I am using GNU parallel in Ubuntu 20.04.2. I tried to use the --plus option for parameter manipulation. But I couldn't get it to work, even as simple as the following command:
$ parallel --plus echo {/.gz/.st} ::: test.gz
$ {/.gz/.st} test.gz
I wonder what I did wrong.
It was introduced in 20170322.
Your version is probably older.
Related
Dipping my toes into Bash coding for the first time (not the most experienced person with Linux either) and I'm trying to read the version from the version.php inside a container at:
/config/www/nextcloud/version.php
To do so, I run:
docker exec -it 1c8c05daba19 grep -eo "(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?" /config/www/nextcloud/version.php
This uses a semantic versioning RegEx pattern (I know, a bit overkill, but it works for now) to read and extract the version from the line:
$OC_VersionString = '20.0.1';
However, when I run the command it tells me No such file or directory, (I've confirmed it does exist at that path inside the container) and then proceeds to spit out the entire contents of the file it just said doesn't exist?
grep: (0|[1-9]\d*).(0|[1-9]\d*).(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-])(?:.(?:0|[1-9]\d|\d*[a-zA-Z-][0-9a-zA-Z-]))))?(?:+([0-9a-zA-Z-]+(?:.[0-9a-zA-Z-]+)*))?: No such file or directory
/config/www/nextcloud/version.php:$OC_Version = array(20,0,1,1);
/config/www/nextcloud/version.php:$OC_VersionString = '20.0.1';
/config/www/nextcloud/version.php:$OC_Edition = '';
/config/www/nextcloud/version.php:$OC_VersionCanBeUpgradedFrom = array (
/config/www/nextcloud/version.php: 'nextcloud' =>
/config/www/nextcloud/version.php: 'owncloud' =>
/config/www/nextcloud/version.php:$vendor = 'nextcloud';
Anyone able to spot the problem?
Update 1:
For the sake of clarity, I'm trying to run this from a bash script. I just want to fetch the version number from that file, to use it in other areas of the script.
Update 2:
Responding to the comments, I tried to login to the container first, and then run the grep, and still get the same result. Then I cat that file and it shows it's contents no problem.
Many containers don't have the GNU versions of Unix tools and their various extensions. It's popular to base containers on Alpine Linux, which in turn uses a very lightweight single-binary tool called BusyBox to provide the base tools. Those tend to have the set of options required in the POSIX specs, and no more.
POSIX grep(1) in particular doesn't have an -o option. So the command you're running is
grep \
-eo \ # specify "o" as the regexp to match
"(regexps are write-only)" \ # a filename
/config/www/nextcloud/version.php # a second filename
Notice that the grep output in the interactive shell only contains lines with the letter "o", but not for example the line just containing array.
POSIX grep doesn't have an equivalent for GNU grep's -o option
Print only the matched (non-empty) parts of matching lines, with each such part on a separate output line. Output lines use the same delimiters as input....
but it's easy to do that with sed(1) instead. Ask it to match some stuff, the regexp in question, and some stuff, and replace it with the matched group.
sed -e 's/.*\(any regexp here\).*/\1/' input-file
(POSIX sed only accepts basic regular expressions, so you'll have to escape more of the parentheses.)
Well, for any potential future readers, I had no luck getting grep to do it, I'm sure it was my fault somehow and not grep's, but thanks to the help in this post I was able to use awk instead of grep, like so:
docker exec -it 1c8c05daba19 awk '/^\$OC_VersionString/ && match($0,/\047[0-9]+\.[0-9]+\.[0-9]+\047/){print substr($0,RSTART+1,RLENGTH-2)}' /config/www/nextcloud/version.php
That ended up doing exactly what I needed:
It logs into a docker container.
Scans and returns just the version number from the line I am looking for at: /config/www/nextcloud/version.php inside the container.
Exits stage left from the container with just the info I needed.
I can get right back to eating my Hot Cheetos.
I have a variable in my jboss cli file, let's call it ${FOO}.
I can see that the variable is set in my Dockerfile, if I:
RUN echo ${FOO}
I see the value printed.
I have a foo.cli file which contains a line similar to:
/system-property=foo:add(value="${FOO}")
and when I run jboss-cli.sh foo.cli
I get:
Cannot resolve expression ${FOO}.
Is there a way to pass a variable from Docker to the file argument to jboss-cli.sh ?
I've tried removing the quotes around ${FOO} also in the system-property line but no luck.
This is due to the fact that the CLI does not treat values the same as names. In short, operation names, parameter names, header names and values, command names as well as command argument names are resolved automatically. Parameter and argument values aren’t. To fix this, we need to set resolve-parameter-values to true in jboss-cli.xml.
For e.g.:-
sed -i "s/<resolve-parameter-values>false<\/resolve-parameter-values>/\
<resolve-parameter-values>true<\/resolve-parameter-values>/" \
$JBOSS_HOME/bin/jboss-cli.xml
Note that the command above is meant to be a one-off solution. From the maintenance perspective, using sed for XML is not a good idea in general. If you’re automating this, consider using XPath instead.
Note:- This functionality requires WildFly 8.0.0.CR1 or newer.
you might need to set jboss-cli.xml to <resolve-parameter-values>true<\/resolve-parameter-values>
$ sed -i "s/<resolve-parameter-values>false<\/resolve-parameter-values>/\
<resolve-parameter-values>true<\/resolve-parameter-values>/" \
$JBOSS_HOME/bin/jboss-cli.xml
src: https://mirocupak.com/using-environment-variables-in-jboss-cli/
These are good hints how to solve the problem, but the sed command does not work this way on Mac. There is a lot of fun with "-i". More information here:
sed command with -i option failing on Mac, but works on Linux
On Mac this worked for me:
sed -i "" "s/false</resolve-parameter-values>/true</resolve-parameter-values>/" $JBOSS_HOME/bin/jboss-cli.xml
Unfortunately this way of using sed does not work on RHEL for example.
BSD (Mac) grep allows for this command:
grep -n "FIXME" **/*.rb
But GNU grep forces me to specify at least a folder to start from:
grep -n "FIXME" {lib,spec}/**/*.rb
Is there a way to get this to behave like it does in BSD grep?
Switch to ack. It uses the recursive strategy by default, and comes with loads of tricky regexes for types of language files available as flags.
For instance, writing:
ack FIXME --ruby
Will search the current directory recursively for anything that may be a Ruby file. This will work the same on Mac and Linux.
I want to grep 2 patterns in a file on Solaris UNIX.
That is grep 'pattern1 OR pattern2' filename.
The following command does NOT work:
grep 'pattern1\|pattern2' filename
What is wrong with this command?
NOTE: I am on Solaris
What operating system are you on?
It will work with on systems with GNU grep, but on BSD, Solaris, etc., \| is not supported.
Try egrep or grep -E, e.g.
egrep 'pattern1|pattern2'
If you want POSIX functionality (i.e. Linux-like behavior) you can put the POSIX 2-compatible binaries at the beginning of your path:
$ echo $PATH
/usr/xpg4/bin:/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:[...]
There is also /usr/xpg6 which is POSIX 1 compatible.
/usr/bin: SVID/XPG3
/usr/xpg4/bin: POSIX.2/POSIX.2a/SUS/SUSv2/XPG4
/usr/xpg6/bin: POSIX.1-2001/SUSv3
That command works fine for me. Please add additional information such as your platform and the exact regular expression and file contents you're using (minimized to the smallest example that still reproduces the issue). (I would add a comment to your post but don't have enough reputation.)
That should be correct. Make sure that you do or don't add the appropriate spaces i.e. "pattern1\|pattern2" vs "pattern1\| pattern2".
Are you sure you aren't just having problems with cases or something? try the -i switch.
That depends entirely on what pattern1 and pattern2 are. If they're just words, it should work, otherwise you'll need:
grep '\(pattern1\)\|\(pattern2\)'
An arcane method using fgrep (ie: fixed strings) that works on Solaris 10...
Provide a pattern-list, with each pattern separated by a NEWLINE, yet quoted so as to be interpreted by the shell as one word:-
fgrep 'pattern1
pattern2' filename
This method also works for grep, fgrep and egrep in /usr/xpg4/bin, although the pipe-delimited ERE in any egrep is sometimes the least fussy.
You can insert arbitrary newlines in a string if your shell allows history-editing, eg: in bash issue C-v C-j in either emacs mode or vi-command mode.
egrep -e "string1|string2" works for me in SunOS 5.9 (Solaris)
Is it possible to configure nginx to run a unix command based on a url?
For example:
http://localhost/list/usr/local
This runs:
ls /usr/local
Then returns the results?
No, Nginx cannot.
Nginx is able to run perl scripts when it's built with perl support. And it seems that you can program enything that can be done with a plain perl.
I think you should look at this direction.
While expirementing with perl you should keep in mind that perl interpreter blocks nginx process until finished so it's not recomended to run long-lasting jobs.
BTW: Perl support still marked as experimental.
You can use Perl module for this task.
Nginx Perl module