Re: How to call a C function from D that takes a FILE * as an argument?
On Wednesday, 4 July 2018 at 02:54:47 UTC, Joe wrote:
On Wednesday, 4 July 2018 at 02:16:00 UTC, Seb wrote:
Hmm, calling e.g. fprintf with stdout should just work:
---
void main()
{
import core.stdc.stdio;
fprintf(stdout, "Hello %s", "world".ptr);
}
---
Could you maybe provide your whole code?
This short test program shows the error:
---
import std.stdio;
void main()
{
extern (C) void list(FILE *fd);
list(stdout);
}
---
Now I fixed this by changing the import to core.stdc.stdio. I
guess the problem is if you import std.stdio (which brings in
the other one), there are two slightly incompatible stdout's
and the D takes precedence.
`stdout.getFP` (stdout is of the D std.stdio.File struct type and
with getFP you get the underlying FILE*)
Re: How to call a C function from D that takes a FILE * as an argument?
On Wednesday, 4 July 2018 at 02:54:47 UTC, Joe wrote: Now I fixed this by changing the import to core.stdc.stdio. I guess the problem is if you import std.stdio (which brings in the other one), there are two slightly incompatible stdout's and the D takes precedence. If you import both modules (or even I think if just the D std.stdio, since it publicly imports the other), you can specify the C one by using its full name: core.stdc.stdio.stdout where you use it. of course you can also alias it to something shorter.
Re: How to call a C function from D that takes a FILE * as an argument?
On Wednesday, 4 July 2018 at 02:16:00 UTC, Seb wrote:
Hmm, calling e.g. fprintf with stdout should just work:
---
void main()
{
import core.stdc.stdio;
fprintf(stdout, "Hello %s", "world".ptr);
}
---
Could you maybe provide your whole code?
This short test program shows the error:
---
import std.stdio;
void main()
{
extern (C) void list(FILE *fd);
list(stdout);
}
---
Now I fixed this by changing the import to core.stdc.stdio. I
guess the problem is if you import std.stdio (which brings in the
other one), there are two slightly incompatible stdout's and the
D takes precedence.
Re: How to call a C function from D that takes a FILE * as an argument?
On Wednesday, 4 July 2018 at 02:08:11 UTC, Joe wrote:
On Wednesday, 4 July 2018 at 01:58:15 UTC, Seb wrote:
So just add the declaration to your D file:
---
extern(C) void myCfunction(FILE* stream);
---
I do have a similar declaration in D. It appears the problem
is that the C program I'm trying to convert passes stdout as
the argument and the D compiler complains somewhat like the
following:
Error: function foo.main.myCfunction (shared(_IO_FILE)* stream)
is not callable using argument types (File)
So I guess the question is what to pass instead of stdout.
Hmm, calling e.g. fprintf with stdout should just work:
---
void main()
{
import core.stdc.stdio;
fprintf(stdout, "Hello %s", "world".ptr);
}
---
Could you maybe provide your whole code?
Re: How to call a C function from D that takes a FILE * as an argument?
On Wednesday, 4 July 2018 at 01:58:15 UTC, Seb wrote: So just add the declaration to your D file: --- extern(C) void myCfunction(FILE* stream); --- I do have a similar declaration in D. It appears the problem is that the C program I'm trying to convert passes stdout as the argument and the D compiler complains somewhat like the following: Error: function foo.main.myCfunction (shared(_IO_FILE)* stream) is not callable using argument types (File) So I guess the question is what to pass instead of stdout.
Re: How to call a C function from D that takes a FILE * as an argument?
On Wednesday, 4 July 2018 at 01:06:36 UTC, Joe wrote:
The subject basically says it all. The C function uses the
argument to call fprintf and also passes it to other functions
where it's used to call fileno, fprintf or putc.
Like you would with C's fprintf
(https://dlang.org/phobos/core_stdc_stdio.html#.fprintf).
For example, this is a valid D program:
---
void main(string[] args)
{
import core.stdc.stdio;
FILE* pFile;
int n;
char[100] name;
pFile = fopen ("myfile.txt","w"); // string literals are
zero-terminated
for (n=0 ; n<3 ; n++)
{
puts("please, enter a name: ");
gets(name.ptr);
fprintf pFile, "Name %d [%-10.10s]\n",n+1,name.ptr);
}
fclose(pFile);
}
---
(example from http://www.cplusplus.com/reference/cstdio/fprintf)
So just add the declaration to your D file:
---
extern(C) void myCfunction(FILE* stream);
---
and as long as you link your program into the D binary, you
should be good to go.
For larger C bases, tools like dstep or dpp can help translating
C/C++ header files to D.
How to call a C function from D that takes a FILE * as an argument?
The subject basically says it all. The C function uses the argument to call fprintf and also passes it to other functions where it's used to call fileno, fprintf or putc.
