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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"

find the longest command in your history

Email someone if a web page has been updated.
A cronjob command line to email someone when a webpages homepage is updated.

Virtualbox: setup hardware
where - memory 256 assign 256 Mb RAM - acpi on enable ACPI (mandatory if you use Winfog 2000 - ioapic off disable the IO APIC. Not useful if you use one CPU (on virtual machine or a 32 bit operative system). As ACPI, this switch is mandatory for Winbug 2000 - pae on enable the Phisical Address Extension how to use more than 4Gb of RAM on x86 CPU - hwvirtex on enables hardware virtualization extensions for microprocessors that have this feature (which should be also enabled in the BIOS of the motherboard) - nestedpaging on allows part of the processes of memory management hardware are made directly

LVM2 Reduce
Just the commands for the lvreduce I keep forgetting.

perl insert character on the first line on your file

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"

Rename files in batch

Create POSIX tar archive
tar(1) and cpio(1) are not fully platform agnostic, although their file formats are specified in POSIX.1-2001. As such, GNU tar(1) might not be able to extract a BSD tar(1) archive, and ivce versa. pax(1) is defined in POSIX.1-2001. To extract an archive: $ pax -rf archive.tar

Google voice recognition "API"
The FLAC audio must be encoded at 16000Hz sampling rate (SoX is your friend). Outputs a short JSON string, the actual speech is in the hypotheses->utterance, the accuracy is stored in hypotheses->confidence (ranging from 0 to 1). Google also accepts audio in some special speex format (audio/x-speex-with-header-byte), which is much smaller in comparison with losless FLAC, but I haven't been able to encode such a sample.


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