I have a question about the commandline arguments in Perl. I'm not sure if someone has asked this question before because I'm not sure what to search for.
I'm having an aaplication where I pass some commandline arguments. But I want it to look like this: stepanalyzer --file=glasses.STEP --get=#62296,#3,#883
so I can say --get for example. And how I can pass multiple arguments with the --get
I hope someone is able to help me. Thanks in advance!
The library to use is Getopt::Long
As I said I needed something like --get="616","718"
So with this library you can put: GetOptions('file=s' => \$file, 'get=s' => \#ary);
'file=s'
Means: --file needs a string after it.
'get=s'
Means: The same, where now we can have multiple --get value on the command line and each such option adds its string to #ary. Thus the option as a comma-separated list, requested in the question, is one element in the array and one way to expand this is
#ary = split(/,/, join(',', #ary));
as shown in documentation
But there is also another way to give this: 'get=s#'. What you prefer.
Related
I'm using RRDs::Simple function and it needs bunch of parameters.
I have placed these parameters in a special variable (parsing, sorting and calculating data from a file) with all quotes, commas and other stuff.
Of course
RRDs::create ($variable);
doesn't work.
I've glanced through all perl special variables and have found nothing.
How to substitute name of variable for the data that contained in that variable?
At least could you tell me with what kind of tools(maybe another special variables) it can be done?
Assuming I'm understanding what you're asking:
You've build the 'create' data in $variable, and are now trying to use RRDs::create to actually do it?
First step is:
print $variable,"\n"; - to see what is actually there. You should be able to use this from the command line, with rrdtool create. (Which needs a filename, timestep, and some valid DS and RRA parameters)
usually, I'll use an array to pass into RRDs::create:
RRDs::create ( "test.rrd", "-s 300",
"DS:name:GAUGE:600:U:U", )
etc.
If $variable contains this information already, then that should be ok. The way to tell what went wrong is:
if ( RRDs::error ) { print RRDs::error,"\n"; }
It's possible that creating the file is the problem, or that your RRD definitions are invalid for some reason. rrdtool create on command line will tell you, as will RRDs::error;
I've been searching all over the place and since I'm taking my first steps in PERL this might be one of he dumbest questions but here it goes.
So I'm creating a script to manage my windows and later bind it to keyboard shortcuts, so I I'm trying to run a command and passing some variables:
my $command = `wmctrl -r :ACTIVE: -e 0,0,0,$monitors->{1}->{'width'}/2,$monitors->{1}->{'height'}`;
But I get an error saying I'm not passing the right parameters to the command, but if I do this, everything works great:
my $test = $monitors->{1}->{'width'}/2;
my $command = `wmctrl -r :ACTIVE: -e 0,0,0,$test,$monitors->{1}->{'height'}`;
So do I really have to do this? assign it first to a variable and then pass it, or there's a more elegant way of doing it?
The backticks operator (or the qx{}) accepts A string which is (possibly) interpolated. So accepts string and not expression like $var/2.
Thats mean than the $variables ($var->{1}->{some} too) are expanded but not the arithmetic expressions.
Therefore your 2 step variant works, but not the first.
If you want evaluate an expression inside the string you can use the next:
my $ans=42;
print "The #{[ $ans/2 ]} is only the half of answer\n";
prints
The 21 is only the half of answer
but it is not very readable, so better and elegant is what you're already doing - calculate the command argument in andvace, and to the qx{} or backticks only pass the calculated $variables.
I have an array that have some symbols that I want to remove and even thought I find a solution, I will like to know if this is the right way because I'm afraid if I use it with array will remove the character that I might need on future arrays.
Here is an example item on my array:
$string1='22 | logging monitor informational';
so I try the following:
$string1=~ s/\s{6}\|(?=\s{6})//;
So my output is:
22 logging monitor informational
Is the other way that best match "|". I just want to remove the pipe character.
Thanks in advance
"I want to remove just the pipe character."
OK, then do this:
$string1 =~ s/\|//;
This will remove the first pipe character in the string. (You said in another comment that you don't want to remove any additional pipe characters.) If that's not what you want, then I'd suggest telling us exactly what you do want. We can't read minds, you know.
In the mean time, I'd also strongly recommend reading the Perl regular expressions tutorial.
I need a module to accept the following timestamp from command line in Perl.
2010/11/29 09:39:57
I have used the Getopt::Long module to accept the command line options. But it doesn't accept the full
timestamp from command line. It is accepting only date value(2010/11/29) not accepting the time value(09:39:57).
If anyone know the module to solve this issue, kindly let me know.
Thanks in advance.
Just put quotes around the timestamp. It should work fine with Getopt::Long
./script.pl -t '2010/11/29 09:39:57'
If you want them to be separate arguments, you could do something like this:
GetOptions('date=s{2}' => \#date);
my ($day, $time) = #date;
I am trying to create my first zsh completion script, in this case for the command netcfg.
Lame as it may sound I have stuck on the first hurdle, disclaimer, I know how to do this crudely, however I seek the "ZSH WAY" to do this.
I need to list the files in /etc/networking but only the files, not the directory component, so I do the following.
echo $(ls /etc/network.d/*(.))
/etc/network.d/ethernet-dhcp /etc/network.d/wireless-wpa-config
What I wanted was:
ethernet-dhcp wireless-wpa-config
So I try (excuse my naivity) :
echo ${(s/*\/)$(ls /etc/network.d/*(.))}
/etc/network.d/ethernet-dhcp /etc/network.d/wireless-wpa-config
It seems that this doesn't work, I'm sure there must be some clever way of doing this by splitting into an array and getting the last part but as I say, I'm complete noob at this.
Any advice gratefully received.
General note: There is no need to use ls to generate the filenames. You might as well use echo some*glob. But if you want to protect the possible embedded newline characters even that is a bad idea. The first example below globs directly into an array to protect embedded newlines. The second one uses printf to generate NUL terminated data to accomplish the same thing without using a variable.
It is easy to do if you are willing to use a variable:
typeset -a entries
entries=(/etc/network.d/*(.)) # generate the list
echo ${entries#/etc/network.d/} # strip the prefix from each one
You can also do it without a variable, but the extra stuff to isolate individual entries is a bit ugly:
# From the inside, to the outside:
# * glob the entries
# * NUL terminate them into a single string
# * split at NUL
# * strip the prefix from each one
echo ${${(0)"$(printf '%s\0' /etc/network.d/*(.))"}#/etc/network.d/}
Or, if you are going to use a subshell anyway (i.e. the command substitution in the previous example), just cd to the directory so it is not part of the glob expansion (plus, you do not have to repeat the directory name):
echo ${(0)"$(cd /etc/network.d && printf '%s\0' *(.))"}
Chris Johnsen's answer is full of useful information about zsh, however it doesn't mention the much simpler solution that works in this particular case:
echo /etc/network.d/*(:t)
This is using the t history modifier as a glob qualifier.
Thanks for your suggestions guys, having done yet more reading of ZSH and coming back to the problem a couple of days later, I think I've got a very terse solution which I would like to share for your benefit.
echo ${$(print /etc/network.d/*(.)):t}
I'm used to seeing basename(1) stripping off directory components; also, you can use echo /etc/network/* to get the file listing without running the external ls program. (Running external programs can slow down completion more than you'd like; I didn't find a zsh-builtin for basename, but that doesn't mean that there isn't one.)
Here's something I hope will help:
haig% for f in /etc/network/* ; do basename $f ; done
if-down.d
if-post-down.d
if-pre-up.d
if-up.d
interfaces