System Shock -- & doesnt work as when i supply the location it gives an error "Execute permission denied", in other words it doesnt read it as the input to the script but a separate command itself
.
If you create a script that takes input and then executes a command and puts it in the background, it works.
Say you touch a file in /tmp named hello, then you take a file name, pass it to a find command, and put that find command in the background...
After you run the script, you hit the enter key, and you get your prompt back while the find command runs in the background. As for the error you are getting, permission denied means you don't have enough permissions to do something, but I can't tell what it is from what you posted.
Another way of doing it, would be to take the input on the command line, rather than a read command, then you can just put the whole thing in the background, like:
Hi All,
I'm trying to get this to work but when I execute it I get the following error
./ftp_upload.sh: line 78: syntax error: unexpected end of file.
This was working before I expanded the script and had the here document part directly below within a function.
Can anyone spot what I've... (5 Replies)
Hi,
I need to query Oracle database for 100 users. I have these 100 users in a file. I need a shell script which would read this User file (one user at a time) & query database.
For instance:
USER CITY
--------- ----------
A CITY_A
B CITY_B
C ... (2 Replies)
I need to run an interactive program in the background so I can grep it for specific data to use for some logic in a script.
There is no quiet or background mode on the program so I plan to redirect a document with commands in it and then to grep the output.
This is almost working, except... (1 Reply)
Hi ,
I am a newbie!!!
I want to develop a script for deleting files older than x days from multiple paths. Now I could reach upto this piece of code which deletes files older than x days from a particular path. How do I enhance it to have an input from a .txt file or a .dat file? For eg:... (12 Replies)
I have script, which need some variable from user and i use below command for this
read
this script works fine while running without background, but when i run this script in background, it ask first variable then immediately it show below error
KSH variable not found
please let me... (1 Reply)
Hi All,
i am trying to put ls -lRt command to run in the background but it fails.
i continue to get output on screen and didnt get the command prompt right after i put the command in background.
command i am using is
ls -lRt &
i am using bash.
Can someone let me know how to... (6 Replies)
Hi there,
How do I enter command to the interactive console.
I was able to do it via the first line. What if I have more lines to input into the interactive console from line 3 onwards. Is there a more easier way?
(echo -e "load openvas" ; echo -e "openvas_help") | msfconsole
... (4 Replies)
Hi All,
Suppose I have a script and inside it I want/need to put it into background. I need the script to not react to SIGHUP signals.
I tried:
#!/bin/bash
echo "" > test_disown
mypid=$$
echo "PID=$mypid"
(
kill -SIGSTOP $mypid
jobs > myjobs
#disown -h <job-spec>
#kill -SIGCONT $mypid
)... (6 Replies)
I was writing a shell script, where i need to run a command through script and then take input from user and later terminate it. i am not sure how to take input in a proper format immediately after a command.
example: below command line is used to import some data in to database (LDAP)... (3 Replies)
Hello, I want to start out by saying that I am fairly new to scripting and am looking for someone that can point me in the right direction.
Basically what I need is a way to run a interactive script that will prompt users with questions weather that be yes/no or a specific answer.. I want to be... (3 Replies)
Discussion started by: shoutcast
3 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)