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Solved
stream in and stream out simultaneously
Posted on 2004-03-20
HI
I am trying to stream a file in and then stream out the line to a different file
example:
CString fileSource ="in.txt";
CString fileDest ="out.txt";
FILE *in_stream;
FILE *out_stream;
char line[100];
if( (in_stream = fopen( fileSource, "r" )) != NULL )
{
if(out_stream = fopen(fileDest,"w")) !=NULL)
while( fgets( line, 100, in_stream )){
.... //do something with the line and then output it
fprintf(out_stream, "%s", line);
}
fclose(out_stream);
}
fclose( in_stream );
}
both files are opened and the first line is read.
after that nothing happens.
I cannot get this to work.
I have heard of memory mapping files but I have no Idea how to do this, or if it would solve my problem.
Thanks for any suggestions.
I am trying to stream a file in and then stream out the line to a different file
example:
CString fileSource ="in.txt";
CString fileDest ="out.txt";
FILE *in_stream;
FILE *out_stream;
char line[100];
if( (in_stream = fopen( fileSource, "r" )) != NULL )
{
if(out_stream = fopen(fileDest,"w")) !=NULL)
while( fgets( line, 100, in_stream )){
.... //do something with the line and then output it
fprintf(out_stream, "%s", line);
}
fclose(out_stream);
}
fclose( in_stream );
}
both files are opened and the first line is read.
after that nothing happens.
I cannot get this to work.
I have heard of memory mapping files but I have no Idea how to do this, or if it would solve my problem.
Thanks for any suggestions.
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8 Comments
Active 2 days ago
Could you post the full code? The above looks OK. What e.g. is
//do something with the line and then output it
standing for?
//do something with the line and then output it
standing for?
hi,
fgets stops reading after getting a new line character. it returns NULL and your loop stops.
so read till eof. using fgetc.
if( (in_stream = fopen( fileSource, "r" )) != NULL )
{
if(out_stream = fopen(fileDest,"w")) !=NULL)
while((i = fgetc(in_stream)) != EOF){
fputc(i,out_stream);
}
fclose(out_stream);
}
fclose( in_stream );
}
fgets stops reading after getting a new line character. it returns NULL and your loop stops.
so read till eof. using fgetc.
if( (in_stream = fopen( fileSource, "r" )) != NULL )
{
if(out_stream = fopen(fileDest,"w")) !=NULL)
while((i = fgetc(in_stream)) != EOF){
fputc(i,out_stream);
}
fclose(out_stream);
}
fclose( in_stream );
}
Hi,
I used fgets because it read in the text file line by line.
fgetc reads in characters not lines...
Is there any way to read the entire line?
I used fgets because it read in the text file line by line.
fgetc reads in characters not lines...
Is there any way to read the entire line?
...actually the problem is that the project was upgraded from VC++ 5 to VC++ 7
The file streaming didn't work.
To fix the error I simply created a new Console project in VC++ and added MFC support.
After cutting and pasting the code into the new VC++ 7 project. The streaming worked.
The file streaming didn't work.
To fix the error I simply created a new Console project in VC++ and added MFC support.
After cutting and pasting the code into the new VC++ 7 project. The streaming worked.
hi,
The fgets just worked fine. It should work.
try copying other files. do ypu get the same errror.
Sometimes you get those type of errors if you try to copy binary files. Are u trying to copy binary files.
For text files, your code works fine.
another cause might be that. you are using it in a function. If u call the function first time it will copy. close the handle. In the second time it start copying from the first. In case your src is changing, at the end of your program, you will ger the last entry only.
to avoid this open the file just once (somewhere in main()) and close in the end of the program. This can solve your problem.
If you just want to try out, open fileDest as "a+"(append).
regards manish
The fgets just worked fine. It should work.
try copying other files. do ypu get the same errror.
Sometimes you get those type of errors if you try to copy binary files. Are u trying to copy binary files.
For text files, your code works fine.
another cause might be that. you are using it in a function. If u call the function first time it will copy. close the handle. In the second time it start copying from the first. In case your src is changing, at the end of your program, you will ger the last entry only.
to avoid this open the file just once (somewhere in main()) and close in the end of the program. This can solve your problem.
If you just want to try out, open fileDest as "a+"(append).
regards manish
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