This might sound stupid, but can you replace this section:
with
and give it another try? Let us know the result please.
The output is the same with that change, but thanks for trying anyway. After removing the sed filter from the original script I posted, the output looks something like:
So this means that the FIFO buffer contains several bytes instead of just one... Which is weird, because, I thought 'printf "${CHAR}" > ${MY_FIFO}"' was supposed to pause the loop execution, UNTIL FIFO was emptied by something like 'cat ${MY_FIFO}'. After cat-ing FIFO, I thought the loop would freeze again at 'printf "${CHAR}" > ${MY_FIFO}"', until another instance of 'cat ${MY_FIFO}', but, apparently it doesn't. Apparently, it just feeds FIFO a random amount of bytes... WHY???
---------- Post updated at 04:52 PM ---------- Previous update was at 04:44 PM ----------
I'm thinking, maybe, cat opens up the FIFO for a longer time than it takes the loop to iterate, so the loop iterates several times, spitting several bytes into FIFO, until cat stops reading from FIFO (that is, until FIFO's output is closed)... Does this make any sense to you? And, if that is the case: How would I prevent that from happening?
I posted a question on date intervals about a month back asking about how I could be able to go about a user entering the starting year/month/day and an ending year/month/day and then the script automatically cycling through each day of each month of each year that the user has specified.
I... (7 Replies)
In my server migration requirement, I need to compare if one file on old server is exactly the same as the corresponding file on the new server.
For diff and comm, the inputs need to be sorted. But I do not want to disturb the content of the file and need to find byte-to-byte match.
Please... (4 Replies)
Hi All
Can anyone please suggest me how to remove the last byte from a falt file .This is from the last line's last BYTE.
Please suggest me something.
Thank's and regards
Vinay (1 Reply)
divide input values into specified number (-100 or -200) according to the key (a1 or a2 ....)
For ex: if we give -100 in the command line it would create 100 number intervals (1-100, 100-200, 200-300) untill it covers the value 300 in a1.
Note: It should work the same even with huge numbers... (3 Replies)
Hi
I am new to expect. Please if any one can help on my issue its really appreciable. here is my issue:
I want expect script for random passwords and random commands generation.
please can anyone help me?
Many Thanks in advance (0 Replies)
Need to use dd to generate a large file from a sample file of random data. This is because I don't have /dev/urandom.
I create a named pipe then:
dd if=mynamed.fifo do=myfile.fifo bs=1024 count=1024
but when I cat a file to the fifo that's 1024 random bytes:
cat randomfile.txt >... (7 Replies)
There was an upload recently on generating a pseudo-random file when /dev/random does NOT exist.
This does not need /dev/random, /dev/urandom or $RANDOM either...
(I assume $RANDOM relies on the /dev/random device in some way.)
This code uses hexdump just because I like hexdump for ease of... (2 Replies)
Hi all,
I hope you can help me with the following question:
I have multiple tables like this:
Chr Start End Zygosity Gene
chr1 153233510 153233510 het LOR
chr1 153233615 153233615 hom LOR
chr1 153233701 153233701 hom LOR
chr1 ... (5 Replies)
Hello
I created 3 files by:
dd if=/dev/urandom bs=1024 count=1000000 of=./testfile1
dd if=/dev/urandom bs=1024 count=5000000 of=./testfile2
dd if=/dev/urandom bs=1024 count=10000000 of=./testfile3
Now I want to know how to make a change in a specific byte and/or line of theses files? (2 Replies)
hi all,
I wish to calculate the length between intervals whose are defined by a starting and an end possition. The data looks like this:
1 10
23 30
45 60
70 100...
The desired output should be:
13 # (23-10)
15 # (45-30)
10 # (70-60)...
I donīt know how to operate with different... (2 Replies)
Discussion started by: lsantome
2 Replies
LEARN ABOUT REDHAT
fifo
FIFO(4) Linux Programmer's Manual FIFO(4)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 non-blocking mode. In this case, opening for read only will succeed even if noone 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 non-blocking mode. POSIX leaves this behaviour 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 specially indicated in ls -l.
SEE ALSO mkfifo(3), mkfifo(1), pipe(2), socketpair(2), open(2), signal(2), sigaction(2)Linux Man Page 1999-06-20 FIFO(4)