|
Unix VPS
Support
FAQ
Network
Miscellaneous
|
| srec_binary(5) | FreeBSD File Formats Manual | srec_binary(5) |
NAME
srec_binary - binary file formatDESCRIPTION
It is possible to read and write binary files using srec_cat(1).File Holes
A file hole is a portion of a regular file that contains NUL characters and is not stored in any data block on disk. Holes are a long‐standing feature of Unix files. For instance, the following Unix command creates a file in which the first bytes are a hole:$ echo -n "X" | dd of=/tmp/hole bs=1024 seek=6 $
Now /tmp/hole has 6,145 characters (6,144 NUL characters plus an X character), yet the file occupies just one data block on disk.
File holes were introduced to avoid wasting disk space. They are used extensively by database applications and, more generally, by all applications that perform hashing on files.
See http://www.oreilly.com/catalog/linuxkernel2/chapter/ch17.pdf for more information.
Reading
The size of binary files is taken from the size of the file on the file system. If the file has holes these will read as blocks of NUL (zero) data, as there is no elegant way to detect Unix file holes. In general, you probably want to use the -unfill filter to find and remove large swathes of zero bytes.Writing
In producing a binary file, srec_cat(1) honours the address information and places the data into the binary file at the addresses specified in the hex file. This usually results on holes in the file. Sometimes alarmingly large file sizes are reported as a result.If you are on a brain‐dead operating system without file holes then there are going to be real data blocks containing real zero bytes, and consuming real amounts of disk space. Upgrade - I suggest Linux.
To make a file of the size you expect, use
to find the lowest address, then use
where n is the lowest address present in the foo.s19 file, as reported by srec_info(1). The negative offset serves to move the data down to have an origin of zero.
SEE ALSO
- srec_input(1)
- for a description of the -unfill filter
- srec_examples(1)
- has a section about binary files, and ways of automagically offseting the
data back to zero in a single command.
COPYRIGHT
SRrecord version 1.64Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 Peter Miller
The SRrecord program comes with ABSOLUTELY NO WARRANTY; for
details use the 'SRrecord -VERSion License' command. This is free
software and you are welcome to redistribute it under certain conditions;
for details use the 'SRrecord -VERSion License' command.
MAINTAINER
| Scott Finneran | E‐Mail: | scottfinneran@yahoo.com.au |
| Peter Miller | E‐Mail: | pmiller@opensource.org.au |
| SRecord | Reference Manual |
Visit the GSP FreeBSD Man Page Interface.
Output converted with ManDoc.