open Function

Open a file.

Attention: This interface function is implemented only by MPLAB XC32 C compilers.

Include

None

Prototype

int open(const char *name, int access, int mode);

Arguments

 name name of the file to be opened access access method to open file mode type of access permitted

Return Value

If successful, the function returns a file handle: a small positive integer. This handle is then used on subsequent low-level file I/O operations. A return value of -1 indicates an error, and the global variable errno is set to the value of the symbolic constant, EFOPEN, defined in <errno.h>.

Remarks

This function is implemented as a stub that must be completed to suite the application.

This helper function is called by the Standard C Library functions fopen() and freopen().

The access flag is a union of one of the following access methods and zero or more access qualifiers:
• 0 – Open a file for reading.
• 1 – Open a file for writing.
• 2 – Open a file for both reading and writing.
The following access qualifiers must be supported:
• 0x0008 – Move file pointer to end-of-file before every write operation.
• 0x0100 – Create and open a new file for writing.
• 0x0200 – Open the file and truncate it to zero length.
• 0x4000 – Open the file in text (translated) mode.
• 0x8000 – Open the file in binary (untranslated) mode.
The mode parameter may be one of the following:
• 0x0100 – Reading only permitted.
• 0x0080 – Writing permitted (implies reading permitted).

Default Behavior

As distributed, the parameters are passed to the host file system through the simulator. The return value is the value returned by the host file system.

Source File

open.c