Debian Package of the Day (static archived copy)

Article submitted by Todd Troxell. Please help DPOTD by submitting good articles about software you like!

A package I find useful is cpipe. It is simple tool you can use to determine the throughput of a pipe. Potential uses of cpipe might include determining the speed of:

• backups that use tar and dd
• your system’s pseudo-random number generator (see below)
• an OpenSSH tunnel or OpenVPN between two systems on the Internet

For example, to determine the speed at which you can read from /dev/urandom and write to /dev/null, run:

$ cpipe -vt < /dev/urandom > /dev/null

This will produce output like the following:

thru:  56.045ms at    2.2MB/s (   1.3MB/s avg)    1.1MB
thru:  74.936ms at    1.7MB/s (   1.3MB/s avg)    1.2MB
thru:  21.748ms at    5.7MB/s (   1.4MB/s avg)    1.4MB
thru:  90.131ms at    1.4MB/s (   1.4MB/s avg)    1.5MB

You can also use it to measure read times, write times and to limit throughput:

$ cat /dev/zero | cpipe -s 100 -vt > /dev/null
thru: 1256.079ms at  101.9kB/s ( 101.9kB/s avg)  128.0kB
thru: 1259.942ms at  101.6kB/s ( 101.7kB/s avg)  256.0kB
thru: 1260.469ms at  101.5kB/s ( 101.7kB/s avg)  384.0kB

Cpipe’s upstream homepage is http://cpipe.berlios.de/. It is written by Harald Kirsch. It has been available in Debian since (at least) sarge, and Ubuntu since (at least) dapper.