We are not "on call". If someone doesn't answer your question immediately, and you have no further information to provide, wait! I didn't get here just because you bumped it.
"spawn id exp4 not open" is the message expect gives when the thing you're communicating with, telnet in this case, dies while you're trying to use it. Try telneting to that IP / port manually and see what it does.
Your shell script can probably be made far more efficient -- you don't need the help of head, tail, and cut to read and tokenize lines from a file one by one, there's a command just for that.
Hello hello, did a quick search and didn't turn up anything helpful. I've got a book I'm sure has the answers, but I don't think I'll have time to finish it before this all has to work, so here goes~ if this isn't a good place to post and someone could direct me to another forum I'd appreciate... (1 Reply)
Hi All,
I have to write one expect script to login to one system.
I am using
set timeout -1
match_max 100000
spawn ssh root@hostname
Now when I do spawn ssh to that host it send some warning message and one challenge
Challenge: 111-2345
I need to read this challenge value and has... (1 Reply)
Hi,
AIX 5.3
Trying to implement script that change oracle password. Getting following errors:
send: spawn id exp3 not open
while executing
"send "xxx\r"
Any idea? (4 Replies)
Hi everybody,
We are trying to connect to a server and to a router using an .expect script that automatically authenticate the username and password needed. The error is that we cannot connect to the server using ssh AND we cannot connect to the router using either telnet or go commands from the... (1 Reply)
Can 'spawn' script be used more than once in a given expect script ??
What I'm trying to do is, first log-into a remote server through one 'ssh' spawn com and then from there log-into another server using a secod 'ssh' spawn command. But this approach is not working... the second ssh attempt... (1 Reply)
Hi all,
I have a script that runs sftp with expect so I can login and send a file in a cronjob. I've installed this on a couple other servers and it has been fine. However, this time on this machine, it seems to be giving me an issue. It won't move past the spawn sftp command and return a... (3 Replies)
Hi All,
i am trying to ssh to a remote machine and execute certain command to remote machine through script.
i am able to ssh but after its getting hung at the promt and after pressing ctrl +d i am gettin the out put as
expect: spawn id exp5 not open
while executing
"expect "$" {... (3 Replies)
Hi All, I am having an issue with my script which I am using to get files from a remote server.
In my script I am going to server:- REMOTESERVER and directory:- /Interface/Upload, and then getting files from there to my local server directory:- /ftp/jail_nextview_LMS/home/nextview_LMS/outbox.
... (1 Reply)
Discussion started by: Hero6438
1 Replies
LEARN ABOUT CENTOS
flock
FLOCK(1) User Commands FLOCK(1)NAME
flock - manage locks from shell scripts
SYNOPSIS
flock [options] <file|directory> <command> [command args]
flock [options] <file|directory> -c <command>
flock [options] <file descriptor number>
DESCRIPTION
This utility manages flock(2) locks from within shell scripts or the command line.
The first and second forms wrap the lock around the executing a command, in a manner similar to su(1) or newgrp(1). It locks a specified
file or directory, which is created (assuming appropriate permissions), if it does not already exist. By default, if the lock cannot be
immediately acquired, flock waits until the lock is available.
The third form uses open file by file descriptor number. See examples how that can be used.
OPTIONS -s, --shared
Obtain a shared lock, sometimes called a read lock.
-x, -e, --exclusive
Obtain an exclusive lock, sometimes called a write lock. This is the default.
-u, --unlock
Drop a lock. This is usually not required, since a lock is automatically dropped when the file is closed. However, it may be
required in special cases, for example if the enclosed command group may have forked a background process which should not be hold-
ing the lock.
-n, --nb, --nonblock
Fail rather than wait if the lock cannot be immediately acquired. See the -E option for the exit code used.
-w, --wait, --timeout seconds
Fail if the lock cannot be acquired within seconds. Decimal fractional values are allowed. See the -E option for the exit code
used.
-o, --close
Close the file descriptor on which the lock is held before executing command . This is useful if command spawns a child process
which should not be holding the lock.
-E, --conflict-exit-code number
The exit code used when the -n option is in use, and the conflicting lock exists, or the -w option is in use, and the timeout is
reached. The default value is 1.
-c, --command command
Pass a single command, without arguments, to the shell with -c.
-h, --help
Print a help message.
-V, --version
Show version number and exit.
EXAMPLES
shell1> flock /tmp -c cat
shell2> flock -w .007 /tmp -c echo; /bin/echo $?
Set exclusive lock to directory /tmp and the second command will fail.
shell1> flock -s /tmp -c cat
shell2> flock -s -w .007 /tmp -c echo; /bin/echo $?
Set shared lock to directory /tmp and the second command will not fail. Notice that attempting to get exclusive lock with second
command would fail.
shell> flock -x local-lock-file echo 'a b c'
Grab the exclusive lock "local-lock-file" before running echo with 'a b c'.
(
flock -n 9 || exit 1
# ... commands executed under lock ...
) 9>/var/lock/mylockfile
The form is convenient inside shell scripts. The mode used to open the file doesn't matter to flock; using > or >> allows the lock-
file to be created if it does not already exist, however, write permission is required. Using < requires that the file already
exists but only read permission is required.
[ "${FLOCKER}" != "$0" ] && exec env FLOCKER="$0" flock -en "$0" "$0" "$@" || :
This is useful boilerplate code for shell scripts. Put it at the top of the shell script you want to lock and it'll automatically
lock itself on the first run. If the env var $FLOCKER is not set to the shell script that is being run, then execute flock and grab
an exclusive non-blocking lock (using the script itself as the lock file) before re-execing itself with the right arguments. It
also sets the FLOCKER env var to the right value so it doesn't run again.
EXIT STATUS
The command uses sysexits.h return values for everything else but an options -n or -w failures which return either the value given by the
-E option, or 1 by default.
AUTHOR
H. Peter Anvin <hpa@zytor.com>
COPYRIGHT
Copyright (C) 2003-2006 H. Peter Anvin.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICU-
LAR PURPOSE.
SEE ALSO flock(2)AVAILABILITY
The flock command is part of the util-linux package and is available from Linux Kernel Archive <ftp://ftp.kernel.org/pub/linux/utils/util-
linux/>.
util-linux September 2011 FLOCK(1)