[SOLVED] Fortran How to open a file in loop?

parekhharsh_j · 06-29-2011, 11:09 AM

I have a 50 file name NSSAVE0001.vtk to NSSAVE0050.vtk.
Do I have to manually type individually command to open each file or can I have a loop to open file?

smallpond · 06-29-2011, 11:46 AM

Quote:

Originally Posted by parekhharsh_j

I have a 50 file name NSSAVE0001.vtk to NSSAVE0050.vtk.
Do I have to manually type individually command to open each file or can I have a loop to open file?

Pretty sure the file name can be in an array, so no reason not to use the loop.

parekhharsh_j · 06-29-2011, 11:51 AM

Quote:

Originally Posted by smallpond

Pretty sure the file name can be in an array, so no reason not to use the loop.

If it is possible then how?
How to write file name?

Code:

do n=1,50
nn=n+10
open(unit=nn,file=??)
enddo

makyo · 06-29-2011, 03:37 PM

Hi.

Here is a driver for a sample Fortran code to create filenames as strings:

Code:

#!/usr/bin/env bash

# @(#) s1	Demonstrate creating of file names as character strings.

# Utility functions: print-as-echo, print-line-with-visual-space, debug.
# export PATH="/usr/local/bin:/usr/bin:/bin"
pe() { for _i;do printf "%s" "$_i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
db() { ( printf " db, ";for _i;do printf "%s" "$_i";done;printf "\n" ) >&2 ; }
db() { : ; }
C=$HOME/bin/context && [ -f $C ] && $C gfortran

FILE=${1-one.f90}
rm -f a.out nssave*

pl " Fortran source:"
cat $FILE

pl " Compile, link, execute:"
gfortran $FILE
./a.out

pl " Resultant files opened (created):"
ls -lgG nssave*

producing:

Code:

% ./s1

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Linux, 2.6.26-2-amd64, x86_64
Distribution        : Debian GNU/Linux 5.0.8 (lenny) 
GNU bash 3.2.39
gfortran GNU Fortran (Debian 4.3.2-1.1) 4.3.2

-----
 Fortran source:
     program f1

       character*20 :: my_unit

       do n=1,5
         write(my_unit,"(a,i4.4,a)") "nssave",n,".vtk"
         write(*,*) " Preparing to open file: ",my_unit
         open(unit=1,file=my_unit,err=100)
       end do
       stop "f1"

100    continue
       write(*,*) " Error in opening file: ", my_unit

     end

-----
 Compile, link, execute:
  Preparing to open file: nssave0001.vtk      
  Preparing to open file: nssave0002.vtk      
  Preparing to open file: nssave0003.vtk      
  Preparing to open file: nssave0004.vtk      
  Preparing to open file: nssave0005.vtk      
STOP f1

-----
 Resultant files opened (created):
-rw-r--r-- 1 0 Jun 29 15:35 nssave0001.vtk
-rw-r--r-- 1 0 Jun 29 15:35 nssave0002.vtk
-rw-r--r-- 1 0 Jun 29 15:35 nssave0003.vtk
-rw-r--r-- 1 0 Jun 29 15:35 nssave0004.vtk
-rw-r--r-- 1 0 Jun 29 15:35 nssave0005.vtk

Good luck ... cheers, makyo