take the output for the command "inside" it and save it to a temporary file. $ echo -e 'blah' | gcc -x c -o /dev/stdout - pipes the C source to gcc. -x c tells gcc that it's compiling C (which is required if it's reading from a pipe). -o /dev/stdout - tells it to write the binary to standard output and read the source from standard input. because of the the =() thing, the compiled output is stashed in a tempfile, which the loader then runs and executes, and the shell tosses the tempfile away immediately after running it.

See how many % of your memory firefox is using

Watch Al Jazeera Livestream directly in mplayer #jan25
One cannot call the high quality livestream directly, but command this gives you a session ID and the high quality stream. #egypt #jan25

check open ports without netstat or lsof


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