02-04-2009
can it be done without writing files to the system?
Thanks
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hey guys,
I have just started getting into shell scripting, ive been self educating myself with it and have run into a snag.
I am trying to make a very simple addition script. The script would be passed a number of parameters (numbers) and it would add them all together. I can do this fine... (2 Replies)
Discussion started by: bert682
2 Replies
2. Shell Programming and Scripting
Im trying to write a /bin/bash script that refreshes VMware Fusion using the built in snapshot capabilities.
I am having an issue getting a variable to pass into the find argument of an "if-then" statement.
Im thinking the problem might have something to do with the working directory of the... (8 Replies)
Discussion started by: afriend
8 Replies
3. Shell Programming and Scripting
I want to instert Category:XXXXX into the 2. line
something like this should work, but I have somewhere the wrong sytanx. something with the linebreak goes wrong:
sed "2i\\${n}Category:$cat\n"
Sample:
Titel Blahh Blahh abllk sdhsd sjdhf
Blahh Blah Blahh
Blahh
Should look like... (2 Replies)
Discussion started by: lowmaster
2 Replies
4. Shell Programming and Scripting
Hi all,
I have a variable say var1 (output from somewhere, which I can't change)which store something like this:
echo $var1
name=fred
age=25
address="123 abc"
password=pass1234
how can I make the variable $name, $age, $address and $password contain the info?
I mean do this in a... (1 Reply)
Discussion started by: freddy1228
1 Replies
5. Shell Programming and Scripting
Dear all,
I have basic knowledge of Unix script and her I am trying to process variable length and variable format CSV file.
The file length will depend on the numbers of Earnings/Deductions/Direct Deposits.
And
The format will depend on whether it is Earnings/Deductions or Direct Deposits... (2 Replies)
Discussion started by: chechun
2 Replies
6. Solaris
Hello all I have an interesting problem here that I can't seem to figure out. Note this exists inside a script with the following header: m#!/usr/bin/sh
What I am trying to do is build an automounting script for USB hdd's, the idea is that the user plugs their drive in then runs the script. The... (5 Replies)
Discussion started by: striker0010
5 Replies
7. Shell Programming and Scripting
Hi,
I am trying to do the following thing
var='date'
$var
Above command substitutes date for and in turn runs the date command and i am getting the todays date value.
I am trying to do the same thing as following, but facing some problems,
unique_host_pro="sed -e ' /#/d'... (3 Replies)
Discussion started by: gvinayagam
3 Replies
8. Shell Programming and Scripting
All,
I am attempting to print the tenth ($COPY2) varaibales into one file.
But i am finding that all variables are being outputted except for $10.
Can someone help!!!!
Code Below
----------
echo $SERVER $IMAGE $IMAGEDAY $IMAGEMONTH $IMAGEYEAR $COPY1 $EXPIREDAY $EXPIREMONTH... (1 Reply)
Discussion started by: Junes
1 Replies
9. Red Hat
Hi all,
Hereby wish to have your advise for below:
Main concept is
I intend to get current directory of my script file.
This script file will be copied to /etc/init.d.
A string in this copy will be replaced with current directory value.
Below is original script file:
... (6 Replies)
Discussion started by: cielle
6 Replies
10. Shell Programming and Scripting
Hi All,
I have a file which has hundred of records with fixed number of fields. In each record there is set of 8 characters which represent the duration of that activity. I want to sum up the duration present in all the records for a report. The problem is the duration changes per record so I... (5 Replies)
Discussion started by: danish0909
5 Replies
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)