How to create and use named pipe on linux network.ie
client - my linux machine
server - my fren's linux machine
how to communicate between these two using named pipe created in C? do u have any similar code snippet written in C??
i got one server client application,its working fine on my machine.So i want enhance that code for networking.so help in this...
For example, I have a script that writes the time to a pipe in /etc/pipe. It writes continuously in a while true loop. How long will the data in the pipe be available for reading? If I only decide to read the pipe a day later with cat /etc/pipe, will I get all the time values right from the time I started writing?
Conversely, what if my loop only wrote the time every 10 minutes. Will I be able to access everything a day later?
Finally, pretend my loop writes the time continuously (like my first example) and I read the pipe every 30 minutes. If my computer shuts down right before I read the pipe, will the pipe be empty when I reboot or will it hold all that data?
recently I had been to interview where I had a question to be answered, that what are advantages and disadvantages when desiging an application in linux.
View 1 Replies View RelatedI have two sources of internet which I want to share and balance the load on. With one source it's easy: plug it into the wireless router and Bob's your uncle. But how would you handle two sources and get load balancing? A switch? Would that really share the load?
View 4 Replies View RelatedMandriva 2009, BIND 9.5.0-P2. Named will start however I'm getting the above error as well as these:
14-Mar-2009 15:45:37.084 general: error: zone 0.in-addr.arpa/IN: loading from master file /var/lib/named/var/named/reverse/named.zero failed: file not found
14-Mar-2009 15:45:37.084 general: error: zone 0.0.127.in-addr.arpa/IN: loading from master file /var/lib/named/var/named/reverse/named.local failed: file not found
[code].....
Named shows to be running but with the errors above I know it's not running correctly. I also copied the above dir's over to /var/lib/named/var/lib/named which is where I 'believe' it's chroot'd at, though I could be wrong since I'm unfamiliar with chroot.
I've been using pipes and redirects for a long time and just realized that I don't know exactly how they are different. I just know that if you want to store the output in a file, then you use >. Otherwise most of the time you just use |. difference between pipes and redirects?
View 1 Replies View RelatedAlthough this is a basic stuff, but still i wonder.
Consider these two examples. code...
I wonder, why doesn't redirection work in first case? when to use redirect and when to use pipes? I have been Linux for a long time, but still this basic stuff baffles me.
File descriptors with pipes-Can someone help me with this three situations, what would happen?
a) a process open the same file twice and read through two file descriptors
b) a process does fork and both parent- and child-processes read parallell
c) two processes opens and read from same file.
has anyone seen this before, when running an ssh command as normal user via ssh i get results:
ssh picolo 'ls -d /var/sadm/pkg/* | egrep "Prod|Dev|UAT" |cut -d/ -f5;uname -r;grep -v "^#" /opt/Tivoli/lcf/dat/1/DMXAdaptiveFileSystem.dat'>>sshnotroot
and it creates file
more sshnotroot
Prod
5.10
[Code]...
I am using Cent OS 5.5 and i want configure DNS, but while configuring bind i am getting below error.
#/etc/init.d/named restart Stopping named: [ OK ]
Starting named:
Error in named configuration:
/etc/named.conf:57: open: /etc/named.root.hints: file not found[FAILED]
I am running opensuse 11.0 on Intel Quad computer. A month ago I have installed DNS service on it.
Since then I have a following problem - sometimes named starts eating 200% of CPU and that causes LAN to hang down. Everything goes normal after named restart.
Is there already a program that reads multiple pipes or file descriptors and writes to the standard output (not splitting lines).Like cat, but reading all files simultaneously and preserving lines.It is needed to avoid coding of select/epoll loops or using multithreading in simple programs. Like "select loop for bash".
View 1 Replies View RelatedUnder the settings for a specific zone is it possible using the 'Automatically Generate Records From Zone' option to update from two other different zones? Also, the 'Automatically Generate Records......' option, I can't seem to find where it exists in named.conf or other file. I have it checked in Yast but I can't find that option reflected in a config file - which I would assume it would have to be.... somewhere.
View 6 Replies View Relatedhow do I remove a double file like " New File" look through everything I own no explantion.
View 3 Replies View RelatedJust for information in case if it is important to start dhcpd and named: Sep 16 20:26:44 LINUX-SRV named[2417]: nss_ldap: could not search LDAP server - Server is unavailable Sep 16 20:26:44 LINUX-SRV named[2417]: nss_ldap: could not search LDAP server - Server is unavailable
Secondly Both config files in /etc/sysconfig set parameters to start in jail root but
[Code]....
i've made a big update of almost 300Mb.I'had a working DNS server.Now, when i boot the box, named works and it resolves all the clients.If i make any change (enter a new client for example) and of course i restart named (service named restart), named stop but does not start again !!!In order to get a working named, i 'm obliged to reboot the box?
View 6 Replies View RelatedI'm trying to redirect nc command output but I can't do it.
I have tried this:
And this:
But it seems doesn't work.
I need to find one RUNNING word in latest created logs.
and as soon as i will get RUNNING WORD , i have to execute another Unix Command.
I wrote following script code...
see these simple commands:
Code:
# dbus-monitor --system >> /data/eject.txt
This one works as expected ... dbus-monitor never terminates and whenever it outputs new lines, they are
[code]....
I am trying to encrypt a file on-the-fly, redirecting the output to a named pipe [fifo]. I SSH into my server and run the command:mcrypt -k key < file > named_pipethen from my laptop I try to scp it:$ scp me@server:~/dir/named_pipe d it says scp:users/home/me/dir/named_pipe: not a regular file
View 1 Replies View RelatedOne of the dedicated servers that I have does not seem to have the service 'named' functional:
root@server2 [~]# service named start
Locating /var/named/chroot//etc/named.conf failed: [FAILED]
Note that the double slashes (//) ARE part of the output as well as the long gap before [FAILED] appears. This 'named' service not being functional is not a problem which is preventing the server / the application on it from working. There are entries in /etc/resolv.conf though.
I have three machines networked to my desktop which run a bunch of simulations in parallel. As they're running, I connect to them via SSH and screen to keep an eye on the runs and look at the output. They stay usually connected for days at a time. The SSH servers and client are running Fedora 14. Yesterday one of my coworkers accidentally yanked the plug on one of the servers while it was running. When I powered it up again, I started getting some odd connection problems. I couldn't connect to it via SSH initially because I got the Remote Host Identification Changed (RSA host key changed) error. I deleted the key in .ssh/known_hosts, which allowed me to connect, but it denied my password. I then logged into that machine locally, restarted sshd, and removed .ssh/known_hosts again. Now I can log in via SSH without problems. However, the connection dies with a "Write failed: Broken pipe" error every few minutes (as opposed to the other two machines, which stay connected indefinitely).
So my questions are:
1.) why would a power loss affect the behavior of the SSH server?
2.) why do I keep getting broken pipes now?
In linux, why are folders for configuration files always named *.d?
View 1 Replies View RelatedI am trying to copy all files under directory A to directory B. All files under directory A are starting with dot, for example:
A/.a
A/.b
A/.c
which I found if I use: cp A/* B, always get error:
cp: cannot stat 'A/*': no such file or directory
It seems there is no option for cp as ls to handle entries started with dot
I installed PyQt4 using yum but when I ran python file it came up with message which says
Code:
[root@VAIO examples]# python
Python 2.6.2 (r262:71600, Aug 21 2009, 12:22:21)
[GCC 4.4.1 20090818 (Red Hat 4.4.1-6)] on linux2
[code]....
i created a script file named myscript.shi ran this by typing sh myscript.sh and i got my outputbut,when i tried to execute by typing ./myscript.sh i received permission denied errori gave permission as chmod 777 myscript.shthen i executed by typing ./myscript.sh . It worked fineso i wanted to know whether using sh and ./ with permissions are same.. ?or did it work for only this.. are there any differences
View 1 Replies View RelatedHow can I find a list of files that are named duplicates i.e. have same name but in different case that exist in the same directory?
View 7 Replies View RelatedPython version 2.6 worked fine but since updating to version 3.1 and now 3.2 I cannot get beyond this error. I have also downloaded and installed APSW v3.7.5
View 2 Replies View RelatedNamed has been working fine for months on Fedora core 14 with updates current.a few days ago it stopped working. I tried a service named restart and received the error message: stopping named: umount:/var/named/ chroot/var/named: device is busy.I tried using kill process, which did not work. However if I use kill 9 <named process>, followed by service named stop, I can then restart the service and it works for a number of hours (less than a day), then stops again and produces the error message above when I try to restart it.I can get it working again using the procedure above, but only temporarily.
View 7 Replies View RelatedWhat is a pipe? and why a file is a named pipe? I am just learning linux.
View 2 Replies View Related