CHRPAK
routines for handling character strings

CHRPAK is a FORTRAN77 library which can handle characters and strings of characters.

CHRPAK 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

• string '31.2' <=> numeric value 31.2;
• uppercase <=> lowercase;
• removal of control characters or blanks;
• sorting, merging, searching.

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

• B4 - a 4 byte word;
• CH - a character;
• CHVEC - a vector of characters;
• DEC - a decimal fraction;
• DIGIT - a character representing a numeric digit;
• I4 - an integer ( kind = 4 );
• R4 - a real ( kind = 4 );
• R8 - a real ( kind = 8 );
• RAT - a ratio I/J;
• S - a string;
• SVEC - a vector of strings;
• SVECI - a vector of strings, implicitly capitalized;

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Related Data and Programs:

CHRPAK is also available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.

Reference:

1. Carl Branden, John Tooze,
   Introduction to Protein Structure,
   Second Edition,
   Garland Publishing, 1999,
   ISBN: 0815323050,
   LC: QP551.B7635.
2. Paul Bratley, Bennett Fox, Linus Schrage,
   A Guide to Simulation,
   Second Edition,
   Springer, 1987,
   ISBN: 0387964673,
   LC: QA76.9.C65.B73.
3. IEEE Standards Committee 754,
   IEEE Standard for Binary Floating Point Arithmetic,
   ANSI/IEEE Standard 754-1985,
   SIGPLAN Notices,
   Volume 22, Number 2, 1987, pages 9-25.
4. Donald Knuth,
   The Art of Computer Programming,
   Volume 3, Sorting and Searching,
   Second Edition,
   Addison Wesley, 1998,
   ISBN: 0201896850,
   LC: QA76.6.K64.
5. Albert Nijenhuis, Herbert Wilf,
   Combinatorial Algorithms for Computers and Calculators,
   Academic Press, 1978,
   ISBN: 0-12-519260-6,
   LC: QA164.N54.

Source Code:

• chrpak.f, the source code.
• chrpak.csh, commands to compile the source code.

Examples and Tests:

• chrpak_prb.f, a sample calling program.
• chrpak_prb.csh, commands to compile and run the sample program.
• chrpak_prb_output.txt, the output file.

List of Routines:

• A_TO_I4 returns the index of an alphabetic character.
• CH_CAP capitalizes a single character.
• CH_EQI is a case insensitive comparison of two characters for equality.
• CH_IS_DIGIT returns TRUE if a character is a decimal digit.
• CH_IS_SPACE is TRUE if a character is a whitespace character.
• CH_IS_UPPER is TRUE if CH is an upper case letter.
• CH_LOW lowercases a single character.
• CH_SWAP swaps two characters.
• CH_TO_DIGIT returns the integer value of a base 10 digit.
• CH_TO_DIGIT_HEX returns the integer value of a hexadecimal digit.
• CH_TO_DIGIT_OCT returns the integer value of an octal digit.
• CH_TO_ROT13 converts a character to its ROT13 equivalent.
• CH_TO_SCRABBLE returns the Scrabble index of a character.
• CH_UNIFORM returns a scaled pseudorandom CH.
• DIGIT_INC increments a decimal digit.
• DIGIT_TO_CH returns the character representation of a decimal digit.
• FILE_NAME_INC generates the next filename in a series.
• HEX_TO_I4 converts a hexadecimal string to its integer value.
• HEX_TO_S converts a hexadecimal string into characters.
• I4_LENGTH computes the number of characters needed to print an integer.
• I4_SWAP switches two I4's.
• I4_TO_A returns the I-th alphabetic character.
• I4_UNIFORM returns a scaled pseudorandom I4.
• I4VEC_INDICATOR sets an I4VEC to the indicator vector.
• I4VEC_PRINT prints an I4VEC.
• R4_UNIFORM_01 returns a unit pseudorandom R4.
• S_ADJUSTL flushes a string left.
• S_ADJUSTR flushes a string right.
• S_BLANK_DELETE removes blanks from a string, left justifying the remainder.
• S_BLANKS_DELETE replaces consecutive blanks by one blank.
• S_EQI is a case insensitive comparison of two strings for equality.
• S_LEN_TRIM returns the length of a string to the last nonblank.
• S_LOW replaces all uppercase letters by lowercase ones.
• S_TO_I4 reads an I4 from a string.
• S_TO_I4VEC reads an I4VEC from a string.
• S_TO_R8 reads an R8 from a string.
• S_TO_R8VEC reads an R8VEC from a string.
• S_WORD_COUNT counts the number of "words" in a string.
• S_WORD_EXTRACT_FIRST extracts the first word from a string.
• TIMESTAMP prints out the current YMDHMS date as a timestamp.

You can go up one level to the FORTRAN77 source codes.