"Olson, Arthur David \(NIH/NCI\) [E]" <olsona@dc37a.nci.nih.gov> writes:
In the 64-bit versions of the time zone data files, all files end with a line of text that's either blank (rarely) or is a POSIX-style time-zone specifier for future times; judicious use of "tail -1" and "sed" in a shell script can produce a list of time zone abbreviations.
It's not a text file, right? So "tail -1" is a bit dubious, as POSIX 1003.1-2004 <http://www.opengroup.org/susv3/utilities/tail.html> says that the input to "tail" must be a text file unless -c is specified. Also, this is more controversial, but POSIX says portable scripts are supposed to use "tail -n 1" rather than "tail -1". There are a few implementations that don't support the obsolete "tail -1" form.