I tried enclosing in single quotes. But it doesn't work properly. Any Idea how I can fix this ?
--- Executing the script
#
-- Verifying the contents of files
# cat /tmp/ORACLE_SID_VAR
1 ---------------------> I am expecting SOFIA1
#
# cat /tmp/who.txt
oracle ---------------------> Worked as expected
#
# cat /tmp/Arg_name.txt
----------------------> null. I was expecting SOFIA
#
# cat /tmp/MYVAR2.txt
Duffy ---------------------> Worked as expected
#
I am trying to run the following code from a script file but it complains that syntax of (both instances of) grep is wrong.
When I copy and paste it to the terminal, it is OK. Any idea what the problem might be?
set i = `grep -c #define flags.h`
while ($i>20)
@ i--
my func (`cat... (4 Replies)
Howdie everyone...
I have a shell script RemoveFiles.sh
Inside this file, it only has two commands as below:
rm -f ../../reportToday/temp/*
rm -f ../../report/*
My problem is that when i execute this script, nothing happened. Files remained unremoved. I don't see any error message as it... (2 Replies)
Hi,
I have a shell script in which I need to switch to another user and execute some commands and then come back to the original user.
To make it more clear -
I have to log in as user root then 'su' to jag - execute a script called backup.sh and then logout and come back to root again..
... (1 Reply)
Dear All,
I want to switch a user inside a shell script.My current user say x and user y to whom i want to switch both have login on the same server,the one on which i want to execute my script on.
"I want to do something like this
su - y
Password should be provided in the script itself.And... (6 Replies)
Hi folks
I'm coding on Ubuntu 9.04 standard shell.
I'm writing a script that needs to generate a random number at some point of its execution.
When I do
echo $RANDOMas a command inside shell, I clearly get some randomly generated number
However when I do
i=`$RANDOM`
echo $ior even... (14 Replies)
I am writing perl script to configure Cisco device but Variables inside Net::Telnet::Cisco Module doesn't work and passed to device without resolving.
Please advise.
here is a sample of script:
use Net::Telnet::Cisco;
$device = "10.14.199.1";
($o1, $o2, $o3, $o4) = split(/\./,$device);... (5 Replies)
Hello all,
Something strange going on with a shell script I'm writing. It's trying to write a list of files that it finds in a given directory to another file. But I also have a skip list so matching files that are in that skip list should be, well uhm, skipped :)
Here's the code of my... (2 Replies)
hi,
i want to login as a different user inside a shell script and then call another shell script from that script.
how to do that?
original script : script_A.sh
so when the script_A.sh is called , i want to login as a different user and then call another shell script(script_B.sh) from... (3 Replies)
Hello
I have a shell script that is run as root. Script rins ok until the point where it have to switch to user "mqm" to run other commands. It just hangs at the point of this line in the script
su - mqm -c "dspmq"
I ran the same commands at the terminal and they run fine.
Any thoughts. (6 Replies)
Discussion started by: mo12
6 Replies
LEARN ABOUT V7
flock
FLOCK(1) User Commands FLOCK(1)NAME
flock - manage locks from shell scripts
SYNOPSIS
flock [options] file|directory command [arguments]
flock [options] file|directory -c command
flock [options] number
DESCRIPTION
This utility manages flock(2) locks from within shell scripts or from the command line.
The first and second of the above forms wrap the lock around the execution of a command, in a manner similar to su(1) or newgrp(1). They
lock 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 an open file by its file descriptor number. See the examples below for how that can be used.
OPTIONS -c, --command command
Pass a single command, without arguments, to the shell with -c.
-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.
-F, --no-fork
Do not fork before executing command. Upon execution the flock process is replaced by command which continues to hold the lock.
This option is incompatible with --close as there would otherwise be nothing left to hold the lock.
-e, -x, --exclusive
Obtain an exclusive lock, sometimes called a write lock. This is the default.
-n, --nb, --nonblock
Fail rather than wait if the lock cannot be immediately acquired. 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.
-s, --shared
Obtain a shared lock, sometimes called a read lock.
-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.
-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. The zero number of seconds is interpreted as --nonblock.
--verbose
Report how long it took to acquire the lock, or why the lock could not be obtained.
-V, --version
Display version information and exit.
-h, --help
Display help text 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, except when using either of the options -n or -w which report a failure to
acquire the lock with a return value given by the -E option, or 1 by default.
When using the command variant, and executing the child worked, then the exit status is that of the child command.
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 <https://www.kernel.org/pub/linux/utils
/util-linux/>.
util-linux July 2014 FLOCK(1)