filename represents each element in the list returned by $(ls). I will say now that for is not the right way to do this task.
Each word output by ls is assigned into filename variable. That is the name you gave on the for line. The reason for is bad is because a filename with a space will actually be treated as two words because of "word splitting", but let's continue anyway...
filename can be any variable name. $(ls) can be replaced by any list. for example:
This is a proper list. If you want a properly split list of files, use a glob:
We can leave out the parameter expansion to get the extension and just do that logic in the case patterns.
#!/bin/bash
for file in $HOME/*;
do
if ; then
rm -i $file > /dev/null
echo "$?"
echo "$file has been deleted"
fi
done
Been trying to learn shell scripting for a week or so now, when i run the script it doesnt display an error message, seems like it runs fine, however it doesnt delete... (10 Replies)
Hi below is my script
for((i=0;i<=$TOTAL;i++))
do
echo "IP's created are $s1.$s2.$s3.$s4"
s4=`expr $s4 + 1`
done
where s1,2,3,4 are input varibles
below error occurs while running the script
syntax error at lin 11: '(' unexpected
... (12 Replies)
Guys - I am new to Unix scripting and am in need for a script that does the following. I have bits and pieces created and tested but i am just having a little difficult time getting it all together.
- Loop through till it finds a string in a specific file.
Any help is greatly appreciated.
... (1 Reply)
Hi,
I have a doubt in usage of while loop in Shell script as Iam new to this.
My requirement is that,I have two different directories containing some files which move files to other folder after parsing is done.
In my script i wanted to add a while loop which checks for the count in these two... (5 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,
I'm using Ksh and I'm seeing some of code in my programme as given below.
Could you please let me know whats is this meeaing ?
(I'm new to this unix)
grep "1034" /u/kkk/bin/temp5.lst|cut -c1-2 >/u/kkk/bin/temp6.lst
if
then
echo ""
... (2 Replies)
hi i was wondering if someone can help me with a while loop..i have been looking at this for hours and dont no wut to do..
i have to make a menu style.. to have a beeter understanding i have linked a photo at the bottom...
http://www.mypicx.com/uploadimg/772204432_08022011_1.pngand then
... (1 Reply)
hi.. this is shell scripting lab15.sh
i dont understand this lab i am at the screen shot part. i was wondering if someone can take a quick look at this lab i have linked the doc below. i dont know where to start
i have did the
Required Errorlevels
Errorlevel # but dont... (1 Reply)
Hi there again,
I need some help in figuring out how to execute a for loop command to come up with my desired output. I have individual monthly files and a single file containing a list of location data for 1 year. I want to do a loop where for each monthly file say Jan.hdf, if will read the... (8 Replies)
I am trying to create an Expect script that does the following:
1) Telnets to an IP address and logs in with user ID and Password
2) Issue a CLI command to the server that will output data of which I am particularly interested in a DS1 clock 'Slips' value. I want to be able to keep issuing... (0 Replies)
Discussion started by: dwightlaidler
0 Replies
LEARN ABOUT DEBIAN
anyevent::loop
AnyEvent::Loop(3pm) User Contributed Perl Documentation AnyEvent::Loop(3pm)NAME
AnyEvent::Loop - AnyEvent's Pure-Perl event loop
SYNOPSIS
use AnyEvent;
# use AnyEvent::Loop;
# this module gets loaded automatically when no other loop can be found
# Explicit use:
use AnyEvent::Loop;
use AnyEvent;
...
AnyEvent::Loop::run; # run the event loop
DESCRIPTION
This module provides an event loop for AnyEvent in case no other event loop could be found or loaded. You don't have to do anything to make
it work with AnyEvent except by possibly loading it before creating the first AnyEvent watcher.
This module is not some loop abstracion used by AnyEvent, but just another event loop like EV or Glib, just written in pure perl and
delivered with AnyEvent, so AnyEvent always works, even in the absence of any other backend.
If you want to use this module instead of autoloading a potentially better event loop you can simply load it (and no other event loops)
before creating the first watcher.
As for performance, this module is on par with (and usually faster than) most select/poll-based C event modules such as Event or Glib (it
does not even come close to EV, though), with respect to I/O watchers. Timers are handled less optimally, but for many common tasks, it is
still on par with event loops written in C.
This event loop has been optimised for the following use cases:
monotonic clock is available
This module will use the POSIX monotonic clock option (if it can be detected at runtime) or the POSIX "times" function (if the
resolution is at least 100Hz), in which case it will not suffer adversely from time jumps.
If no monotonic clock is available, this module will not attempt to correct for time jumps in any way.
The clock chosen will be reported if the environment variable $PERL_ANYEVENT_VERBOSE is set to 8 or higher.
any number of watchers on one fd
Supporting a large number of watchers per fd is purely a dirty benchmark optimisation not relevant in practise. The more common case of
having one watcher per fd/poll combo is special-cased, however, and therefore fast, too.
relatively few active fds per "select" call
This module expects that only a tiny amount of fds is active at any one time. This is relatively typical of larger servers (but not the
case where "select" traditionally is fast), at the expense of the "dense activity case" where most of the fds are active (which suits
"select").
The optimal implementation of the "dense" case is not much faster, though, so the module should behave very well in most cases, subject
to the bad scalability of "select" in the presence of a large number of inactive file descriptors.
lots of timer changes/iteration, or none at all
This module sorts the timer list using perl's "sort", even though a total ordering is not required for timers internally.
This sorting is expensive, but means sorting can be avoided unless the timer list has changed in a way that requires a new sort.
This means that adding lots of timers is very efficient, as well as not changing the timers. Advancing timers (e.g. recreating a
timeout watcher on activity) is also relatively efficient, for example, if you have a large number of timeout watchers that time out
after 10 seconds, then the timer list will be sorted only once every 10 seconds.
This should not have much of an impact unless you have hundreds or thousands of timers, though, or your timers have very small
timeouts.
FUNCTIONS
The only user-visible functions provided by this module loop related - watchers are created via the normal AnyEvent mechanisms.
AnyEvent::Loop::run
Run the event loop, usually the last thing done in the main program when you want to use the pure-perl backend.
AnyEvent::Loop::one_event
Blocks until at least one new event has been received by the operating system, whether or not it was AnyEvent-related.
SEE ALSO
AnyEvent.
AUTHOR
Marc Lehmann <schmorp@schmorp.de>
http://anyevent.schmorp.de
perl v5.14.2 2012-04-08 AnyEvent::Loop(3pm)