I'm reading interesting book [John Ericson's hacking book]
So in that book, he writes binary content to file with "echo -ne" command. But in freeBSD no -e option. Tried to look to another commands, but with no success.
Any advice?
Thanx
Related
I use torque to submit the test script shown blow
#!/bin/bash
#PBS -N test
#PBS -l nodes=1:ppn=1
#PBS -q ser
#PBS -V
#PBS -S /bin/bash
sed 's/a//' <<< aaabbbaaa
sed 's/\(a\)//' <<< aaabbbaaa
sed 's/a\+//' <<< aaabbbaaa
The expect output should be
aabbbaaa
aabbbaaa
bbbaaa
but actually when i use qsub to submit this file, the output becomes
aabbbaaa
aaabbbaaa
aaabbbaaa
The last two commands do not work. And it seems that the character '\' leads to the fault. But why does this happen.
The sed implementation on the server probably has a different syntax than what you have locally.
Without details about the remote system, this is mildly speculative; but look for the manual page and search for an option to enable Extended Regular Expression syntax (usually -E or -r; if available, probably lose the backslash before the regex specials then).
As a partial and obvious workaround, aa* is equivalent to a\+ but no similar workaround exists for grouping.
Maybe also read up on the differences between POSIX Basic Regular Expression syntax (BRE) and ERE; though chances are your PBS system is using something which even predates POSIX if it's legacy big iron.
If you want to write code which is portable between Linux, MacOS, and whatever behemoth dinosaur OS you have on the PBS system, maybe try Perl instead of sed. Even if you can only rely on Perl 4.x constructs, that's a platform which is a lot more uniform (and also a lot more versatile) than trying to figure out how to write portable sed scripts.
perl -pe 's/(a+)//'
System: Arch Linux in VirtualBox 5.1.26 on Windows 10 Host
I try to use perl like sed in the terminal for in place substitution the input file:
perl -i -p -e 's/orig/replace/g' input_file
But I always get:
Can't remove input_file Text file busy, skipping file
This happens only if the file is inside a VirtualBox vboxsf share. With all other tools (sed, mv, vim or whatever) it is no problem to change the file.
This problem seems to be related to:
https://www.virtualbox.org/ticket/2553
https://forums.virtualbox.org/viewtopic.php?t=4437
I can't find any solution googling around :(
Update:
Using perl -i.bak -p -e 's/orig/replace/g' input_file I get a similar message:
Can't rename input_file to input_file.bak: Text file busy, skipping file.
This is exactly the same message as gedit shows:
So it is the same behavior, but googling around I can only find the Gedit topic. It seems noone has noticed this with perl -i.
While you are running a unix OS, you are still using a Windows file system. NTFS doesn't support anonymous files like unix file systems, and Perl -i requires support for anonymous files.
The workaround is to use a temporary files by using -i<ext> (e.g. -i~) instead of -i.
I have same problem. My solution is a bashscript. Copy files to tmp. Search and Replace. Overwrite tmp-files with original-files. Than delete tmp-dir. If you need you can use parameter in script for dynamic search&replace and create an alias for call the script direct and everywhere.
#!/bin/bash
echo "Removing text from .log files..."
echo "Creating tmp-dir..."
mkdir /tmp/myTmpFiles/
echo "Copy .log files to tmp..."
cp -v /home/user/sharedfolder/*.log /tmp/myTmpFiles/
echo "Search and Replace in tmp-files..."
perl -i -p0e 's/orig/replace/g' /tmp/myTmpFiles/*.log
echo "Copy .log to sharedfolder"
cp -v /tmp/myTmpFiles/*.log /home/user/sharedfolder/
echo "Remove tmp-dir..."
rm -vr /tmp/myTmpFiles/
echo "Done..."
Im trying to use js best practices, i use js-best-practices then the error /usr/bin/env: «node\r» "no such file" appear and the program don't run
I appreciate any solution you put. Thanks
Looks like your script file has been created on Windows, the file is DOS format (line endings in DOS). So, you may use a module which converts a file to a Unix format :
brew install dos2unix
sudo dos2unix your_script
or use tr command to remove \r from your file:
cat your_script.js | tr -d '\r' > fixed_script.js
P.S. You can also use vim to convert Windows-style to Unix-style:
vim script
:se ff=unix
:wq
I have some files: file1.txt, file2.txt and I would like to rename them like this: file1.something.txt and file2.something.txt
I looked for some similar questions and I come up with this:
for i in file*.txt; do echo mv $i file*.something.txt; done
but unfortunately the output is:
mv file1.txt file*.something.txt
mv file2.txt file*.something.txt
and therefore only 1 file is created.
Could please somebody help?
(I am using a macbook air, I am not sure if this is relevant)
Thank you very much
Try this :
rename -n 's/\.txt/something.txt' *
(remove -n switch when your tests are OK)
There are other tools with the same name which may or may not be able to do this, so be careful.
If you run the following command (GNU)
$ file "$(readlink -f "$(type -p rename)")"
and you have a result like
.../rename: Perl script, ASCII text executable
and not containing:
ELF
then this seems to be the right tool =)
If not, to make it the default (usually already the case) on Debian and derivative like Ubuntu :
$ sudo update-alternatives --set rename /path/to/rename
(replace /path/to/rename to the path of your perl's rename command.
If you don't have this command, search your package manager to install it or do it manually
Last but not least, this tool was originally written by Larry Wall, the Perl's dad.
Does anybody know which version of sed is required to get option -i to work? I am on CentOS5 and I am getting this error.
If you're going to be using -i with sed you're doing it wrong. sed is a stream editor and it should be used to edit streams, not files, as -i wants to do.
If you want to edit a file, you should be using ed. ed is a line editor and it should be used to edit files. IMO, that's the tool you want to be using.
btw, -i is a GNUism. from the wikipedia:
GNU sed added several new features. The best-known is in-place editing of files (i.e., replace the original file with the result of applying the sed program), which was later included in BSD sed too. This feature is nowadays often used instead of ed scripts: for example,
I don't think you can get -i to work then.
I think this other SO question may help you out:
sed -i + what the same option in SOLARIS
Perhaps the solution isn't as nice as sed -i, however.