vrb_read_min(3) 					      VRB Programmer's Manual						   vrb_read_min(3)

NAME

       vrb_read_min - read a minimum of data into a VRB

LIBRARY

       -lvrb

SYNOPSIS

       #include <vrb.h>

       size_t vrb_read_min(vrb_p vrb, int fd, size_t maxsize, size_t minsize);

DESCRIPTION

       vrb_read_min  reads  a  minimum	amount	of data from a specified open file descriptor using read(2) into the specified virtual ring buffer
       until the specified maximum length has been read, the buffer is full, or end-of-file, or an error is returned (including EAGAIN or  EWOULD-
       BLOCK  for  a  non-blocking descriptor).  If there is insufficient space in the buffer to read the minimum amount, then read(2) will not be
       called.

ARGUMENTS

       vrb_p vrb
       specifies which virtual ring buffer.

       int fd
       specifies the open file descriptor to read from

       size_t maxsize
       specifies the maximum length to read, or ~0 for unlimited.

       size_t minsize
       specifies the minimum length to read.

RETURN VALUE

       size_t
       If successful, the actual length of data read into the buffer is returned.  If the minimum amount of space was not available to read  into,
       0  is returned.	If end-of-file occurs, the return value is ~0 and errno is 0.  If an error occurs from read(2), the return value is ~0 and
       errno is set by read(2).

ERRORS

       If an error is returned, then errno will have one of the following values:

       0      An end-of-file has occurred.  Note that this is a different way of returning an end-of-file condition than read(2) uses.

       EINVAL An invalid virtual ring buffer pointer was specified.

SEE ALSO

       vrb(3),	vrb_capacity(3),  vrb_data_len(3),  vrb_data_ptr(3),  vrb_destroy(3),  vrb_get(3),   vrb_get_min(3),   vrb_give(3),   vrb_init(3),
       vrb_init_opt(3),   vrb_is_empty(3),  vrb_is_full(3),  vrb_is_not_empty(3),  vrb_is_not_full(3),	vrb_move(3),  vrb_new(3),  vrb_new_opt(3),
       vrb_put(3), vrb_put_all(3), vrb_read(3),  vrb_resize(3),  vrb_space_len(3),  vrb_space_ptr(3),  vrb_take(3),  vrb_uninit(3),  vrb_write(3),
       vrb_write_min(3), read(2)

vrb								    2002-09-30							   vrb_read_min(3)