Head

From PortaWiki

The GNU folks managed to break some versions of head(1). Versions from coreutils version ??? to 5.3.0 inclusive do not accept numeric arguments (eg "head -1"). 5.3.1 and newer are OK.

This is apparently an attempt to adhere to the newer POSIX.1 standards (SuSv3) which specify that numeric arguments be preceeded by -n (eg "head -n 1"), however those standards do not preclude a conforming implementation from accepting the older form (in fact, this is specifically addressed in the POSIX.1 FAQ Q15).

The workaround is to set (and export) the environment variable _POSIX2_VERSION=199209