remove accents from input stream or a string
With a single argument, unaccent reads data from stdin, replaces accented letters by their unaccented equivalent and writes the result on stdout. If the second argument (‘string’) is provided unaccent transforms it by replacing accented letters by their unaccented equivalent. The result is printed on the standard output. The charset of the input string or the data read from stdin is specified by the ‘charset’ argument (ISO-8859-15 for instance). The output is printed using the same charset.
If the ‘expected’ argument is provided, the output string is compared to it. If they are not equal unaccent exits on error.
unaccent relies on the iconv(3) library to convert from the specified charset to UTF-16BE (or UTF-16 if UTF-16BE is not available). You should check the manual pages for available charsets. On GNU/Linux the command
shows all available charsets.
source code, unac-1.8.0.tar
P.S. the way to get the last version unac,
apt-get source unac