int fd=atoi(argv[1]);
//Receive string from C
len=strlen(string)+1;
if(write(fd,&len,sizeof(int))==-1){
perror("Error on writing length");
exit(EXIT_FAILURE);
}
if(write(fd,&string,len)==-1){
perror("Error on writing string");
exit(EXIT_FAILURE);
}
My problem now is reading this string in A. I was thinking to send a SIGUSR1 to A as soon as the string is written by B on the pipe and having in A something like:
I have a parent that is passing data to child A and then child A has to process it and pass to child B. I am able to pass the data to child A but am not able to pass it to child B. Child B seems to only be receiving the last data instead of the whole data.
I saw one example in a book but it uses... (1 Reply)
Hello all,
My problem is as follows:
I'm trying to wake up a select(...); using a pipe fd. This should be rather straightforward, but I cannot get it to work. Perhaps you guys could give me a few tips.
My wakeup function looks like this:
STATIC void net_trig_wr()
{
/* write a dummy... (0 Replies)
Hi All,
I am facing a vague issue while trying to make two process talk to each
other using named pipe.
read process
=========
The process which reads, basically creates FIFO using
mkfifo - ret_val = mkfifo(HALF_DUPLEX, 0666);) func.
It then opens the pipe using open func - fd =... (1 Reply)
Hi All,
I am facing a vague issue while trying to make two process talk to each
other using named pipe.
read process
=========
The process which reads, basically creates FIFO using
mkfifo - ret_val = mkfifo(HALF_DUPLEX, 0666) func.
It then opens the pipe using open func - fd = open... (2 Replies)
Hi,
I´m having a lot of problems when working with message queues, both on HP-UX Systems and Sun Solaris. When we fill a queue with a messages, the system hangs and locks everything that relies on the use of IPC resources. Anyone knows how to eliminate this problem?
Thanks,
Haroldo Teixeira (2 Replies)
Hi guys, I'm new to Linux and Unix I have just simple code . But I don't know why it doesn't work ..
But, the outputfile is Blank.. I don't understand why.. Please help me.. Thank you very much
P.S: sorry, I don't know how to edit this post clearly.. it's hard to read.. Please try.. (2 Replies)
Hi all,
Is there a situation like system assigning same ID's for semaphores and shared memory at the same time.
Ex: When I try to create 10 Shared memory objects with starting key as 0x1500 and 10 semaphore objects with starting key as 0x1234 in the same program. Assume those are not deleted... (2 Replies)
I was asked to look into a problem with a Sun Netra 440 in another department. On the server in question, the relevant 'uname -a' information is, "SunOS host1 5.9 Generic_118558-16 sun4u sparc SUNW,Netra-440". That information aside, while the other admin is logged into the ALOM, these errors are... (0 Replies)
Hi guys,
I need to know how i can ignore Pipe '|' if Pipe is coming as a column in Pipe delimited file
for eg:
file 1:
xx|yy|"xyz|zzz"|zzz|12...
using below awk command
awk 'BEGIN {FS=OFS="|" } print $3
i would get xyz
But i want as :
xyz|zzz to consider as whole column... (13 Replies)
Discussion started by: rohit_shinez
13 Replies
LEARN ABOUT CENTOS
ipc::run::io
IPC::Run::IO(3) User Contributed Perl Documentation IPC::Run::IO(3)NAME
IPC::Run::IO -- I/O channels for IPC::Run.
SYNOPSIS
NOT IMPLEMENTED YET ON Win32! Win32 does not allow select() on normal file descriptors; IPC::RUN::IO needs to use IPC::Run::Win32Helper to
do this.
use IPC::Run qw( io );
## The sense of '>' and '<' is opposite of perl's open(),
## but agrees with IPC::Run.
$io = io( "filename", '>', $recv );
$io = io( "filename", 'r', $recv );
## Append to $recv:
$io = io( "filename", '>>', $recv );
$io = io( "filename", 'ra', $recv );
$io = io( "filename", '<', $send );
$io = io( "filename", 'w', $send );
$io = io( "filename", '<<', $send );
$io = io( "filename", 'wa', $send );
## Handles / IO objects that the caller opens:
$io = io( *HANDLE, '<', $send );
$f = IO::Handle->new( ... ); # Any subclass of IO::Handle
$io = io( $f, '<', $send );
require IPC::Run::IO;
$io = IPC::Run::IO->new( ... );
## Then run(), harness(), or start():
run $io, ...;
## You can, of course, use io() or IPC::Run::IO->new() as an
## argument to run(), harness, or start():
run io( ... );
DESCRIPTION
This class and module allows filehandles and filenames to be harnessed for I/O when used IPC::Run, independent of anything else IPC::Run is
doing (except that errors & exceptions can affect all things that IPC::Run is doing).
SUBCLASSING
INCOMPATIBLE CHANGE: due to the awkwardness introduced in ripping pseudohashes out of Perl, this class no longer uses the fields pragma.
SUBROUTINES
new I think it takes >> or << along with some other data.
TODO: Needs more thorough documentation. Patches welcome.
filename
Gets/sets the filename. Returns the value after the name change, if any.
init
Does initialization required before this can be run. This includes open()ing the file, if necessary, and clearing the destination
scalar if necessary.
open
If a filename was passed in, opens it. Determines if the handle is open via fileno(). Throws an exception on error.
open_pipe
If this is a redirection IO object, this opens the pipe in a platform independent manner.
close
Closes the handle. Throws an exception on failure.
fileno
Returns the fileno of the handle. Throws an exception on failure.
mode
Returns the operator in terms of 'r', 'w', and 'a'. There is a state 'ra', unlike Perl's open(), which indicates that data read from
the handle or file will be appended to the output if the output is a scalar. This is only meaningful if the output is a scalar, it has
no effect if the output is a subroutine.
The redirection operators can be a little confusing, so here's a reference table:
> r Read from handle in to process
< w Write from process out to handle
>> ra Read from handle in to process, appending it to existing
data if the destination is a scalar.
<< wa Write from process out to handle, appending to existing
data if IPC::Run::IO opened a named file.
op Returns the operation: '<', '>', '<<', '>>'. See "mode" if you want to spell these 'r', 'w', etc.
binmode
Sets/gets whether this pipe is in binmode or not. No effect off of Win32 OSs, of course, and on Win32, no effect after the harness is
start()ed.
dir Returns the first character of $self->op. This is either "<" or ">".
poll
TODO: Needs confirmation that this is correct. Was previously undocumented.
I believe this is polling the IO for new input and then returns undef if there will never be any more input, 0 if there is none now,
but there might be in the future, and TRUE if more input was gotten.
AUTHOR
Barrie Slaymaker <barries@slaysys.com>
TODO
Implement bidirectionality.
perl v5.16.3 2012-01-16 IPC::Run::IO(3)