author | Dominic Pinkman <Dominic.Pinkman@Nokia.com> |
Fri, 22 Jan 2010 18:26:19 +0000 | |
changeset 1 | 25a17d01db0c |
child 3 | 46218c8b8afa |
permissions | -rw-r--r-- |
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25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
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<?xml version="1.0" encoding="utf-8"?> |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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<!-- This component and the accompanying materials are made available under the terms of the License |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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"Eclipse Public License v1.0" which accompanies this distribution, |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
25a17d01db0c
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<!-- Initial Contributors: |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
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Nokia Corporation - initial contribution. |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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Contributors: |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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--> |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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<!DOCTYPE concept |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
25a17d01db0c
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<concept xml:lang="en" id="GUID-A4ECB450-02DA-5E85-91AC-4C8BDE0B9B58"><title>Writing, Reading and Seeking from a Shared Memory</title><prolog><metadata><keywords/></metadata></prolog><conbody><p>Use the <xref href="GUID-4BABB86A-966A-3535-BD35-568338359825.dita"><apiname>write()</apiname></xref> function to write to shared memory </p> <p>Use the <xref href="GUID-99F32AF6-7248-37B7-901A-76FA23DBCD8A.dita"><apiname>read()</apiname></xref> function to read data from shared memory. </p> <p>Use the <xref href="GUID-84F93A85-9DD3-3D5A-98A7-769E6EDA77D1.dita"><apiname>lseek()</apiname></xref> function to set the file offset associated with a shared memory file descriptor </p> <p>Example: </p> <codeblock id="GUID-60F8E5BB-57F5-5520-A061-43D71436543D" xml:space="preserve">#include <stdio.h> |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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#include <sys/mman.h> |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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#include <fcntl.h> |
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#include <unistd.h> |
25a17d01db0c
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#include <errno.h> |
25a17d01db0c
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int main(void) |
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{ |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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int fd; //File descriptor |
25a17d01db0c
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int ret = 0; |
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if((fd = shm_open("page", O_RDWR|O_CREAT, 0666)) < 0) |
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{ |
25a17d01db0c
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printf("Shared memory creation failed with errno %d\n", errno); |
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} |
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else |
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{ |
25a17d01db0c
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printf("Shared memory creation was successful\n"); |
25a17d01db0c
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} |
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if((ret = write(fd, "symbian", 7)) < 0) |
25a17d01db0c
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{ |
25a17d01db0c
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printf("Writing into shared memory failed with errno %d\n", errno); |
25a17d01db0c
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} |
25a17d01db0c
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else |
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Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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{ |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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printf("Writing into shared memory was successful\n"); |
25a17d01db0c
Addition of the PDK content and example code for Documentation_content according to Feature bug 1607 and bug 1608
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} |
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if((ret = lseek(fd, -6, SEEK_END)) < 0) |
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{ |
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printf("Seeking from end failed with errno %d\n", errno); |
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} |
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else |
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{ |
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printf("lseek was successful\n"); |
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} |
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char buf[7]; |
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if((ret = read(fd, (void*)buf, 6)) < 0) |
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{ |
25a17d01db0c
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printf("Reading from shared memory failed with errno %d\n", errno); |
25a17d01db0c
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} |
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else |
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{ |
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printf("Reading from shared memory was successful\n"); |
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printf("Buffer read = %s\n", buf); |
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} |
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close(fd);//closing the file descriptor |
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if((ret = shm_unlink("page")) < 0) |
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{ |
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printf("Shared memory unlinking failed with errno %d\n", errno); |
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} |
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else |
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{ |
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printf("Shared memory unlinking was successful\n"); |
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} |
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return ret; |
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}</codeblock> </conbody><related-links><link href="GUID-9AC6774A-41E9-5298-8696-0A317A09E1E9.dita"><linktext>Librt Overview</linktext> </link> <link href="GUID-BE70DCBF-366A-5054-B0F1-7FCEF45FC735.dita"><linktext>Creating and Unlinking a File |
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Descriptor from a Shared Memory</linktext> </link> <link href="GUID-8F6D6934-8FF0-5045-8AB1-74384BE792EA.dita"><linktext>Retrieving Information about a |
25a17d01db0c
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Shared Memory Object</linktext> </link> <link href="GUID-66402932-5C44-556B-A7AC-1C2D245C8B05.dita"><linktext>Clocks and Timers Tutorial</linktext> </link> </related-links></concept> |