Hi,
I am looking for a method to get column13 to column 50 data from the 1st line of a multiline reord. The records are stored in a large file and are separated by newline. sample format is
(data in red is to be extracted)
<header>
A001dfhskhfkdsh hajfhksdhfjh... (3 Replies)
I'm working on formatting some attendance data to meet a vendors requirements to upload to their system. With some help on the forums here, I have the data close. But they've since changed what they want.
The vendor wants me to submit three fields to them. Field 1 is the studentid field,... (4 Replies)
hi all,
when i try to start an applicationserver
for an example:
./kStart.sh > out.txt
so kStart.sh script will start the application server and write the details to out.txt
but in mycase... it is writing to out.txt and as well it is showing in the prompt also...
I want only the... (2 Replies)
Hi,
I have data in following format.
10001, John, Daves, Architecture, -2219
10002, Jim, Cirners, Businessman, -2219
1003, Tom, Katch, Engineer, -14003
I want to select the last column of the above given file and paste it on a different file in the following manner.
File TEST column... (11 Replies)
The script must ask the user to enter the user name and check whether the user exists in /etc/passwd (you must allow the partial usernames also). If the username exists, display the details as:
List of users
Login Name:
User ID:
... (3 Replies)
Hi Friends,
I'm a great fan of this forum... it has helped me tone my skills in shell scripting. I have a challenge here, which I'm sure you guys would help me in achieving...
File A has a list of job ids and I need to compare this with the File B (*.log) and File C (extend *.log) and copy... (6 Replies)
I have a flatfile A.txt
date|products|notes|location
121117|a108|this is a test|florida
121118|b111|just test it|tampa
How do i write an awk to create a file name as location.txt and have products:notes
awk -F'|' '{ print $2 ":" $3 }' A.txt > $4.txt
I am sure it cannot write to... (5 Replies)
Trying to use perl to output specific fields from all text files in a directory to one new file. Each text file on a new line. The below seems to work for one text file but not more. Thank you :).
perl -ne 's/^#//; @n = (6, 7, 8, 16); print if $. ~~ @n' *.txt > out.txt
format of all text... (2 Replies)
I'm a complete beginner in UNIX (and not a computer science student either), just undergoing a tutoring course. Trying to replicate the instructions on my own I directed output of the ls listing command (lists all files of my home directory ) to My_dir.tsv file (see the screenshot) to make use of... (9 Replies)
Discussion started by: scrutinizerix
9 Replies
LEARN ABOUT DEBIAN
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 3.44 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)