/* * Copyright (c) 2008 Apple Inc. All rights reserved. * * @APPLE_DTS_LICENSE_HEADER_START@ * * IMPORTANT: This Apple software is supplied to you by Apple Computer, Inc. * ("Apple") in consideration of your agreement to the following terms, and your * use, installation, modification or redistribution of this Apple software * constitutes acceptance of these terms. If you do not agree with these terms, * please do not use, install, modify or redistribute this Apple software. * * In consideration of your agreement to abide by the following terms, and * subject to these terms, Apple grants you a personal, non-exclusive license, * under Apple's copyrights in this original Apple software (the "Apple Software"), * to use, reproduce, modify and redistribute the Apple Software, with or without * modifications, in source and/or binary forms; provided that if you redistribute * the Apple Software in its entirety and without modifications, you must retain * this notice and the following text and disclaimers in all such redistributions * of the Apple Software. Neither the name, trademarks, service marks or logos of * Apple Computer, Inc. may be used to endorse or promote products derived from * the Apple Software without specific prior written permission from Apple. Except * as expressly stated in this notice, no other rights or licenses, express or * implied, are granted by Apple herein, including but not limited to any patent * rights that may be infringed by your derivative works or by other works in * which the Apple Software may be incorporated. * * The Apple Software is provided by Apple on an "AS IS" basis. APPLE MAKES NO * WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED * WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN * COMBINATION WITH YOUR PRODUCTS. * * IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR * DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF * CONTRACT, TORT (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF * APPLE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * @APPLE_DTS_LICENSE_HEADER_END@ */ #include <assert.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <sys/errno.h> #include <dispatch/dispatch.h> void readFileData(void* theSource) { char buffer[10]; size_t estimated = dispatch_source_get_data(theSource); printf("Estimated bytes available: %ld\n", estimated); ssize_t actual = read(dispatch_source_get_handle(theSource), buffer, sizeof(buffer)); if (actual == -1) { if (errno != EAGAIN) { perror("read"); exit(-1); } } else { if (estimated>actual) { printf(" bytes read: %ld\n", actual); } else { // end of file has been reached. printf(" last bytes read: %ld\n", actual); dispatch_source_cancel(theSource); } } } void cancelSource(void* theSource) { close(dispatch_source_get_handle(theSource)); dispatch_release(theSource); dispatch_release(dispatch_get_current_queue()); printf("Everything is finished, goodbye.\n"); exit(0); } int main(int argc, char* argv[]) { int infd; dispatch_source_t fileSource; if (argc != 2) { fprintf(stderr, "usage: %s file ...\n", argv[0]); exit(1); } infd = open(argv[1], O_RDONLY); if (infd == -1) { perror(argv[1]); exit(1); } if (fcntl(infd, F_SETFL, O_NONBLOCK) != 0) { perror(argv[1]); exit(1); } fileSource = dispatch_source_create(DISPATCH_SOURCE_TYPE_READ, infd, 0, dispatch_queue_create("read source queue",NULL)); dispatch_source_set_event_handler_f( fileSource, readFileData); dispatch_source_set_cancel_handler_f( fileSource, cancelSource); // setting the context pointer to point to the source itself means the functions will get the source // as a paremeter, from there they can get all the information they need. dispatch_set_context(fileSource, fileSource); dispatch_resume(fileSource); dispatch_main(); return 0; }