Kindly tell the pseudocode to solve the following
problem:
An user input is provided to a perl program by
STDIN. This input is utilised by a fortran program to
perform some function. How do i connect both the
programs & get the output from the fortran program to
the user via the perl program itself.
Waiting for an early response. thanking you...
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On Wed, 6 Jul 2005, madhurima das wrote:
| QUOTE |
| Kindly tell the pseudocode to solve the following problem: An user input is provided to a perl program by STDIN. This input is utilised by a fortran program to perform some function. How do i connect both the programs & get the output from the fortran program to the user via the perl program itself. Waiting for an early response. thanking you... |
Here's some pseudocode:
$response = get_user_input();
$result = have_fortran_work_on( $response );
$finish = tell_user_about( $result );
# maybe or maybe not do anything with $finish
For the Fortran bit I've stubbed into have_fortran_work_on(), the usual
way to do this, short of an Inline::Fortran module on CPAN (there
doesn't seem to be one, though there are ones like Inline::C, etc), is
to make a system() call to the external program.
<http://perldoc.perl.org/functions/system.html>
Try using a system() call in your own pseudocode for
have_fortran_work_on().
If you're stuck, ask more specific questions, and show what you've tried
so far.
--
Chris Devers
madhurima das <[Email Removed]> asked:
| QUOTE |
| An user input is provided to a perl program by STDIN. This input is utilised by a fortran program to perform some function. How do i connect both the programs & get the output from the fortran program to the user via the perl program itself. Waiting for an early response. thanking you... |
The section "Bidirectional Communication with Another Process"
in the perlipc manpage ("perldoc perlipc") should tell you all
you need to know (and then some ;-)).
HTH,
Thomas
On 7/6/05, Chris Devers <[Email Removed]> wrote:
| QUOTE |
| On Wed, 6 Jul 2005, madhurima das wrote: Kindly tell the pseudocode to solve the following problem: An user input is provided to a perl program by STDIN. This input is utilised by a fortran program to perform some function. How do i connect both the programs & get the output from the fortran program to the user via the perl program itself. Waiting for an early response. thanking you... Here's some pseudocode: $response = get_user_input(); $result = have_fortran_work_on( $response ); $finish = tell_user_about( $result ); # maybe or maybe not do anything with $finish For the Fortran bit I've stubbed into have_fortran_work_on(), the usual way to do this, short of an Inline::Fortran module on CPAN (there doesn't seem to be one, though there are ones like Inline::C, etc), is to make a system() call to the external program. <http://perldoc.perl.org/functions/system.html Try using a system() call in your own pseudocode for have_fortran_work_on(). If you're stuck, ask more specific questions, and show what you've tried so far. -- Chris Devers |
system() probably won't do what you want: it's value it the return
value of the wait system call, not the output of the external program.
If you want to capture the output directly (as opposed to, say,
writing to a file and then parsing the file in Perl) you'll want to
use backticks or qx//. See 'perldoc -f system' or '`STRING`' or
'qx/STRING/' in perlop for more info.
HTH
-- jay
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Thanks for the reply sir. But i am still stuck with
the same old problem since the system() function isn't
working & the manpages aren't of much help either.
Giving below an account of what my programs are &
their output:
####PERL PROGRAM####
#assign.pl#
#!/usr/bin/perl
use strict;
use warnings;
print "enter the first numbern";
my $x = <STDIN>;
chomp $x;
print "enter the second numbern";
my $y = <STDIN>;
chomp $y;
my $z = system("assign.f",'$x','$y');
print "Output of the two numbers is:n";
print $z,"n";
exit;
#output#
the same old problem since the system() function isn't
working & the manpages aren't of much help either.
Giving below an account of what my programs are &
their output:
####PERL PROGRAM####
#assign.pl#
#!/usr/bin/perl
use strict;
use warnings;
print "enter the first numbern";
my $x = <STDIN>;
chomp $x;
print "enter the second numbern";
my $y = <STDIN>;
chomp $y;
my $z = system("assign.f",'$x','$y');
print "Output of the two numbers is:n";
print $z,"n";
exit;
#output#
| QUOTE |
| $perl assign.pl enter the first number |
2
enter the second number
4
Can't exec "assign.f": Permission denied at assign
line 10, <STDIN> line 2.
Output of the two numbers is:
-1
#####FORTRAN PROGRAM#####
c assign.f
WRITE(*,*) "ENTER FIRST NUMBER"
READ(*,*) x
WRITE(*,*) "ENTER SECOND NUMBER"
READ(*,*) y
z = x+y
WRITE(*,*)z
END
#output#
| QUOTE |
| $g77 assign.f $ ./a.out ENTER FIRST NUMBER |
2
ENTER SECOND NUMBER
4
OUTPUT OF THE TWO NUMBERS IS:
6.
Can you suggest sir what should be my approach to this
problem. Waiting for an early response from you.
Thanking you..
_______________________________________________________
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Thanks for the reply sir. But i am still stuck with
the same old problem since the system() function isn't
working & the manpages aren't of much help either.
Giving below an account of what my programs are &
their output:
####PERL PROGRAM####
#assign.pl#
#!/usr/bin/perl
use strict;
use warnings;
print "enter the first numbern";
my $x = <STDIN>;
chomp $x;
print "enter the second numbern";
my $y = <STDIN>;
chomp $y;
my $z = system("assign.f",'$x','$y');
print "Output of the two numbers is:n";
print $z,"n";
exit;
#output#
the same old problem since the system() function isn't
working & the manpages aren't of much help either.
Giving below an account of what my programs are &
their output:
####PERL PROGRAM####
#assign.pl#
#!/usr/bin/perl
use strict;
use warnings;
print "enter the first numbern";
my $x = <STDIN>;
chomp $x;
print "enter the second numbern";
my $y = <STDIN>;
chomp $y;
my $z = system("assign.f",'$x','$y');
print "Output of the two numbers is:n";
print $z,"n";
exit;
#output#
| QUOTE |
| $perl assign.pl enter the first number |
2
enter the second number
4
Can't exec "assign.f": Permission denied at assign
line 10, <STDIN> line 2.
Output of the two numbers is:
-1
#####FORTRAN PROGRAM#####
c assign.f
WRITE(*,*) "ENTER FIRST NUMBER"
READ(*,*) x
WRITE(*,*) "ENTER SECOND NUMBER"
READ(*,*) y
z = x+y
WRITE(*,*)z
END
#output#
| QUOTE |
| $g77 assign.f $ ./a.out ENTER FIRST NUMBER |
2
ENTER SECOND NUMBER
4
OUTPUT OF THE TWO NUMBERS IS:
6.
Can you suggest sir what should be my approach to this
problem. Waiting for an early response from you.
Thanking you..
__________________________________________________________
How much free photo storage do you get? Store your friends 'n family snaps for FREE with Yahoo! Photos http://in.photos.yahoo.com
Thanks for the reply sir. But i am still stuck with
the same old problem since the system() function isn't
working & the manpages aren't of much help either.
Giving below an account of what my programs are &
their output:
####PERL PROGRAM####
#assign.pl#
#!/usr/bin/perl
use strict;
use warnings;
print "enter the first numbern";
my $x = <STDIN>;
chomp $x;
print "enter the second numbern";
my $y = <STDIN>;
chomp $y;
my $z = system("assign.f",'$x','$y');
print "Output of the two numbers is:n";
print $z,"n";
exit;
#output#
the same old problem since the system() function isn't
working & the manpages aren't of much help either.
Giving below an account of what my programs are &
their output:
####PERL PROGRAM####
#assign.pl#
#!/usr/bin/perl
use strict;
use warnings;
print "enter the first numbern";
my $x = <STDIN>;
chomp $x;
print "enter the second numbern";
my $y = <STDIN>;
chomp $y;
my $z = system("assign.f",'$x','$y');
print "Output of the two numbers is:n";
print $z,"n";
exit;
#output#
| QUOTE |
| $perl assign.pl enter the first number |
2
enter the second number
4
Can't exec "assign.f": Permission denied at assign
line 10, <STDIN> line 2.
Output of the two numbers is:
-1
#####FORTRAN PROGRAM#####
c assign.f
WRITE(*,*) "ENTER FIRST NUMBER"
READ(*,*) x
WRITE(*,*) "ENTER SECOND NUMBER"
READ(*,*) y
z = x+y
WRITE(*,*)z
END
#output#
| QUOTE |
| $g77 assign.f $ ./a.out ENTER FIRST NUMBER |
2
ENTER SECOND NUMBER
4
OUTPUT OF THE TWO NUMBERS IS:
6.
Can you suggest sir what should be my approach to this
problem. Waiting for an early response from you.
Thanking you..
__________________________________________________________
How much free photo storage do you get? Store your friends 'n family snaps for FREE with Yahoo! Photos http://in.photos.yahoo.com
madhurima das <[Email Removed]> asked:
| QUOTE |
| Thanks for the reply sir. But i am still stuck with the same old problem since the system() function isn't working & the manpages aren't of much help either. |
system() won't work the way you want to use it. From the manpage:
"The return value is the exit status of the program as returned
by the wait call."
Passing the arguments the way you do also doesn't work because
your Fortran code expects to read them from standard input.
This looks like a job for open2 or the expect module.
HTH,
Thomas
On Jul 7, madhurima das said:
| QUOTE |
| #assign.pl# #!/usr/bin/perl use strict; use warnings; print "enter the first numbern"; my $x = <STDIN>; chomp $x; print "enter the second numbern"; my $y = <STDIN>; chomp $y; my $z = system("assign.f",'$x','$y'); |
Many things wrong here:
1. system() does NOT return the OUTPUT of the program it runs (see the
docs: perldoc -f system)
2. you have single quoted $x and $y, which means they are simply the
strings $x and $y -- you wanted Perl's values for those variables
3. you're calling assign.f, instead of a.out
4. assign.f reads its values from STDIN, not from the commandline
Assuming you have compiled assign.f to a.out, I would do the following:
use IPC::Open2;
open2 my($read), my($write), "./a.out"
or die "can't open2 ./a.out: $!";
<$read>; # read (and discard) a line of output
print $write "$xn";
<$read>; # read (and discard) the next line of output
print $write "$yn";
chomp(my $z = <$read>); # read (and save) the next line of output
close $read;
close $write;
--
Jeff "japhy" Pinyan % How can we ever be the sold short or
RPI Acacia Brother #734 % the cheated, we who for every service
http://japhy.perlmonk.org/ % have long ago been overpaid?
http://www.perlmonks.org/ % -- Meister Eckhart
Can you try with backtick or qx[ ] ?
my $z = `assign.f $x $y`;
hth.
my $z = `assign.f $x $y`;
hth.
| QUOTE |
| Can't exec "assign.f": Permission denied at assign line 10, <STDIN> line 2. Output of the two numbers is: -1 |
--Muthu
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