Disk read/write perfomance in linux
/dev/zero is a special file. It's contents stem from a device driver. All write operations on /dev/zero are guaranteed to succeed. A bit more about that here and here Without specifying of dd prints to stdout. Thus the data which the terminal receives has to be formatted and printed. The...
Bash shell scripting: How to replace characters at specific byte offsets
Please check my comment about about newline offset. Assuming this is correct (note I have changed your offset array), then I think this should work for you: #!/bin/bash read -r -d '' offsetsArray=("2" "8" "9" "15") txt="${REPLY}" for i in "${offsetsArray[@]}"; do txt="${txt:0:$i-1}*${txt:$i}" done printf "%s" "$txt" Explanation: read -d...
Using dd command through Python's subprocess module
dd does not output anything to stdout, so your result is correct. However, it does output to stderr. Pass in stderr=subprocess.STDOUT to get the stderr output: >>> o = subprocess.check_output( ['dd', 'if=/etc/resolv.conf', 'of=r'], stderr=subprocess.STDOUT) >>> print(o) b'0+1 records in\n0+1 records out\n110 bytes (110 B) copied, 0.00019216 s, 572 kB/s\n' ...
testing - intentionally corrupt a .Z file using 'dd'
You could just have used a hex editor like hexedit. Since you ask though, dd if=/dev/urandom of=yourfile.z bs=1024 seek=$((RANDOM%10)) count=1 conv=notrunc will rewrite garbage to a random 1024b block out of the first ten in a file....
How can I create a file with specific values using the dd command?
Only with dd you can't do this. dd only copies a byte stream from its input to its output, it can't generate anything. You need to have same source for the dd which generates the needed data from. The nearest which you can do that would be a simple shellscript,...
Highest block size for dd command
You could go higher, but it probably won't make any difference. If you go too high, things might actually slow down. Different SSD devices have different performance profiles. There is no universal, ultimate, answer that's right for every SSD device that exists in this entire world. The only way to...
How can I convert E01 image file to dd image file?
dd,computer-forensics,diskimage
tsk_recover (and all of The Sleuth Kit and Autopsy tools) support E01 if you compile it with libewf (http://sourceforge.net/projects/libewf/). If you want the raw image though, libewf has tools to do the conversion and you can use 'img_cat' in TSK to do it (but it requires you to have compiled...
dd returns permission denied even as root
permissions,centos,root,dd,denied
It's a virtual filesystem (container). You cannot access directly even as root-- it's only available from the actual system that the virtual machine is running on.
Appending 0's to make 1MB file with dd
You can tell dd to seek to the 1M position in the file, which has the effect of making its size at least 1M: dd if=/dev/null of=abc.bin obs=1M seek=1 If you want to ensure that dd only extends, never truncates the file, add conv=notrunc: dd if=/dev/null of=abc.bin obs=1M seek=1 conv=notrunc...
Change the header in a huge file without rewriting the whole file
If you do not want to rewrite the binary data, then the length of the header in bytes must not change. You can do this by padding with spaces or zeroes or whatever works for your format. The first step is to create the header that you want. You may...
Is using dd to read from /dev/ttyUSB0 the best option?
Note that the count parameter to dd specifies a number of bytes, not lines, to read. I'll assume you want to a line, in which case dd is the wrong tool to use. # Exit with status 1 if nothing read in 5 seconds if read -r -t 5 line...
Create a file in linux of size 128k which has data has 128k ones
Why do you require the fastest solution, and fatest by what metric? Writing the bytes to the disk is probably going to be the bottleneck anyway, so it doesn't matter really how fast you generate them, as long as it's faster than the write rate of the output medium. dd...
Is it safe to backup a partition with dd? [closed]
Yes it will work and yes, as you say, if you have any hidden, old data there, it will be stored in your image as well. So if you are worried about not storing those files, just use tar. If you want to zero unused space you can use zerofree,...
which log file or how do I locate this log file?
If you're talking about the file being created by dd, it's either going to be whatever file you specified with the of= option, or standard output, possibly redirected. That's the way dd works: it writes to standard output by default but you can override this by specifying the output file...