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Help in passing the path to a C function - URGENT
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Uma Veerama
#1 / 5
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 Help in passing the path to a C function - URGENT Hi All,
I have a requirement to pass the path along with the filename to a
function to perform some read operations. I might use this function(as
library) in Visual Basic as well as any C/C++ program.The function
definition goes like this :
int ReadContent(char *filename);
This function reads the contents of the file name which I pass as the
parameter.
This function is called like this :
int result;
result = ReadContent("C:\\New\\Readme.txt");
In VB, the programmer might give the path name as "C:\New\Readme.txt"
and the function call will not work. I don't have any control over the
client program and this function resides in a library. So, can I do
something in the library program by which I can replace the single
back slash with double slash ? Is it possible or not ?
Thanks in advance.
Regards
Uma
PS: If I pass a string with a single back slash in it, it is actually
omitted and it comes into the library as c:NewReadme.txt , so even if
I want to replace the single backslash character with 2 backslash
characters, I am not able to do that in the library where the function
resides.
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| Tue, 18 May 2004 05:33:14 GMT |
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Gordon Burdi
#2 / 5
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Help in passing the path to a C function - URGENT Quote: >Hi All, > I have a requirement to pass the path along with the filename to a >function to perform some read operations. I might use this function(as >library) in Visual Basic as well as any C/C++ program.The function >definition goes like this : >int ReadContent(char *filename);
>This function reads the contents of the file name which I pass as the
>parameter.
>This function is called like this :
>int result;
>result = ReadContent("C:\\New\\Readme.txt");
to the function. You need the double backslashes BECAUSE THIS TEXT
IS IN A QUOTED STRING CONSTANT, not because you are passing a string.
Quote: >In VB, the programmer might give the path name as "C:\New\Readme.txt"
>and the function call will not work.
If you pass that value NOT AS A QUOTED STRING CONSTANT but as
a character array into which you have read user input, it should
work fine.
Quote: >I don't have any control over the
>client program and this function resides in a library. So, can I do
>something in the library program by which I can replace the single
>back slash with double slash ? Is it possible or not ?
If you are passing a character array into which you have read
user input, you don't need to do this.
Quote: >Thanks in advance.
>Regards
>Uma
>PS: If I pass a string with a single back slash in it, it is actually
>omitted and it comes into the library as c:NewReadme.txt , so even if
it is actually omitted and it comes into the library as c:NewReadme.txt.
If you pass a character array containing those characters, the
backslash will stay put.
Quote: >I want to replace the single backslash character with 2 backslash
>characters, I am not able to do that in the library where the function
>resides.
Gordon L. Burditt
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| Tue, 18 May 2004 06:47:07 GMT |
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CBFalcone
#3 / 5
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Help in passing the path to a C function - URGENT Quote:
> I have a requirement to pass the path along with the filename
> to a function to perform some read operations. I might use this
> function (as library) in Visual Basic as well as any C/C++
> program.The function definition goes like this :
> int ReadContent(char *filename);
> This function reads the contents of the file name which I pass
> as the parameter.
> This function is called like this :
> int result;
> result = ReadContent("C:\\New\\Readme.txt");
> In VB, the programmer might give the path name as "C:\New\Readme.txt"
> and the function call will not work. I don't have any control over
> the client program and this function resides in a library. So, can
> I do something in the library program by which I can replace the
> single back slash with double slash ? Is it possible or not ?
You don't have any problem. The doubled backslashes are for the
benefit of the C compiler in creating the string in the first
place, and only single backslashes show up in the actual parameter
passed.
--
Available for consulting/temporary embedded and systems.
(Remove "XXXX" from reply address. yahoo works unmodified)
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| Tue, 18 May 2004 08:52:59 GMT |
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Kaz Kylhe
#4 / 5
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Help in passing the path to a C function - URGENT
Quote:
>Hi All, > I have a requirement to pass the path along with the filename to a >function to perform some read operations. I might use this function(as >library) in Visual Basic as well as any C/C++ program.The function >definition goes like this : >int ReadContent(char *filename);
>This function reads the contents of the file name which I pass as the
>parameter.
>This function is called like this :
>int result;
>result = ReadContent("C:\\New\\Readme.txt");
>In VB, the programmer might give the path name as "C:\New\Readme.txt"
>and the function call will not work. I don't have any control over the
>client program and this function resides in a library. So, can I do
>something in the library program by which I can replace the single
>back slash with double slash ? Is it possible or not ?
The double slash is a *written representation* of a single slash character;
that written representation appears only in program source. It is the
object that is manipulated by the C program, not its source code
representation. Similarly, the quotes are also part of the written
representation of a string literal; they are also not part of the
string object.
How you specify string data in Visual Basic source, and how Visual
Basic string objects must be treated when passing into a C module,
these concerns are discussion topics for a Visual Basic newsgroup.
The C language doesn't define any interface to Visual Basic.
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| Tue, 18 May 2004 09:09:39 GMT |
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Barry Schwar
#5 / 5
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Help in passing the path to a C function - URGENT
Quote:
>Hi All, > I have a requirement to pass the path along with the filename to a >function to perform some read operations. I might use this function(as >library) in Visual Basic as well as any C/C++ program.The function >definition goes like this : >int ReadContent(char *filename);
>This function reads the contents of the file name which I pass as the
>parameter.
>This function is called like this :
>int result;
>result = ReadContent("C:\\New\\Readme.txt");
>In VB, the programmer might give the path name as "C:\New\Readme.txt"
>and the function call will not work. I don't have any control over the
>client program and this function resides in a library. So, can I do
>something in the library program by which I can replace the single
>back slash with double slash ? Is it possible or not ?
>Thanks in advance.
>Regards
>Uma
>PS: If I pass a string with a single back slash in it, it is actually
>omitted and it comes into the library as c:NewReadme.txt , so even if
>I want to replace the single backslash character with 2 backslash
>characters, I am not able to do that in the library where the function
>resides.
In c, a string is simply an array of char terminated with a '\0'. Is
it the same in VB? I thought it used an array of char preceded by a
length.
<<Remove the del for email>>
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| Tue, 18 May 2004 11:30:18 GMT |
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