I think the _exit(2) of the shell is sufficient, no need to explicitly unlock.
However... will you ever leave background processes ? The descriptor would be passed to them, and, depending on the exact locking mechanics the lockf(1) uses, the lock might live on until those processes exit too.
Do you ever delete the lockfile ? There's a possibility of race if so.
i want to search in the current directory all the files that contain one word for example "hello"
i want to achieve it with the grep command but not with the grep * (2 Replies)
Hi everyone,
when executing this command in unix:
echo "WM7 Fatal Alerts:", $(cat query1.txt) > a.csvIt works fine, but running this command in a shell script gives an error saying that there's a syntax error.
here is content of my script:
tdbsrvr$ vi hc.sh
"hc.sh" 22 lines, 509... (4 Replies)
I am working with a sh script on a solaris 9 zone (sol 10 host) that grabs information to build the configuration command line. the variables Build64, SSLopt, CONFIGopt, and CC are populated in the script. the script includes
CC=`which gcc`
CONFIGopt=' --prefix=/ --exec-prefix=/usr... (8 Replies)
Hi,
I have a process which can run one instance at a time. Currently we have multiple scripts trying to kickoff this process. I wanted to implement the semaphore mechanism to achieve this.
I was going through few examples. The below code seems to be reasonable solution.
... (5 Replies)
Hello,
I have been working on using "flock"/file lock to prevent two instances of a bash script from being executed. Below is a simplified version of what I have to illustrate the flock part. It works as it is set up there below however the piece I am trying to figure out is how to get it to... (2 Replies)
Hi i have a script that check pings and i use flock to so the script wont run
multipul times :
its not the whole script but this is the idea :
(
flock -x -w 3 200 || exit 1
/usr/sbin/fping -c$count -i$interval -a $hosts > $FILE1 2>&1
) 200>/var/lock/.myscript.exclusivelock
now i... (4 Replies)
Hello i am having an issue with bash script and this is the code
now=$(cat hosts1.txt | awk '{print $2;}')
while read n ;do
ssh root@$now 'useradd test1; echo -e "test1\ntest1" | passwd test1 && echo "test1 ALL=(ALL:ALL) ALL" >> /etc/sudoers'
When i execute only part with cat, it... (8 Replies)
Discussion started by: tomislav91
8 Replies
LEARN ABOUT DEBIAN
explain_flock_or_die
explain_flock_or_die(3) Library Functions Manual explain_flock_or_die(3)NAME
explain_flock_or_die - control advisory lock on open file and report errors
SYNOPSIS
#include <libexplain/flock.h>
void explain_flock_or_die(int fildes, int command);
int explain_flock_on_error(int fildes, int command))
DESCRIPTION
The explain_flock_or_die function is used to call the flock(2) system call. On failure an explanation will be printed to stderr, obtained
from the explain_flock(3) function, and then the process terminates by calling exit(EXIT_FAILURE).
The explain_flock_on_error function is used to call the flock(2) system call. On failure an explanation will be printed to stderr, obtained
from the explain_flock(3) function, but still returns to the caller.
fildes The fildes, exactly as to be passed to the flock(2) system call.
command The command, exactly as to be passed to the flock(2) system call.
RETURN VALUE
The explain_flock_or_die function only returns on success, see flock(2) for more information. On failure, prints an explanation and exits,
it does not return.
The explain_flock_on_error function always returns the value return by the wrapped flock(2) system call.
EXAMPLE
The explain_flock_or_die function is intended to be used in a fashion similar to the following example:
explain_flock_or_die(fildes, command);
SEE ALSO flock(2)
apply or remove an advisory lock on an open file
explain_flock(3)
explain flock(2) errors
exit(2) terminate the calling process
COPYRIGHT
libexplain version 0.52
Copyright (C) 2009 Peter Miller
explain_flock_or_die(3)
09-29-2016
