I use read often in scripts to filter the right part into a variable like:
$ print "abc cde efg" | read k l ; print "k=$k, l=$l"
k=, l=
This works on linux and unix versions I work with. On OSX 10.4 this
doesn't work. I found a workaround but would like to know
why the original line... (5 Replies)
I know how to read and write if i have a forked process with only one child. However what is involved with reading and writing with many forked processes. Say one parent that forks 5 children, and needs to communicate with all 5 in half duplex.
int temp, counter=0;
do{
pipe(temp);
... (5 Replies)
I have the following code which works on AIX 4.3 but fails at times on AIX 5.3
with:
cat: 0652-054 cannot write to output. There is no process to read data written to a pipe.
validator="${validator_exe} ${validator_parms}"
cmd_line="${CAT} ${data_file} | ${validator}... (6 Replies)
Hi Everyone,
The machine I'm working on is an AIX 5.3 LPAR running on a P650. oslevel -r shows 5300-08. I'm trying to take a backup to a SCSI tape drive, which has been working up until this point. I know of nothing that has changed recently to cause this problem. But when I try to take a... (0 Replies)
I have a perl program that I want to read from a file passed as an argument or from a pipe. If their is no pipe or arguments, I want it to output a help message. I am stuck on how to prevent perl from reading from the keyboard if it isn't fed any file names or data from a pipe. The only things I... (4 Replies)
We use SAP application cluster on AIX. Communication between 2 of its instances is failing randomly with the following error:
java.net.SocketException: There is no process to read data written to a pipe.
The above error causes a cluster restart if an important communication fails.
Can... (0 Replies)
I have a file data_1.out which contains:
1|abc mail|mail subject|mail body
2|def mail|mail subject|def mail body
I am trying to read the variables from data_1.out and use them to print to 2 different files based on the id (first_column)
The problem is I am not able to read the file... (8 Replies)
Hello,
I need to read the pipe data as:-
cat abc.txt | uuencode abc.txt | mailx -s hi xyz@xyz.com
I will override the mailx function so that when mailx is called, it calls my version of maix and in that function I want to read the file which is attached in progional mailx function- abc.txt... (7 Replies)
Hello,
I have an ffmpeg bash script which is working nice and
I need to do the same for other sources.
To create new scripts and to deal with multiple bash files sounds not logical. It is a bit hard to manage for me..
I wondered if it was possible to make my input file as variable.
Then I... (1 Reply)
Hi All,
I'm creating a program which reads millions of bytes from the PIPE and do some processing. As the data is more, the idea is to read the pipe parallely.
Sun Solaris 8
See the code below:
#!/bin/sh
MAXTHREAD=30
awk '{print $1}' metadata.csv > nvpipe &
while
do
... (3 Replies)
Discussion started by: mr_manii
3 Replies
LEARN ABOUT CENTOS
fifo
FIFO(7) Linux Programmer's Manual FIFO(7)NAME
fifo - first-in first-out special file, named pipe
DESCRIPTION
A FIFO special file (a named pipe) is similar to a pipe, except that it is accessed as part of the file system. It can be opened by multi-
ple processes for reading or writing. When processes are exchanging data via the FIFO, the kernel passes all data internally without writ-
ing it to the file system. Thus, the FIFO special file has no contents on the file system; the file system entry merely serves as a refer-
ence point so that processes can access the pipe using a name in the file system.
The kernel maintains exactly one pipe object for each FIFO special file that is opened by at least one process. The FIFO must be opened on
both ends (reading and writing) before data can be passed. Normally, opening the FIFO blocks until the other end is opened also.
A process can open a FIFO in nonblocking mode. In this case, opening for read-only will succeed even if no-one has opened on the write
side yet, opening for write-only will fail with ENXIO (no such device or address) unless the other end has already been opened.
Under Linux, opening a FIFO for read and write will succeed both in blocking and nonblocking mode. POSIX leaves this behavior undefined.
This can be used to open a FIFO for writing while there are no readers available. A process that uses both ends of the connection in order
to communicate with itself should be very careful to avoid deadlocks.
NOTES
When a process tries to write to a FIFO that is not opened for read on the other side, the process is sent a SIGPIPE signal.
FIFO special files can be created by mkfifo(3), and are indicated by ls -l with the file type 'p'.
SEE ALSO mkfifo(1), open(2), pipe(2), sigaction(2), signal(2), socketpair(2), mkfifo(3), pipe(7)COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2008-12-03 FIFO(7)