[Perl-beginners] Doubt

On Wed, 14 May 2003, Helder Gomes da Silva wrote:

Hi everybody...
Supose that i have a file that i have to use many times.
But, in that file is a line that changes everytime that i have
to use the file.
I know the number of that line.
May I only overwrite that line everytime I need the file or
I am obligated, like i'm doing now, to write the entire file
of each time i have to use it.

This is the file that i have to write

==============================================================

1 global env tcl_platform
2 source "$env(ASCENDTK)/ascend.tcl"
3 READ FILE "~/ascdata/heat_recover/heat_recover.a4c";
4 COMPILE hr OF heat_recover;
5 RUN {hr.reset};
6 RUN {hr.values};
7 ASSIGN {hr.T2} 150 {Kelvin};
8 SOLVE {hr} WITH QRSlv;
9 WRITE VALUES {hr.FOB}
"heat_recover/results/FOB_heat_recover150.dat";
10 exit;

==============================================================

And, at everytime I use it, the only change is the value 150 at line 7.

Can someone give me a tip?

Thank you very much!!

--
Helder Gomes da Silva

e-mail: hgsilva@fe.up.pt
URL: http://www.fe.up.pt/~hgsilva



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George P. wrote:
On Wed, 14 May 2003, Helder Gomes da Silva wrote:

I'm not sure what you want to do.. but, if you have to use the file
contents many times in one program, you could push the entire file
into an array. This way, you can also change any line you want.

my (@lns);
open(F1, "< $file") or die("ERROR: Cannot open $file: $!\n");
@lns = <>;
close F1;

$lns[6] =~ s/} \d+ {/} 100 {/;
## Above I'm changing all digits between "} " and " {"
## to 100 on the 7th line.

-George P.

Helder Gomes Da Silva wrote:
Hi everybody...
Supose that i have a file that i have to use many times.
But, in that file is a line that changes everytime that i have
to use the file.
I know the number of that line.
May I only overwrite that line everytime I need the file or
I am obligated, like i'm doing now, to write the entire file
of each time i have to use it.

This is the file that i have to write

==============================================================

1 global env tcl_platform
2 source "$env(ASCENDTK)/ascend.tcl"
3 READ FILE "~/ascdata/heat_recover/heat_recover.a4c";
4 COMPILE hr OF heat_recover;
5 RUN {hr.reset};
6 RUN {hr.values};
7 ASSIGN {hr.T2} 150 {Kelvin};
8 SOLVE {hr} WITH QRSlv;
9 WRITE VALUES {hr.FOB} "heat_recover/results/FOB_heat_recover150.dat";
10 exit;

==============================================================

And, at everytime I use it, the only change is the value 150 at line 7.

Can someone give me a tip?