read.c File Reference

Functions
__LDDK_READ_TYPE	can_read (__LDDK_READ_PARAM)
	ssize_t read(int fd, void *buf, size_t count); the read system call

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Detailed Description

Author:

Heinz-Jürgen Oertel, port GmbH

Revision

1.2

Date

2006/09/08 09:47:37

Module Description see Doxygen Doc for all possibilities

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Function Documentation

__LDDK_READ_TYPE can_read (  __LDDK_READ_PARAM   )

ssize_t read(int fd, void *buf, size_t count); the read system call Parameters: fd  The descriptor to read from. buf  The destination data buffer (array of CAN canmsg_t). count  The number of bytes to read. read() attempts to read up to count CAN messages (not bytes! ) from file descriptor fd into the buffer starting at buf. buf must be large enough to hold count times the size of one CAN message structure canmsg_t. int got; canmsg_t rx[80]; // receive buffer for read() got = read(can_fd, rx , 80 ); if( got > 0) { ... } else { // read returned with error fprintf(stderr, "- Received got = %d\n", got); fflush(stderr); } ERRORS the following errors can occur EINVAL buf points not to an large enough area, Returns: On success, the number of CAN messages read is returned (zero indicates end of file). It is not an error if this number is smaller than the number of messages requested; this may happen for example because fewer messages are actually available right now, or because read() was interrupted by a signal. On error, -1 is returned, and errno is set appropriately.

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