I run this command to get specific nova instance.here in my case "MyProxy-VM"
nova list --name MyProxy-VM --fields id |grep MyProxy-VM |cut -f 2 -d "|"
It works fine and also bit faster
I want to list specific glance image say "Ubuntu-14.04"
glance image-list | grep Ubuntu-14.04 | awk '{print $2;}
This command takes time so i want to list specific image.
I didn't find any option for this in openstack docs.
Is there any way to do this.
You can get the same results without grep, cut, awk calls. You can use openstack command with additional command line parameters. For example:
# openstack server list --name dev -f value -c ID
# openstack image list --property name=centos7 -f value -c ID
Related
I can't figure out how to print (unix tool) versions within a BusyBox container:
$ docker run -it quay.io/quay/busybox:latest
$ awk --version
awk: unrecognized option `--version'
BusyBox v1.32.0 (2020-08-31 17:40:13 UTC) multi-call binary.
Usage: awk [OPTIONS] [AWK_PROGRAM] [FILE]...
-v VAR=VAL Set variable
-F SEP Use SEP as field separator
-f FILE Read program from FILE
-e AWK_PROGRAM
$ cut --version
cut: unrecognized option `--version'
BusyBox v1.32.0 (2020-08-31 17:40:13 UTC) multi-call binary.
Usage: cut [OPTIONS] [FILE]...
Print selected fields from each input FILE to stdout
-b LIST Output only bytes from LIST
-c LIST Output only characters from LIST
-d CHAR Use CHAR instead of tab as the field delimiter
-s Output only the lines containing delimiter
-f N Print only these fields
-n Ignored
Any suggestions? Many mulled containers are built on top of BusyBox, best I get on top of this.
Thanks
busybox is a single program which acts as one of various tools depending on what name was used to call it. As you can see in the question, it shows its version as BusyBox v1.32.0.
Check which tools are (symbolic) links to busybox. All these are the same program and therefore have the same version, so you might only need the version of busybox and a list of commands linked to it.
According to https://unix.stackexchange.com/q/15895/330217 the best way to display the version of busybox is
busybox | head -1
I currently have the following shell command which is only partially working:
svn list $myrepo/libs/ |
xargs -P 10 -L 1 -I {} echo $myrepo/libs/ {} trunk |
sed 's/ //g' |
xargs -P 20 -L 1 svn list --depth infinity |
grep .xlsx
where $myrepo corresponds to the svn server address.
The libs folder contains a number of subfolders (currently about 30 although eventually up to 100), each which contain a number of tags, branches and a trunk. I wish to get a list of xlsx files contained only within the trunk folder of each of these subfolders. The command above works fine however it only returns the relative path from $myrepo/libs/subfolder/trunk/, so I get this back:
1/2/3/file.xlsx
Because of the potentially large number of files I would have to search through, I am performing it in two parallel steps by using xargs -P (I do not have and cannot use parallels). It am also trying to do this in one command so it can be used in php/perl/etc. and avoid multiple sytem calls.
What I would like to do is concatenate the input to this part of the command:
xargs -P 20 -L 1 svn list --depth infinity
with the output from it, to give the following:
$myrepo/libs/subfolder/trunk/1/2/3/file.xlsx
Then pass this to the grep to find the xlsx files.
I appreciate any assistance that could be provided.
If I manage to correctly divine your intention, something like this might work for you.
svn list "$myrepo/libs/" |
xargs -P 20 -n 1 sh -c 'svn list -R "$0/trunk/$1" |
sed -n "s%.*\.xlsx$%$0/trunk/$1/&%p"' "$myrepo"
Briefly, we postprocess the output from the inner svn list to filter to just .xslx files and tack the full SVN path back on at the same time. This way, the processing happens where the repo path is still known.
We hack things a bit by passing in "$myrepo" as "$0" to the subordinate sh so we don't have to export this variable. The input from the outer svn list comes as $1.
(The repos I have access to have a slightly different layout so there could be a copy/paste error somewhere.)
I have a list URLs in a file called urls.txt. Each line contains 1 URL. I want to download all of the files at once using cURL. I can't seem to get the right one-liner down.
I tried:
$ cat urls.txt | xargs -0 curl -O
But that only gives me the last file in the list.
This works for me:
$ xargs -n 1 curl -O < urls.txt
I'm in FreeBSD. Your xargs may work differently.
Note that this runs sequential curls, which you may view as unnecessarily heavy. If you'd like to save some of that overhead, the following may work in bash:
$ mapfile -t urls < urls.txt
$ curl ${urls[#]/#/-O }
This saves your URL list to an array, then expands the array with options to curl to cause targets to be downloaded. The curl command can take multiple URLs and fetch all of them, recycling the existing connection (HTTP/1.1), but it needs the -O option before each one in order to download and save each target. Note that characters within some URLs ] may need to be escaped to avoid interacting with your shell.
Or if you are using a POSIX shell rather than bash:
$ curl $(printf ' -O %s' $(cat urls.txt))
This relies on printf's behaviour of repeating the format pattern to exhaust the list of data arguments; not all stand-alone printfs will do this.
Note that this non-xargs method also may bump up against system limits for very large lists of URLs. Research ARG_MAX and MAX_ARG_STRLEN if this is a concern.
A very simple solution would be the following:
If you have a file 'file.txt' like
url="http://www.google.de"
url="http://www.yahoo.de"
url="http://www.bing.de"
Then you can use curl and simply do
curl -K file.txt
And curl will call all Urls contained in your file.txt!
So if you have control over your input-file-format, maybe this is the simplest solution for you!
Or you could just do this:
cat urls.txt | xargs curl -O
You only need to use the -I parameter when you want to insert the cat output in the middle of a command.
xargs -P 10 | curl
GNU xargs -P can run multiple curl processes in parallel. E.g. to run 10 processes:
xargs -P 10 -n 1 curl -O < urls.txt
This will speed up download 10x if your maximum download speed if not reached and if the server does not throttle IPs, which is the most common scenario.
Just don't set -P too high or your RAM may be overwhelmed.
GNU parallel can achieve similar results.
The downside of those methods is that they don't use a single connection for all files, which what curl does if you pass multiple URLs to it at once as in:
curl -O out1.txt http://exmple.com/1 -O out2.txt http://exmple.com/2
as mentioned at https://serverfault.com/questions/199434/how-do-i-make-curl-use-keepalive-from-the-command-line
Maybe combining both methods would give the best results? But I imagine that parallelization is more important than keeping the connection alive.
See also: Parallel download using Curl command line utility
Here is how I do it on a Mac (OSX), but it should work equally well on other systems:
What you need is a text file that contains your links for curl
like so:
http://www.site1.com/subdirectory/file1-[01-15].jpg
http://www.site1.com/subdirectory/file2-[01-15].jpg
.
.
http://www.site1.com/subdirectory/file3287-[01-15].jpg
In this hypothetical case, the text file has 3287 lines and each line is coding for 15 pictures.
Let's say we save these links in a text file called testcurl.txt on the top level (/) of our hard drive.
Now we have to go into the terminal and enter the following command in the bash shell:
for i in "`cat /testcurl.txt`" ; do curl -O "$i" ; done
Make sure you are using back ticks (`)
Also make sure the flag (-O) is a capital O and NOT a zero
with the -O flag, the original filename will be taken
Happy downloading!
As others have rightly mentioned:
-cat urls.txt | xargs -0 curl -O
+cat urls.txt | xargs -n1 curl -O
However, this paradigm is a very bad idea, especially if all of your URLs come from the same server -- you're not only going to be spawning another curl instance, but will also be establishing a new TCP connection for each request, which is highly inefficient, and even more so with the now ubiquitous https.
Please use this instead:
-cat urls.txt | xargs -n1 curl -O
+cat urls.txt | wget -i/dev/fd/0
Or, even simpler:
-cat urls.txt | wget -i/dev/fd/0
+wget -i/dev/fd/0 < urls.txt
Simplest yet:
-wget -i/dev/fd/0 < urls.txt
+wget -iurls.txt
I would like to extract the first part of this hostname testsrv1
from testsrv1.main.corp.loc.domain.com in UNIX, within a shell script.
What command can I use? It would be anything before the first period .
Do you have the server name in a shell variable? Are you using a sh-like shell? If so,
${SERVERNAME%%.*}
will do what you want.
You can use cut:
echo "testsrv1.main.corp.loc.domain.com" | cut -d"." -f1
To build upon pilcrow's answer, no need for new variable, just use inbuilt $HOSTANME.
echo $HOSTNAME-->my.server.domain
echo ${HOSTNAME%%.*}-->my
Tested on two fairly different Linux's.
2.6.18-371.4.1.el5, GNU bash, version 3.2.25(1)-release (i386-redhat-linux-gnu)
3.4.76-65.111.amzn1.x86_64, GNU bash, version 4.1.2(1)-release (x86_64-redhat-linux-gnu)
try the -s switch:
hostname -s
I use command cut, awk, sed or bash variables
Operation
Via cut
[flying#lempstacker ~]$ echo "testsrv1.main.corp.loc.domain.com" | cut -d. -f1
testsrv1
[flying#lempstacker ~]$
Via awk
[flying#lempstacker ~]$ echo "testsrv1.main.corp.loc.domain.com" | awk -v FS='.' '{print $1}'
testsrv1
[flying#lempstacker ~]$
Via sed
[flying#lempstacker ~]$ echo "testsrv1.main.corp.loc.domain.com" | sed -r 's#([^.]*).(.*)#\1#g'
testsrv1
[flying#lempstacker ~]$
Via Bash Variables
[flying#lempstacker ~]$ hostName='testsrv1.main.corp.loc.domain.com'
[flying#lempstacker ~]$ echo ${hostName%%.*}
testsrv1
[flying#lempstacker ~]$
You could have used "uname -n" to just get the hostname only.
You can use IFS to split text by whichever token you want. For domain names, we can use the dot/period character.
#!/usr/bin/env sh
shorthost() {
# Set IFS to dot, so that we can split $# on dots instead of spaces.
local IFS='.'
# Break up arguments passed to shorthost so that each domain zone is
# a new index in an array.
zones=($#)
# Echo out our first zone
echo ${zones[0]}
}
If this is in your script then, for instance, you'll get test when you run shorthost test.example.com. You can adjust this to fit your use case, but knowing how to break the zones into the array is the big thing here, I think.
I wanted to provide this solution, because I feel like spawning another process is overkill when you can do it easily and completely within your shell with IFS. One thing to watch out for is that some users will recommend doing things like hostname -s, but that doesn't work in the BSD userland. For instance, MacOS users don't have the -s flag, I don't think.
Assuming the variable $HOSTNAME exists, so try echo ${HOSTNAME%%.*} to get the top-most part of the full-qualified hostname. Hope it helps.
If interested, the hint is from the below quoted partial /etc/bashrc on a REHL7 host:
if [ -e /etc/sysconfig/bash-prompt-screen ]; then
PROMPT_COMMAND=/etc/sysconfig/bash-prompt-screen
else
PROMPT_COMMAND='printf "\033k%s#%s:%s\033\\" "${USER}" "${HOSTNAME%%.*}" "${PWD/#$HOME/~}"'
fi
;; ... ```
I have a .bash_profile script and I can't get the following to work
alias lsls='ls -l | sort -n +4'
when I type the alias lsls
it does the sort but then posts this error message
"-bash: +4: command not found"
How do I get the alias to work with '+4'?
It works when type ls -l | sort -n +4 in the command line
I'm in OS X 10.4
Thanks for any help
bash-4.0$ ls -l | sort -n +4
sort: open failed: +4: No such file or directory
You need ls -l | sort -n -k 5, gnu sort is different from bsd sort
alias lsls='ls -l | sort -n -k 5'
Edit: updated to reflect change from 0 based indexing to 1 based indexing, thanks Matthew.
alias lsls='ls -l | sort -n +4' should work fine with the sort in OS X 10.4 (which does support that syntax).
when I type the alias lsls it does the sort but then posts this error message "-bash: +4: command not found"
Is it possible that you inserted a stray newline when editing your .bash_profile? e.g. if you ended up with something like this:
alias lsls='ls -l | sort -n
+4'
...that might explain the error message.
As an aside, you can get the same effect without piping through sort at all, using:
ls -lrS
This link discusses a very similar alias containing a pipe.
The problem may not have been the pipe, but the interesting solution was to use a function.