The reason is when you pipe the file to a while loop, it actually gets executed in a sub-shell:-
So the scope of the variable sum value is within the while loop. This is the reason why it prints 0 outside the while loop
Can I use the read command to read the contents of a variable? I'm trying by using the following code and getting nothing back. I'm in a Linux environment.
#!/bin/ksh
IFS=~
VAR1=1~2~3~4
echo $VAR1 | read a b c d
print "$a $b $c $d" (9 Replies)
# include <stdio.h>
# include <fcntl.h>
# include <stdlib.h>
# include <sys/stat.h>
int main(int argc, char *argv)
{
int fRead, fPadded, padVal;
int btRead;
int BUFFSIZE = 512;
char buff;
if (argc != 4)
{
printf ("Please provide all of the... (3 Replies)
Hi the following c-code utilizing the 'read()' man 2 read method cant read in files larger that 2gig.
Hi I've found a strange problem on ubuntu64bit, that limits the data you are allowed to allocate on a 64bit platform using the c function 'read()'
The following program wont allow to allocate... (14 Replies)
Hi Guys,
Happy New Year to you all!
I have a requirement to read an embedded new-line using KSH's read builtin.
Here is what I am trying to do:
run_sql "select guestid, address, email from guest" | while read id addr email
do
## Biz logic goes here
done
I can take care of any... (6 Replies)
hi,
this is my script #!/bin/ksh
cat temp_file.dat | while read line
do
read test
if ]; then
break
else echo "ERROR"
fi
done
when i execute this code , the script does wait for the user input . it directly prints "ERROR" and terminates after the no. of times as there... (3 Replies)
Hello All,
i am a newbie and need some help when reading a csv file in a bourne shell script. I want to read 10 lines, then wait for a minute and then do a reading of another 10 lines and so on in the same way. I want to do this till the end of file.
Any inputs are appreciated
... (3 Replies)
Hi
i am looking a way to look at a log file(log.txt) from the last time I've read it.
However after some days the main log file(log.txt) is rename to (log.txt.1).
So now i will have two log files as below.
log.txt.1
log.txt
Now, i have to read the log from the point where i have left... (3 Replies)
Hi
I am new to writing script and want to use a Bash Piped while-read and read from user input.
if something happens on server.log then do while loop or if something happend on user input then do while loop.
Pseudocode something like:
tail -n 3 -f server.log | while read serverline || read... (8 Replies)
Hi,
I am facing issues with the below:
I have a lookup file say lookup.lkp.This lookup.lkp file contains strings delimited by comma(,).
Now i want to read this command from file and execute it.
So my code below is :
Contents in the lookup.lkp file is :
c_e,m,a,`cd $BOX | ls cef_*|tail... (7 Replies)
Hi.
How can I create a history function? (By "read" command or so)
&
How can I configure a read command so that the arrow keys are not displayed so funny? (^[[A)
Thanks in advance. (4 Replies)
Discussion started by: sinnlosername
4 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)