How do we do Perl's '
$inp=<>;
to prompt user a single line, in Raku ?
As lines(); keep on prompting a user input so not work identically
Please help clarify
to prompt user a single line, in Raku ?
The prompt function does this.
my $input = prompt; # No message
my $name = prompt 'Name: '; # Or with a message
See get, which is an alias for lines(1), or something pretty close to that.
It initially surprised me how hard it is to discover in Raku resources -- doc, design doc, chat logs, etc. But I guess <> and line are so overloaded that it's not that odd after all.
I've added a comment about get's (lack of) discoverability in the doc issues queue. It would be helpful to those working on the doc if you added another comment in the same issue saying where you'd looked to get (!) an answer to your Q.
Related
I am using Python's Paramiko library to SSH a remote machine and fetch some output from command-line. I see a lot of junk printing along with the actual output. How to get rid of this?
chan1.send("ls\n")
output = chan1.recv(1024).decode("utf-8")
print(output)
[u'Last login: Wed Oct 21 18:08:53 2015 from 172.16.200.77\r', u'\x1b[2J\x1b[1;1H[local]cli#BENU>enable', u'[local]cli#BENU#Configure',
I want to eliminate, [2J\x1b[1;1H and u from the output. They are junk.
It's not a junk. These are ANSI escape codes that are normally interpreted by a terminal client to pretty print the output.
If the server is correctly configured, you get these only, when you use an interactive terminal, in other words, if you requested a pseudo terminal for the session (what you should not, if you are automating the session).
The Paramiko automatically requests the pseudo terminal, if you used the SSHClient.invoke_shell, as that is supposed to be used for implementing an interactive terminal. See also How do I start a shell without terminal emulation in Python Paramiko?
If you automate an execution of remote commands, you better use the SSHClient.exec_command, which does not allocate the pseudo terminal by default (unless you override by the get_pty=True argument).
stdin, stdout, stderr = client.exec_command('ls')
See also What is the difference between exec_command and send with invoke_shell() on Paramiko?
Or as a workaround, see How can I remove the ANSI escape sequences from a string in python.
Though that's rather a hack and might not be sufficient. You might have other problems with the interactive terminal, not only the escape sequences.
You particularly are probably not interested in the "Last login" message and command-prompt (cli#BENU>) either. You do not get these with the exec_command.
If you need to use the "shell" channel due to some specific requirements or limitations of the server, note that it is technically possible to use the "shell" channel without the pseudo terminal. But Paramiko SSHClient.invoke_shell does not allow that. Instead, you can create the "shell" channel manually. See Can I call Channel.invoke_shell() without calling Channel.get_pty() beforehand, when NOT using Channel.exec_command().
And finally the u is not a part of the actual string value (note that it's outside the quotes). It's an indication that the string value is in the Unicode encoding. You want that!
This is actually not junk. The u before the string indicates that this is a unicode string. The \x1b[2J\x1b[1;1H is an escape sequence. I don't know exactly what it is supposed to do, but it appears to clear the screen when I print it out.
To see what I mean, try this code:
for string in output:
print string
I am trying to get my CGI scripts running on my web host (which runs on FreeBSD). To debug why I keep getting the dreaded "premature end of script headers" error, their support recommended that I redirect all my output to stderr, rather than printing it. Looking up how to do this, I came across a very old RAMBO ticket about it, but it looks like it was never implemented.
Per some of the answers to this question, it seems like I should be able to do a call {echo Hello, world >&2} to achieve this, but it doesn't work.
How can I write to stderr in REBOL2?
For my CGI-specific scenario, I have a truly awful workaround. Since writing to stderr in Perl (with which I am entirely unfamiliar) is a one-liner, I'm currently calling the REBOL script from Perl and printing its output to stderr from there:
#!/usr/bin/perl
use strict;
use warnings;
use CGI;
# Note the backticks
my $the_string = `/home/public/rebol -csw test-reb.cgi`;
print STDERR $the_string;
This webpage has some suggestions http://www.liquidweb.com/kb/apache-error-premature-end-of-script-headers/
to solve your real problem. Perhaps you did not have the headers printed as first thing in your script, this must be the first thing to do. Maybe the rights are not sufficient, or the .r file type was not properly added in your .htaccess as cgi able file. Your (correct!) rebol core exe has not the correct rights. Or your script ends up in an endless loop?
Some hints to redirect errors for Rebol cgi script:
http://www.rebol.com/docs/core23/rebolcore-2.html#section-6.2
Better late than never... I've just implemented it for Rebol3 in my Rebol fork.
https://github.com/Oldes/Rebol-issues/issues/2468
The syntax will be probably changed a little bit, because I don't like that the system console port is named input, although it is not just for the input.
So far it is:
print 1 ;<- std_out
modify system/ports/input 'error on
print 2 ;<- std_err
modify system/ports/input 'error off
print 3 ;<- std_out
Okay, so I'm trying to make a program that "understands" user input and does what they tell it to do. People usually just use specific commands such as "open this file" and it only works if the user types EXACTLY that. I'm trying to give my users a little bit of leeway, so that they can type something like what they want to happen, and the computer will get the general idea. With that block of rambling aside, I've run into a problem.
set word%wordNum%=%word%
:fileExtension
set extChk= %letterNum% - 2 REM Includes the period of the extension
call set extension=%%_albaiRec:~%extChk%,4%%
::extChk is checking for a period so the program will recognize a file extension
set file=
That last line is where I get stuck...
I'm trying to use that last recorded word variable.
set var=7
set word7=Wanted text
echo %word%var%%
Sorta like that?
Add setLocal enableDelayedExpansion to the start of your script.
Then replace echo %word%var%% with echo !word%var%!.
For more information - http://ss64.com/nt/delayedexpansion.html
I have a script which interacts with user (prints some questions to stderr and gets input from stdin) and then prints some data to stdin. I want to put the output of the script to a variable in vimscript. It probably should look like this:
let a = system("./script")
The supposed behavior is that script runs, interacts with user, and after all a is assigned with its output to stdout. But instead a is assigned both with outputs to stdout and stderr, so user seed no prompts.
Could you help me fixing it?
Interactive commands are best avoided from within Vim; especially with GVIM (on Windows), a new console window pops up; you may not have a fully functional terminal, ...
Better query any needed arguments in Vimscript itself (with input(); or pass them on from a custom Vim :command), and just use the external script non-interactively, feeding it everything it needs.
What gets captured by system() (as well as :!) is controlled by the 'shellredir' option. Its usual value, >%s 2>&1 captures stdout as well as stderr. Your script needs to choose one (e.g. stdout) for its output, and the other for user interaction, and the Vimscript wrapper that invokes it must (temporarily) change the option.
:let save_shellredir = &shellredir
:set shellredir=>
:let a = system('./script') " The script should interact via stderr.
:let &shellredir = save_shellredir
Call the script within the other as,
. ./script.sh
I think this is what you meant.
I have a bad problem and I hope you can give me some ideas! :)
What I want to do:
Simply read the user argument of the Script.
What is the problem:
special characters
Let me explain:
Scriptname: testscript
if the user types testscript -f filename.txt it prints out the name. Pretty easy.
But if the user types the following, it does not work for the shell: testscript -f file(somethings)name.txt
so if there are special characters, it always throws an sh: error....
Working: it works if the user writes this: testscript -f 'filename(something).txt'
with ' '
But this is inconvenient and often people forget that they have to write it.
Does anyone have an idea what I can do?
I thought about getting the argument and then add ' and ' at the beginning and end, I am not sure if the shell error is first..
Otherwise, does anyone have an idea!?
Would it be possible to check if there is an () somewhere in the filename before allowing userinput and remove () then?
Unfortunately, there's nothing your program can really do here - the error your users are seeing comes from the shell, before your program even has a chance to execute.