[SOLVED] To skip lines from the beginning of a file using FORTRAN commands

saj · 05-26-2011, 02:11 AM

Using
READ (8, FMT= '(A1)') dummy
READ (8, FMT= '(A2)') dummy
READ (8, FMT= '(A3)') dummy etc. [8 - file that is being read]
it is possible to skip header lines of a selected input file.

However, I need to skip 95 header lines (1 to 95) and using the above method is not a very practical idea because I need to go on till (A95).

My question is, would there be a shorter way to do the same thing?

Thank you and all help is appreciated.

makyo · 05-28-2011, 04:48 PM

Hi.

This seems to work. The driver script posts the data file and source code, then compiles and executes:

Code:

#!/usr/bin/env bash

# @(#) s1	Demonstrate compile and execute F-90 code.

# Utility functions: print-as-echo, print-line-with-visual-space, debug.
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-data1}

pl " Input data file $FILE:"
cat $FILE

pl " Fortran source:"
cat one.f90

pl " Results for skipping headers:"
rm -f a.out
gfortran -Wall --free-form one.f90
./a.out

exit 0

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

-----
 Input data file data1:
a
b
c
d This is a long line
e
f
g
h
i
j

-----
 Fortran source:
     program f1

! @(#) f1	Demonstrate Fortran-90.

       character*1 dummy
       character*80 line

       integer :: i, limit
       data i, limit / 1, 5 /

       open(8,file="data1")

       do
         if ( i > limit ) exit
         read(8,'(a1)') dummy
         write(*,*) " Iteration ",i," line skipped ",dummy
         i = i + 1
       end do

       read(8,'(a)') line
       write(*,*) " Line after skip is ", line

       stop "f1"
     end

-----
 Results for skipping headers:
  Iteration            1  line skipped a
  Iteration            2  line skipped b
  Iteration            3  line skipped c
  Iteration            4  line skipped d
  Iteration            5  line skipped e
  Line after skip is f  
                                                                             
STOP f1

Best wishes ... cheers, makyo

saj · 05-31-2011, 11:51 PM

Thank you makyo.

It works fine and I only have to put the number of lines I need to skip as; DATA I, limit /1, 97/

Quote:

Originally Posted by makyo

Hi.

This seems to work. The driver script posts the data file and source code, then compiles and executes:

Code:

#!/usr/bin/env bash

# @(#) s1	Demonstrate compile and execute F-90 code.

# Utility functions: print-as-echo, print-line-with-visual-space, debug.
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-data1}

pl " Input data file $FILE:"
cat $FILE

pl " Fortran source:"
cat one.f90

pl " Results for skipping headers:"
rm -f a.out
gfortran -Wall --free-form one.f90
./a.out

exit 0

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

-----
 Input data file data1:
a
b
c
d This is a long line
e
f
g
h
i
j

-----
 Fortran source:
     program f1

! @(#) f1	Demonstrate Fortran-90.

       character*1 dummy
       character*80 line

       integer :: i, limit
       data i, limit / 1, 5 /

       open(8,file="data1")

       do
         if ( i > limit ) exit
         read(8,'(a1)') dummy
         write(*,*) " Iteration ",i," line skipped ",dummy
         i = i + 1
       end do

       read(8,'(a)') line
       write(*,*) " Line after skip is ", line

       stop "f1"
     end

-----
 Results for skipping headers:
  Iteration            1  line skipped a
  Iteration            2  line skipped b
  Iteration            3  line skipped c
  Iteration            4  line skipped d
  Iteration            5  line skipped e
  Line after skip is f  
                                                                             
STOP f1

Best wishes ... cheers, makyo