Fortran compiler on suse11

vovo · 01-28-2009, 03:39 PM

hi

i am new to linux......i installed fortran77 using Yast and it indicates that its installed.when i check the respositories..i dont see the gcc fort4.3...am i supposed to see it? also where do i get the manual for beginners to start with fortran compilers.

thanks

colucix · 01-28-2009, 04:02 PM

Which package did you install exactly? If using the search form in Yast and type "fortran" you end up with gcc43-fortran, which provides the gfortran compiler. To start using it, just write a simple code and try it out:

Code:

gfortran code.f90

If you are looking for a very basic introduction to Fortran, I can suggest this guide from ITS at University of Durham. Feel free to ask if you encounter any problem. Programming questions have to be posted in the Programming forum for a better visibility.

vovo · 01-29-2009, 02:24 AM

i have installed SUSE10.2

you are right Yast I get gcc43-fortran.

About the code...i tried it on the terminal , but it says "no such file or diretotry"

Thanks for the fortran guide

colucix · 01-29-2009, 03:35 AM

Quote:

Originally Posted by vovo

About the code...i tried it on the terminal , but it says "no such file or diretotry"

Of course. Mine was just an example of a dummy command line. If you want to test it out put the following code in a file named code.f90:

Code:

PROGRAM hello
  IMPLICIT NONE
  CHARACTER(LEN=12):: string = 'Hello vovo!'
  WRITE(*,*) string
  string = 'How are you?'
  WRITE(*,*) string
END PROGRAM hello

then from the directory where the file is saved, do the following two commands:

Code:

# gfortran code.f90
# ./a.out

Congratulations, you did run your first Fortran program!

Just out of curiosity: you stated in the OP that you run on opensuse 11... why have you downgraded to 10.2?

vovo · 02-03-2009, 07:21 AM

i made amistake....its suse11.0

colucix · 02-03-2009, 07:23 AM

Ok. Have you tried the simple example I posted? Does it work?

vovo · 02-04-2009, 03:38 PM

yeap.....but i could not run it.I believe, i have to make it a textfile first....then save it as a textfile.Now when i do ls.....i can see it but when i try to run it .using gfortran code.90...its says :

/usr/lib/gcc/i586-suse-linux/4.3/../../../../i586-suse-linux/bin/ld:code.90: file format not recognized; treating as linker script
/usr/lib/gcc/i586-suse-linux/4.3/../../../../i586-suse-linux/bin/ld:code.90:1: syntax error
collect2: ld returned 1 exit status

by the way i used vim .......newfile in the terminal.On emacs i saved it as test22.
Does it have to be on a directory

colucix · 02-04-2009, 11:26 PM

Code:

code.90: file format not recognized

This is because fortran compilers in general are very picky about the file names. They have a bunch of extensions which recognize as fortran programs, the other are discarded. In short, just change the extension to .f90 and the trick is done!

vovo · 02-07-2009, 02:32 PM

i am trying formating......for integers, its refusing me to use e.g.i3
At line 10 of file money.f90 (unit = 5, file = 'stdin')
Fortran runtime error: Expected INTEGER for item 2 in formatted transfer, gotCHARACTER
(2x,i3,a4,f6.2)
^

Thanks

vovo · 02-07-2009, 02:46 PM

what is the right syntax to use for an output filename...instead of out.dat....to see only the output file not the contents on the screen.
Thanks

colucix · 02-07-2009, 03:21 PM

Quote:

Originally Posted by vovo

At line 10 of file money.f90 (unit = 5, file = 'stdin')
Fortran runtime error: Expected INTEGER for item 2 in formatted transfer, gotCHARACTER
(2x,i3,a4,f6.2)

This means that in the read/write statement where you use the format (2x,i3,a4,f6.2) you put a character as the first argument in place of the expected integer. For example:

Code:

      write(*,10) 'c','fg',78.4
  10  format(2x,i3,a4,f6.2)

the write statement above tries to put a 'c' whereas it expects an integer number because of the format specification.

colucix · 02-07-2009, 03:23 PM

Quote:

Originally Posted by vovo

what is the right syntax to use for an output filename...instead of out.dat....to see only the output file not the contents on the screen.
Thanks

Sorry... I don't understand this question. Where out.dat comes from? Please, post the code you're talking about, otherwise it's difficult for us to guess how it is and where the problem comes from. Thanks.

vovo · 02-09-2009, 03:47 PM

the program is supposed to write the output ONLY TO A FILE not on the screen, so i am supposed to use:
open(1,file='out.dat').......
by the way....i have been using ./a.out to run my output,so if i wanna name my outputfile so that i dont get confused, but i can see all my outputs as files, what do i use......i want my output to have the same filename as the program.....
Thanks

lauer · 02-10-2009, 04:46 AM

Is this a fortran progamming course

colucix · 02-10-2009, 09:39 AM

When you open a file for writing, chose a unit at least greater than 6 or even better a two-digit unit number. The first six units are reserved to some default I/O devices, for example unit 5 is standard input (the terminal) and unit 6 is standard output (the terminal). So use for example

Code:

open(11, file='out.dat')

If you want to determine automatically the name of the output file, based on the name of the executable, you have first to read it using the getarg() function and retrieving argument 0. For example

Code:

PROGRAM test
IMPLICIT NONE
CHARACTER(len=20):: string0
CHARACTER(len=25):: string1
CALL GETARG(0,string0)
string1 = TRIM(string0)//'.dat'
OPEN(11,file=string1)
WRITE(11,*) 'write something now'
CLOSE(11)
END PROGRAM test

this will create an output file called test.dat provided the executable file is simply called test.

Finally to give a name different than a.out to the executable file, you can just rename it at your pleasure or use the -o option to specify it during the compilation.