g77 - GNU Project FORTRAN Compiler

This section provides a quick introduction of g77, the GNU Project FORTRAN Compiler. A sample session of compilation, linking and executing a FORTRAN 77 program is also provided.

"g77" is a free and open source compiler for FORTRAN 77 language developed by the GNU project. "g77" is actually a front-end program that calls "gcc", the GNU C Compiler to compile FORTRAN 77 programs.

Here is an interesting compilation, linking and execution session of a FORTRAN 77 program using "g77" on a Linux system:

%cat swap.f
      SUBROUTINE SWAP(X, Y, N)
      DIMENSION X(*), Y(*)
      DO 100 I = 1, N
         T = X(I)
         X(I) = Y(I)
         Y(I) = T
  100 CONTINUE
      END

%g77 -c swap.f -o swap.o -v
g77 version 0.5.21
 gcc -c -xf77 swap.f -o swap.o -v
Reading specs from /usr/lib/gcc-lib/i486.../2.7.2.3/specs
gcc version 2.7.2.3
...

%cat test.f
      PROGRAM TEST
      DIMENSION A(10), B(10)
      M = 7
      DO 100 I = 1, M
         A(I) = 10.0 + RAND()
         B(I) = 20.0 + RAND()
  100 CONTINUE
      CALL SWAP(A, B, M)
      DO 200 I = 1, M
         WRITE(6,10) A(I), B(I)
  200 CONTINUE
   10 FORMAT(2F7.2)
      END

%g77 -c testf -o test.o

%g77 test.o swap.o -o test -v
g77 version 0.5.21
 gcc -c -xf77 swap.f -o swap.o -v
...

%./test
  20.54  10.13
  20.58  10.41
  20.96  10.17
  20.29  10.69
  20.11  10.56
  20.71  10.82
  20.48  10.84

Notice that:

Table of Contents

 About This Book

1957 - FORTRAN Language Developed by IBM

 What Is FORTRAN?

 Storing FORTRAN Program Code on Punch Cards

 FORTRAN 66 - Example Program Code

 FORTRAN 77 - Example Program Code

g77 - GNU Project FORTRAN Compiler

 Fortran 90 - Example Program Code

 1970 - UNIX Operating System Developed by AT&T Bell Labs

 1971 - FTP Protocol Created by Abhay Bhushan

 1972 - C Language Developed by Dennis Ritchie

 1976 - vi Text Editor Developed by Bill Joy

 1977 - Apple II Designed by Steve Jobs and Steve Wozniak

 1977 - The Bourne Shell Developed by Stephen Bourne

 1978 - The C Shell Developed by Bill Joy

 1978 - Bash (Bourne-Again Shell) Developed by Brian Fox

 1979 - The Tcsh (TENEX C Shell) Developed by Ken Greer

 1983 - "Sendmail" Mail Transfer Agent Developed by Eric Allman

 1984 - Macintosh Developed by Apple Inc.

 1984 - X Window System Developed a MIT Team

 1991 - WWW (World Wide Web) Developed by Tim Berners-Lee

 1991 - Gopher Protocol Created by a University of Minnesota Team

 1995 - Java Language Developed by Sun Microsystems

 1995 - PHP: Hypertext Preprocessor Created by Rasmus Lerdorf

 2002 - .NET Framework Developed by Microsoft

 References

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