Sponsored Content
Top Forums Programming Copying 1024 bytes data in 3-bytes chunk Post 302513313 by royalibrahim on Tuesday 12th of April 2011 11:25:32 PM
Old 04-13-2011
Quote:
Originally Posted by disaster
The dd function you posted would actually copy three times a junk of 1024 bytes, ie. 3K bytes in total.
But I understand your question in such a way that you want to read 3 bytes in at once and do that same 300 times, right?

memcpy() is not the right function when you want to store it into a file. You simply need to store 3 bytes in a buffer of char buf[3]; and then use fwrite to write this buffer into a file. Wrap a loop around it so it gets done until 1024bytes are written and you're done
Yes, you are absolutely right!! Thanks a ton for the hint Smilie
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Remove first N bytes and last N bytes from a binary file on AIX.

Hi all, Does anybody know or guide me on how to remove the first N bytes and the last N bytes from a binary file? Is there any AWK or SED or any command that I can use to achieve this? Your help is greatly appreciated!! Best Regards, Naveen. (1 Reply)
Discussion started by: naveendronavall
1 Replies

2. Shell Programming and Scripting

80 bytes per line ???

I am creating ASCII file from Oracle procedure into Unix box. I undertstand there is NO CRLF as I am writing it into one complete string .. but need to know what is best way to format the file with 80bytes per line only before handing over to another program. Thanks in advance regards... (14 Replies)
Discussion started by: u263066
14 Replies

3. UNIX for Dummies Questions & Answers

Files with zero bytes

Hi All, I want to find zero byte files in the given folder for the given day. I know we can use find . -size 0 -mtime 0 But is there an option for file creation.? ls -lart | grep ' 0 Apr 24' will also work. Also is there any alternative using awk ? I want to know how to use awk in... (1 Reply)
Discussion started by: preethgideon
1 Replies

4. IP Networking

Command to ping 1500 bytes of data to a destination system

Hi All, I want to ping 1500 bytes of data from a pc to another pc in the network. What is command used for the same? Thanks (2 Replies)
Discussion started by: rvan
2 Replies

5. Shell Programming and Scripting

Error PHP Fatal error: Allowed memory size of 67108864 bytes exhausted(tried to allocate 401 bytes)

While running script I am getting an error like Few lines in data are not being processed. After googling it I came to know that adding such line would give some memory to it ini_set("memory_limit","64M"); my input file size is 1 GB. Is that memory limit is based on RAM we have on... (1 Reply)
Discussion started by: elamurugu
1 Replies

6. UNIX for Dummies Questions & Answers

X bytes of 0, Y bytes of random data, Z bytes of 5, T bytes of 1. ??

Hello guys. I really hope someone will help me with this one.. So, I have to write this script who: - creates a file home/student/vmdisk of 10 mb - formats that file to ext3 - mounts that partition to /mnt/partition - creates a file /mnt/partition/data. In this file, there will... (1 Reply)
Discussion started by: razolo13
1 Replies

7. Shell Programming and Scripting

Shell script - entered input(1-40 bytes) needs to be converted exactly 40 bytes

hello, suppose, entered input is of 1-40 bytes, i need it to be converted to 40 bytes exactly. example: if i have entered my name anywhere between 1-40 i want it to be stored with 40 bytes exactly. enter your name: donald duck (this is of 11 bytes) expected is as below - display 11... (3 Replies)
Discussion started by: shravan.300
3 Replies

8. Shell Programming and Scripting

Get file's first x bytes

is there a better way to do this: head -c 10000k /var/dump.log | head -c 6000k unfortunately, the "-c" option is not available on sun solaris. so i'm looking at "dd". but i dont know how to use it to achieve the same exact goal as the above head command. this needs to work on both solaris... (5 Replies)
Discussion started by: SkySmart
5 Replies

9. What is on Your Mind?

Definition of Bytes

A byte is the smallest unit of storage which can be accessed in a computer's memory- either in RAM or ROM.It also holds exactly 8 bits.But its old view one byte was sufficient to hold one 8 bit character.Modern days especially on .NET or international versions of Win 32, 16 bits is needed. ... (2 Replies)
Discussion started by: stoudtLion
2 Replies

10. Programming

Best way to axe N bytes from the right?

say that i have strings that end in "text" foo.9.text, bar.10.text, baz.11.text and i want a C function to chop off the last four characters and replace each string with a '\0'; obviously with error-checking. Any ideas? TIA! (7 Replies)
Discussion started by: Gary Kline
7 Replies
zipios::BackBuffer(3)					     Library Functions Manual					     zipios::BackBuffer(3)

NAME
zipios::BackBuffer - A BackBuffer instance is useful for reading the last part of a file in an efficient manner, when it is not known exactly how far back (towards the front!) to go, to find the start of the desired data block. SYNOPSIS
#include <backbuffer.h> Inherits vector< unsigned char >. Public Member Functions BackBuffer (istream &is, VirtualSeeker vs=VirtualSeeker(), int chunk_size=1024) BackBuffer constructor. int readChunk (int &read_pointer) Reads another chunk and returns the size of the chunk that has been read. Detailed Description A BackBuffer instance is useful for reading the last part of a file in an efficient manner, when it is not known exactly how far back (towards the front!) to go, to find the start of the desired data block. BackBuffer is a vector< unsigned char > that fills itself with data from a file by reading chunks from the end of the file progressing towards the start. Upon construction the BackBuffer instance is associated with a file and a chunksize can be specified. To read a chunk of the file into the BackBuffer call readChunk(). Definition at line 32 of file backbuffer.h. Constructor &; Destructor Documentation zipios::BackBuffer::BackBuffer (istream &is, VirtualSeekervs = VirtualSeeker(), intchunk_size = 1024) [inline, explicit] BackBuffer constructor. Parameters: is The istream to read the data from. The stream must be seekable, as BackBuffer will reposition the file position to read chunks from the back of the file. chunk_size specifies the size of the chunks to read the file into the BackBuffer in. Exceptions: FCollException Thrown if the VirtualSeeker vs that has been specified is invalid for the istream is. Definition at line 61 of file backbuffer.h. Member Function Documentation int zipios::BackBuffer::readChunk (int &read_pointer) [inline] Reads another chunk and returns the size of the chunk that has been read. Returns 0 on I/O failure. Parameters: read_pointer When a new chunk is read in the already stored bytes change position in the BackBuffer. read_pointer is assumed by readChunk() to be a pointer into a position in the BackBuffer, and is updated to point to the same position in the file as it pointed to before the new chunk was read. Definition at line 75 of file backbuffer.h. Author Generated automatically by Doxygen for Zipios++ from the source code. Zipios++ Mon Oct 10 2011 zipios::BackBuffer(3)
All times are GMT -4. The time now is 05:20 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy