File Utilities

FILUM is a FORTRAN90 library which can work with information in text files.


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


FILUM is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a Mathematica version and a MATLAB version and a Python version.

Related Data and Programs:

F90_FILES, programs which illustrate the use of files in the FORTRAN90 language.

FILE_MERGE, a FORTRAN90 program which merges two sorted files.

FILE_NAME_SEQUENCE, a FORTRAN90 program which demonstrates ways to generate a sequence of filenames that can be used when generating images for an animation.

FILE_ROW_REVERSE, a FORTRAN90 program which makes a copy of a file with the lines ("rows") in reverse order.

FILE_TRANSPOSE, a FORTRAN90 program which makes a "transposed" copy of a file, in which the I-th "word" of the J-th line becomes the J-th word of the I-th line.

FILES_MULTIPLE, a FORTRAN90 program which demonstrates how a program can open multiple output files at one time, and write data to any one specific file it chooses.

REFORMAT, a FORTRAN90 program which makes a copy of a file with a given number of "words" per line.


  1. Paul Bratley, Bennett Fox, Linus Schrage,
    A Guide to Simulation,
    Springer Verlag, pages 201-202, 1983.
  2. Tom Christiansen, Nathan Torkington,
    "8.6: Picking a Random Line from a File",
    Perl Cookbook, pages 284-285,
    O'Reilly, 1999.
  3. Pierre L'Ecuyer,
    Random Number Generation,
    in Handbook of Simulation,
    edited by Jerry Banks,
    Wiley Interscience, page 95, 1998.
  4. Bennett Fox,
    Algorithm 647: Implementation and Relative Efficiency of Quasirandom Sequence Generators,
    ACM Transactions on Mathematical Software,
    Volume 12, Number 4, pages 362-376, 1986.
  5. Philip Lewis, Allen Goodman, James Miller,
    A Pseudo-Random Number Generator for the System/360,
    IBM Systems Journal,
    Volume 8, pages 136-143, 1969.

Source Code:

Examples and Tests:

Files used for some of the tests include:

DATA_***.TXT is a short sequence of three files, each having 8 data items, 3 on the first line, 3 on the second, and 2 on the third line, to be examined by FILE_SEQUENCE_SIZE.

List of Routines:

You can go up one level to the FORTRAN90 source codes.

Last revised on 21 November 2011.