Why fopen("FineName.bin","rb") fails to return file handler?

[asifjavaid]

Hi,

I am in problem. I have written some code in VC++.NET 2008. It is using third part AMT SDK. It is using file handling of C using fopen() function. The file are opened in binary mode (rb).

It is working very perfect according to our requirment on my local machine environment. But when i upload the same code on another machine with same operating system and environment, then I become surprise to notice that fopen() function doesn't works.

Can anyone please tell me my why FILE *fptr = fopen("fileName.bin","rb") fails to return a handle for a bin file. It is returning a NULL pointer?

I know some reasons that, files must be on a correct path and files must not be used by another process. But currently nothing is happening out of these reasons. The files are already placed on their correct path and are also not in any used.

I am calling fopen in a loop of 3 count. In first attempt of for loop, the file is open by fopen() but on second attempt, fopen() still returning a null pointer.

Please guide me in this case. I become stuck here. why fopen("fileName.bin","rb") fails and returning NULL value.

the errorno returned is here

The error number is 9

EBADF Bad file number 9

Here is my sample code

int file_count = 3;
for( int f=0; f<file_count; f++ )
	{
		FILE *f_in = NULL;
		size_t items;
		int buf_size;
		void *buf_ptr = NULL;

		//f_in = fopen(argv[f],"rb");
		if(f==0)
			f_in = fopen("video_output_interlaced_output.bin","rb");
		else if(f==1)
			f_in = fopen("audio_channel_1_output.bin","rb");
		else
			f_in = fopen("audio_channel_2_output.bin","rb");

		if( f_in == NULL )
		{
			fprintf(fptr,"ERROR: Could not open '%s'\n", argv[f] );
			perror("ERROR: Could not open file");
			fprintf(fptr,"ERROR: number is  '%d'\n", errno);
			fclose(fptr);
			return 1;
		}

		//fprintf(fptr,"\nOpening the file '%s'",argv[f]);

		items = fread(&buf_size,sizeof(int),1,f_in);

Many Thanks,

--

Regards,

Asif

[Salem]

Do you close f_in at the end of the loop?
What do you do with buf_ptr ?

[cikara21]

The fopen() function shall fail if:

[EACCES]
Search permission is denied on a component of the path prefix, or the file exists and the permissions specified by mode are denied, or the file does not exist and write permission is denied for the parent directory of the file to be created.

[EINTR]
A signal was caught during fopen().

[EISDIR]
The named file is a directory and mode requires write access.

[ELOOP]
A loop exists in symbolic links encountered during resolution of the path argument.

[EMFILE]
File descriptors are currently open in the calling process.

[ENAMETOOLONG]
The length of the filename argument exceeds {PATH_MAX} or a pathname component is longer than {NAME_MAX}.

[ENFILE]
The maximum allowable number of files is currently open in the system.

[ENOENT]
A component of filename does not name an existing file or filename is an empty string.

[ENOSPC]
The directory or file system that would contain the new file cannot be expanded, the file does not exist, and the file was to be created.

[ENOTDIR]
A component of the path prefix is not a directory.

[ENXIO]
The named file is a character special or block special file, and the device associated with this special file does not exist.

[EOVERFLOW]
The named file is a regular file and the size of the file cannot be represented correctly in an object of type off_t.

[EROFS]
The named file resides on a read-only file system and mode requires write access.
The fopen() function may fail if:

[EINVAL]
The value of the mode argument is not valid.

[ELOOP]
More than {SYMLOOP_MAX} symbolic links were encountered during resolution of the path argument.

[EMFILE]
streams are currently open in the calling process.

[EMFILE]
streams are currently open in the calling process.

[ENAMETOOLONG]
Pathname resolution of a symbolic link produced an intermediate result whose length exceeds {PATH_MAX}.

[ENOMEM]
Insufficient storage space is available.

[ETXTBSY]
The file is a pure procedure (shared text) file that is being executed and mode requires write access.

:D :D :D