F90_TO_F77
Conversion of FORTRAN90 to FORTRAN77

F90_TO_F77 is a FORTRAN90 program which assists in the conversion of a FORTRAN90 source code file to the FORTRAN77 format.

Only a few modifications are made; the user will surely have to go into the file and make further modifications by hand. The changes made by the program include:

• Input lines recognized as comments will be output with a first character of "c".
• Noncomment input lines which begin in column 1 or 2 will be indented to start in column 6.
• Other noncomment input lines will be indented 4 extra spaces.
• Noncomment output lines will automatically be broken into segments that are no more than 72 characters long, with excess information continued on the next line.

Usage:

f90_to_f77 input.f90 output.f

• input.f90 is the input FORTRAN90 file;
• output.f is the output file, which has been converted.

Licensing:

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

Languages:

F90_TO_F77 is available in a FORTRAN90 version.

Related Data and Programs:

F77_TO_F90, a FORTRAN90 program which converts a FORTRAN77 file to FORTRAN90 format, by Michael Metcalfe;

Source Code:

• f90_to_f77.f90, the source code.

Examples and Tests:

• file.f90, a sample FORTRAN90 file.
• file.f, the resulting FORTRAN77 file.

List of Routines:

• MAIN is the main program for F90_TO_F77.
• HANDLE copies an F90 file making an F77 version.
• GET_UNIT returns a free FORTRAN unit number.
• S_TAB_BLANKS replaces TAB characters by 6 spaces.
• TIMESTAMP prints the current YMDHMS date as a time stamp.

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