Does anyone know of a way to mimic the up arrow/down arrow type bash behavior within a shell script?
Say I have a scripted menu, and would like to be able to up arrow to bring up the last X number of lines of user input?
Thanks to anybody with a suggestion. :) (0 Replies)
Hi,
I use AIX (ksh) and Linux (bash) servers. I'm trying to do scripts to will run in both ksh and bash, and most of the time it works. But this time I don't get it in bash (I'm more familar in ksh).
The goal of my script if to read a "config file" (like "ini" file), and make various report.... (2 Replies)
The block below isn't a surprise:$ ls
file1 file2 file3
$ x=*
$ echo $x
file1 file2 file3
$ echo '$x'
$x
$ echo "$x"
*
$But I found this block a bit bewildering:$ echo $x'
>'
*
$I'm wondering why substitution wasn't performed on the $x, since it was unquoted (as far as I can tell).... (5 Replies)
I'm trying to understand if it's possible to create a set of variables that are numbered based on another variable (using eval) in a loop, and then call on it before the loop ends.
As an example I've written a script called question (The fist command is to show what is the contents of the... (2 Replies)
Hi all
Sorry for the basic question, but i am writing a shell script to get around a slightly flaky binary that ships with one of our servers. This particular utility randomly generates the correct information and could work first time or may work on the 12th or 100th attempt etc !.... (4 Replies)
Hi all
I am relatively new to linux (specifically red hat). I have installed Fedora 13 on my machine and started playing with the terminal when i found a very strange behavior when typing a command that is not found:
the terminal does not prompt me back. In other words, i am logged as root (or... (4 Replies)
run_xfs_fsr is a xfs filesystem maintenance script designed to run under cron. The system is a home theater personal computer running mythbuntu 10.10, and is accessed remotely for these tests. cron runs a script, (xfs_fsr.sh) at 02:30 that runs the subject script under BASH and sets the... (3 Replies)
I am trying to get my history in sync in multiple bash sections and things aren't working the way I expect.
Desired behavior, hitting esc-K in all bash sessions (same userid and machine) will use the same history.
Observed behavior: Esc-k shows the history of the current session, rather than... (8 Replies)
Hi,
In the code "for loop" has been used to search for files (command line arguments) in directories and then produce the result to the standard output. However, I want when no files are named on the command line, it should read a list of files from standard input and it should use the command... (7 Replies)
So I'm trying to pass certain json elements as env vars and use them later on in a script.
Sample json:
JSON='{
"Element1": "file-123456",
"Element2": "Name, of, company written in, a very weird way",
"Element3": "path/to/some/file.txt",
}'
(part of the) script:
for s... (5 Replies)
Discussion started by: da1
5 Replies
LEARN ABOUT DEBIAN
io::async::loop::epoll
IO::Async::Loop::Epoll(3pm) User Contributed Perl Documentation IO::Async::Loop::Epoll(3pm)NAME
IO::Async::Loop::Epoll - use "IO::Async" with "epoll" on Linux
SYNOPSIS
use IO::Async::Loop::Epoll;
use IO::Async::Stream;
use IO::Async::Signal;
my $loop = IO::Async::Loop::Epoll->new();
$loop->add( IO::Async::Stream->new(
read_handle => *STDIN,
on_read => sub {
my ( $self, $buffref ) = @_;
while( $$buffref =~ s/^(.*)
?
// ) {
print "You said: $1
";
}
},
) );
$loop->add( IO::Async::Signal->new(
name => 'INT',
on_receipt => sub {
print "SIGINT, will now quit
";
$loop->loop_stop;
},
) );
$loop->loop_forever();
DESCRIPTION
This subclass of IO::Async::Loop uses IO::Epoll to perform read-ready and write-ready tests so that the O(1) high-performance multiplexing
of Linux's epoll_pwait(2) syscall can be used.
The "epoll" Linux subsystem uses a registration system similar to the higher level IO::Poll object wrapper, meaning that better performance
can be achieved in programs using a large number of filehandles. Each epoll_pwait(2) syscall only has an overhead proportional to the
number of ready filehandles, rather than the total number being watched. For more detail, see the epoll(7) manpage.
This class uses the epoll_pwait(2) system call, which atomically switches the process's signal mask, performs a wait exactly as
epoll_wait(2) would, then switches it back. This allows a process to block the signals it cares about, but switch in an empty signal mask
during the poll, allowing it to handle file IO and signals concurrently.
CONSTRUCTOR
$loop = IO::Async::Loop::Epoll->new()
This function returns a new instance of a "IO::Async::Loop::Epoll" object.
METHODS
As this is a subclass of IO::Async::Loop, all of its methods are inherited. Expect where noted below, all of the class's methods behave
identically to "IO::Async::Loop".
$count = $loop->loop_once( $timeout )
This method calls the "poll()" method on the stored "IO::Epoll" object, passing in the value of $timeout, and processes the results of that
call. It returns the total number of "IO::Async::Notifier" callbacks invoked, or "undef" if the underlying "epoll_pwait()" method returned
an error. If the "epoll_pwait()" was interrupted by a signal, then 0 is returned instead.
SEE ALSO
o IO::Epoll - Scalable IO Multiplexing for Linux 2.5.44 and higher
o IO::Async::Loop::Poll - use IO::Async with poll(2)AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.14.2 2012-04-10 IO::Async::Loop::Epoll(3pm)