Hello All,
I just wanted to know what are the different ways of using commands in combination.
The most common one which i know is using pipes.
Also grouping is also done like ( ls; date) where output of both the commands is displayed.
Are there any other ways of combining various... (2 Replies)
I want to show a output like this
Lee Ballancore
PID TTY TIME CMD
31799 pts/3 00:00:00 vim
31866 pts/3 00:00:00 vim
2495 pts/7 00:00:00 vim
8368 pts/0 00:00:00 vim
9544 pts/2 00:00:00 ps
Alistairr Rutherford
PID TTY TIME CMD
8368 pts/0 00:00:00 vim
9544 pts/2 00:00:00 ps
... (3 Replies)
Hi,
I am cutting data from a fixed length test file and then writing out a new record using the echo command, the problem I have is how to stop multiple spaces from being written to the output file as a single space.
Example:
cat filea | while read line
do
field1=`echo $line | cut -c1-2`
... (6 Replies)
I have a file split something like
01/11/2010:
No of users 100
02/11/2010:
No of users 102
03/11/2010:
No of users 99
...
I want to search the file for a particular date and then extract the following line with the date, something like
02/11/2010 No of users 102
I can grep... (6 Replies)
I have an awk script to find the maximum value of the 2nd column of a 2 column datafile, but I need to find the top 5 maximum values of the 2nd column.
Here is the script that works for the maximum value.
awk 'BEGIN { subjectmax=$1 ; max=0} $2 >= max {subjectmax=$1 ; max=$2} END {print... (3 Replies)
Hi,
I am getting crazy after days on looking at it:
Bash in Ubuntu 12.04.1
I want to do this:
pattern="system /path1/file1 file1"
new_pattern=" data /path2/file2 file2"
file to edit: data.db
- I need to search in the file data.db for the nth occurrence of pattern
- pattern must... (14 Replies)
I have a file1 like
prt1|als28.1 prt3|als53.1 prt2|als550.1 prt1|bls9.2 prt2|als7.2 prt2|bls0.2
prt2|als872.1 prt1|bls871.1 prt2|als6.2 prt4|als22.1 prt2|bls43.2
I want to create a file2 from this file by comparing all the possible combinations of patterns (prt) assuming prt1... (3 Replies)
Im currently running this command to satisfy a particular task. it works for my purposes. but i want to be able to optimize this string of commands and have it be reduced to 1 or 2 commands, if at all possible:
head -4 datafile 2>/dev/null | cut -c1-400 | wc | awk '{print $2$1$3}' (5 Replies)
In the awk below I am trying to remove all lines above and including the pattern Test or Test2. Each block is seperated by a newline and Test2 also appears in the lines to keep but it will always have additional text after it. The Test to remove will not. The awk executed until the || was added... (2 Replies)
Discussion started by: cmccabe
2 Replies
LEARN ABOUT DEBIAN
io::async::pid
IO::Async::PID(3pm) User Contributed Perl Documentation IO::Async::PID(3pm)NAME
"IO::Async::PID" - event callback on exit of a child process
SYNOPSIS
use IO::Async::PID;
use POSIX qw( WEXITSTATUS );
use IO::Async::Loop;
my $loop = IO::Async::Loop->new;
my $kid = $loop->fork(
code => sub {
print "Child sleeping..
";
sleep 10;
print "Child exiting
";
return 20;
},
);
print "Child process $kid started
";
my $pid = IO::Async::PID->new(
pid => $kid,
on_exit => sub {
my ( $self, $exitcode ) = @_;
printf "Child process %d exited with status %d
",
$self->pid, WEXITSTATUS($exitcode);
},
);
$loop->add( $pid );
$loop->run;
DESCRIPTION
This subclass of IO::Async::Notifier invokes its callback when a process exits.
For most use cases, a IO::Async::Process object provides more control of setting up the process, connecting filehandles to it, sending data
to and receiving data from it.
EVENTS
The following events are invoked, either using subclass methods or CODE references in parameters:
on_exit $exitcode
Invoked when the watched process exits.
PARAMETERS
The following named parameters may be passed to "new" or "configure":
pid => INT
The process ID to watch. Must be given before the object has been added to the containing "IO::Async::Loop" object.
on_exit => CODE
CODE reference for the "on_exit" event.
Once the "on_exit" continuation has been invoked, the "IO::Async::PID" object is removed from the containing "IO::Async::Loop" object.
METHODS
$process_id = $pid->pid
Returns the underlying process ID
$pid->kill( $signal )
Sends a signal to the process
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.14.2 2012-10-24 IO::Async::PID(3pm)