Pipes and fifos cannot overflow.
...
With one process reading from a pipe and another writing to a pipe, they will take turns running.
In fact, this sort of mechanism works very well when having to export Oracle data when the data exceeds 2 GB and the Oracle exp utility doesn't support large filesystems.
I would like to know if the following can be done.
route output from an sql select directly to a pipe and compress it at the same time.
regards
Albert (2 Replies)
I currently stuck on a simple program that requires unix pipe. I'm have never programmed with unix pipe before, so if anyone can point me to the right different will be greatly appreciated!
I'm suppose to write a program that the parent spawns many child processes and each of the child process... (1 Reply)
Could one of you shad some light on this:
I need to split the file by determining the record count and than splitting it up into 4 files. Please note, this is not a fixed record length but rather a "|" delimited file.
I am not sure as how to handle reminder/offset for the 4th file.
For... (4 Replies)
Looking for examples/definition of what the term Pipe means in UNIX. Please provide answers and illustrations if possible or direction. Thanks!:) (5 Replies)
I am pretty new to UNIX. My client has a requirement where in a directory we have some files with somewhat similar name
like test_XX.txt, test_XY.txt, test_XZ.txt, test_ZZ.txt, test_ZY.txt, test_ZX.txt, test_YY.txt......Out of these files
few files have 0 bytes. Is there a way where we can go... (7 Replies)
I am trying to convert a txt file that includes one long string of data. The lines are separated with hex value 7C (for pipe).
I am trying to process this file using SQR (Peoplesoft) so I thought the easiest thing to do would be to replace the eol char with a CRLF in unix so I can just... (4 Replies)
EDIT: Nevermind, called a friend who is good at this stuff and he figured it out :D
Hi all,
So I'm trying to teach myself to write programs for unix in c. I am currently creating a program, and I need to pass a struct through a pipe, but I can't figure out how.
The struct I want to pass... (0 Replies)
Hi
I am new to Unix Shell scripting have a requirement where I have to replace the "unix 1 byte delimiter" with the "pipe" separator and also remove any carriage returns and line feeds if any
The Source File
4 QFH Jungle Hill 32-34 City Road London SE23 3UX
the output should be ... (3 Replies)
I have created a fifo named pipe in solaris, which writes the content of a file, line by line, into pipe as below:
$ mkfifo namepipe
$ cat books.txt
"how to write unix code"
"how to write oracle code"
$ cat books.txt >> namepipe &
I have a readpipe.sh script which reads the named... (2 Replies)
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 OPENDARWIN
pipe
PIPE(2) BSD System Calls Manual PIPE(2)NAME
pipe -- create descriptor pair for interprocess communication
SYNOPSIS
#include <unistd.h>
int
pipe(int *fildes);
DESCRIPTION
The pipe() function creates a pipe, which is an object allowing unidirectional data flow, and allocates a pair of file descriptors. The
first descriptor connects to the read end of the pipe, and the second connects to the write end, so that data written to fildes[1] appears on
(i.e., can be read from) fildes[0]. This allows the output of one program to be sent to another program: the source's standard output is set
up to be the write end of the pipe, and the sink's standard input is set up to be the read end of the pipe. The pipe itself persists until
all its associated descriptors are closed.
A pipe whose read or write end has been closed is considered widowed. Writing on such a pipe causes the writing process to receive a SIGPIPE
signal. Widowing a pipe is the only way to deliver end-of-file to a reader: after the reader consumes any buffered data, reading a widowed
pipe returns a zero count.
RETURN VALUES
On successful creation of the pipe, zero is returned. Otherwise, a value of -1 is returned and the variable errno set to indicate the error.
ERRORS
The pipe() call will fail if:
[EMFILE] Too many descriptors are active.
[ENFILE] The system file table is full.
[EFAULT] The fildes buffer is in an invalid area of the process's address space.
SEE ALSO sh(1), read(2), write(2), fork(2), socketpair(2)HISTORY
A pipe() function call appeared in Version 6 AT&T UNIX.
4th Berkeley Distribution June 4, 1993 4th Berkeley Distribution