_CP_readv

_CP_readv is equivalent to the readv BASIC statement.

Depending upon type, _CP_read acts as these BASIC commands:

Type	BASIC Statement
_CP_READV	readv result from expression1, string, expression2
_CP_READVU	readvu result from expression1, string, expression2
_CP_READVUL	readvu result from expression, string, expression2

Syntax

int _CP_readv(int type, CPSTR** result, int expression1, CPSTR* string, int expression2, int* value)

The value parameter returns a 1 if the item is locked. If value is not needed, the user can pass (int*) 0.

The _CP_readv call uses the same optimized read routine as BASIC, which is faster than using AQL and BASIC. expression1 should be an integer file descriptor returned by the _CP_open call.

Description

This function returns -1 if an error occurs. The error code is contained in _CP_errno. If the attribute number is bad, then _CP_errno will contain PE_BADATTR.

Example(s)

/* Reads the first attribute of the item "myid" from "myfile". */

CPSTR * s = _CP_mkstr("myfile");

CPSTR * id = _CP_mkstr("myid");

CPSTR * xx = _CP_str_null;

int f;

_CP_open(&f,_CP_str_null,s);

_CP_readv(_CP_READV, xx, f, id, 1, 0);