chrpak, a FORTRAN90 code which handles characters and strings.

The code began when I simply wanted to be able to capitalize a string. Now it has expanded to a number of interesting uses. Many unusual situations are provided for, including

Many of the routine names begin with the name of the data type they operate on:


The computer code and data files made available on this web page are distributed under the MIT license


chrpak is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version and an Octave version and a Python version.

Related Software and Data:

CAESAR, a FORTRAN90 code which can apply a Caesar Shift Cipher to a string of text.


rot13, a FORTRAN90 code which can encipher a string using the ROT13 cipher for letters, and the ROT5 cipher for digits.

Source Code:

Last revised on 07 September 2021.