Hi,

I have a hard time reading in a string from a file. I don't get any compile time or run time errors, but my application does not work reliably when I read a string from a file. But when I define the same string within my code, everything runs perfect, allways.
The string I want to use is an OpenGL Shader, but the problem is not to be related to OpenGL as far as a I see.
Are there some format strings which I need to get rid of, and how ?

I tried:
import std.file ;
string fragString = readText( "Shader.vert" ) ;

import std.file , std.utf ;
string fragString = toUTF8( readText( "Shader.vert" ) ) ;

import std.stdio ;
string text = "" ;
auto file = File( "Shader.vert" ) ;
foreach( line ; file.byLine() )  string ~= strip( to!( string )( line ) ) ;

What else could I try ?

Cheers, ParticlePeter !

On 12/12/2011 03:35 PM, ParticlePeter wrote:
> Hi,
>
> I have a hard time reading in a string from a file. I don't get any compile time or run time errors, but my application does not work reliably when I read a string from a file. But when I define the same string within my code, everything runs perfect, allways.
> The string I want to use is an OpenGL Shader, but the problem is not to be related to OpenGL as far as a I see.
> Are there some format strings which I need to get rid of, and how ?
>
> I tried:
> import std.file ;
> string fragString = readText( "Shader.vert" ) ;
>
> import std.file , std.utf ;
> string fragString = toUTF8( readText( "Shader.vert" ) ) ;
>
> import std.stdio ;
> string text = "" ;
> auto file = File( "Shader.vert" ) ;
> foreach( line ; file.byLine() )  string ~= strip( to!( string )( line ) ) ;
>
> What else could I try ?
>
> Cheers, ParticlePeter !
>

OpenGL probably wants a zero-terminated string. It works if you add the code as a literal because string literals are zero-terminated.

string fragString = readText( "Shader.vert" ) ~ '\0';

Alternatively, you can embed the file in you executable:

immutable string fragString = import( "Shader.vert" ); // read at compile time

Timon Gehr:

> string fragString = readText( "Shader.vert" ) ~ '\0';

I think using toStringz is more self-documenting.

Bye,
bearophile

On 12/12/2011 06:37 PM, bearophile wrote:
> Timon Gehr:
>
>> string fragString = readText( "Shader.vert" ) ~ '\0';
>
> I think using toStringz is more self-documenting.
>
> Bye,
> bearophile

There is nothing more self-documenting than actually appending the zero. Claiming toStringz is better in that regard is like saying a+1 is less self-documenting than doAddo(a) ;)
There might be other benefits of using toStringz though, (for example, it won't add the zero if it is already there, but that does not apply here).

On Mon, 12 Dec 2011 12:59:11 -0500, Timon Gehr <timon.gehr@gmx.ch> wrote:

> On 12/12/2011 06:37 PM, bearophile wrote:
>> Timon Gehr:
>>
>>> string fragString = readText( "Shader.vert" ) ~ '\0';
>>
>> I think using toStringz is more self-documenting.
>>
>> Bye,
>> bearophile
>
> There is nothing more self-documenting than actually appending the zero. Claiming toStringz is better in that regard is like saying a+1 is less self-documenting than doAddo(a) ;)
> There might be other benefits of using toStringz though, (for example, it won't add the zero if it is already there, but that does not apply here).

x ~ y *always* makes a copy of x, whereas toStringz(x) will (should?) use append (which could potentially save another heap allocation).  However, I'm not sure what kind of state the result of readText is in.

-Steve

Thank you very much, you made my day, that was it :-)

Cheers, ParticlePeter !

> OpenGL probably wants a zero-terminated string. It works if you add the code as a literal because string literals are zero-terminated.
> 
> string fragString = readText( "Shader.vert" ) ~ '\0';
> 
> Alternatively, you can embed the file in you executable:
> 
> immutable string fragString = import( "Shader.vert" ); // read at compile time