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Determines the number of bytes (expressed as a 32-bit integer) that are available for reading beyond the current read-write pointer in a specified file or socket.


#include <prio.h>

PRInt32 PR_Available(PRFileDesc *fd);


The function has the following parameter:

Pointer to a PRFileDesc object representing a file or socket.


The function returns one of the following values:

  • If the function completes successfully, it returns the number of bytes that are available for reading. For a normal file, these are the bytes beyond the current file pointer.
  • If the function fails, it returns the value -1. The error code can then be retrieved via PR_GetError.


PR_Available works on normal files and sockets. PR_Available does not work with pipes on Win32 platforms.

See Also

If the number of bytes available for reading is out of the range of a 32-bit integer, use PR_Available64.