I am trying to read lines from stdin and echo them to stdout.

I have come up with this:

import std.stdio;
import std.cstream;
import std.string;

void main () {
    while (!din.eof()) {
        char[] line = din.readLine();
        if (line == null) continue;
        writefln("%s", line);
    }
}

but am confused why I would need to check for null.  Is there a better way to do this?


Bill
-- 
r * e * @ * o * y * a * c * m
* a * l * z * p * r * . * o *

"Bill Lear" <rael@see.sig.com> wrote in message news:m33b621rvp.fsf@pppp.zopyra.com...
>I am trying to read lines from stdin and echo them to stdout.
>
> I have come up with this:
>
> import std.stdio;
> import std.cstream;
> import std.string;
>
> void main () {
>    while (!din.eof()) {
>        char[] line = din.readLine();
>        if (line == null) continue;
>        writefln("%s", line);
>    }
> }
>
> but am confused why I would need to check for null.  Is there a better way to do this?

Do you?  I took out the null check and it works fine, unless you're getting errors on Linux or something.

"Jarrett Billingsley" <kb3ctd2@yahoo.com> writes:
> "Bill Lear" <rael@see.sig.com> wrote in message news:m33b621rvp.fsf@pppp.zopyra.com...
> >I am trying to read lines from stdin and echo them to stdout.
> >
> > I have come up with this:
> >
> > import std.stdio;
> > import std.cstream;
> > import std.string;
> >
> > void main () {
> >    while (!din.eof()) {
> >        char[] line = din.readLine();
> >        if (line == null) continue;
> >        writefln("%s", line);
> >    }
> > }
> >
> > but am confused why I would need to check for null.  Is there a better way to do this?
> 
> Do you?  I took out the null check and it works fine, unless you're getting errors on Linux or something.

Yes, this is under Linux, dmd version 1.00.  If I run the program, with the text of the program as input, without the null check, it prints out an additional blank line for every line in the file.


Bill
-- 
r a e l @
z o p y r a .
c o m

"Bill Lear" <rael@see.sig.com> wrote in message news:m3hcuhzkpe.fsf@lisa.zopyra.com...

> Yes, this is under Linux, dmd version 1.00.  If I run the program, with the text of the program as input, without the null check, it prints out an additional blank line for every line in the file.

Hmm, that doesn't happen under Windows.  I guess it's a platform-specific issue.  Might want to post it in Bugzilla (I can't find any issues about it there already).

Jarrett Billingsley schrieb am 2007-01-24:
> "Bill Lear" <rael@see.sig.com> wrote in message news:m3hcuhzkpe.fsf@lisa.zopyra.com...
>
>> Yes, this is under Linux, dmd version 1.00.  If I run the program, with the text of the program as input, without the null check, it prints out an additional blank line for every line in the file.
>
> Hmm, that doesn't happen under Windows.  I guess it's a platform-specific issue.  Might want to post it in Bugzilla (I can't find any issues about it there already).

http://d.puremagic.com/issues/show_bug.cgi?id=881

Thomas