I just set up an ftp server with Red Hat 5.2. I am doing the work, I'm baby stepping, but it seems like every step I get stuck. Currently, I'm trying to set up a crontab job, but I'm getting the following message: /bin/sh: /usr/bin/vi: No such file or directory. I see that vi exists in /bin/vi,... (3 Replies)
Hi,
I have a developer that is trying to start a script with sh "scriptname". In the script, he is specifying #!/usr/bin/ksh as the command interpreter. For some reason sh is ignoring the #!/usr/bin/ksh. We are running Solaris 8. Does anyone have any ideas what could be causing this? Here... (3 Replies)
Hi All,
I have a shell (#!/bin/sh) with below piece of code:
if !
then
echo Staging table ABC_INT_TAB is not present in the schema >> $OUTPUT
fi
Shell is throwning below error and continue to work even after this error... (3 Replies)
we have a shell script that we are using in KSH
if ]; then
_IFS=$IFS
IFS=:
and it's failing on /bin/sh . Is there a simple way to modify it to work on both . ( not with awk)
Thanks in adv (3 Replies)
what if the difference between
#!/bin/sh
and
#!/bin/bash
I wrote a script with the second heading now when i change my heading to the first one ...the script is not executing well....im not getting the required output....any solution to this problem...or do i have to start the... (3 Replies)
Q1. I understand that /usr/local/bin means I can install/uninstall stuff in here and have any chance of messing up my original system files or effecting any other users. I created this directory myself.
But what about the directory I didn't create, namely /Users/m/bin? How is that directory... (1 Reply)
Hi Experts,
I found that the same commands(sort, du, df, find, grep etc.) exists in both dir.
What is the difference to use them?
i.e: to use xpg4/bin/grep and usr/bin/grep
My OS version is SunOS 5.10
Regards,
Saps (7 Replies)
Hi,
I am planning to install a version of Informatica on my AIX box. It requires a specific java build in pap6470_27sr2-20141101_01(SR2).
The current link for IBM 64-bit SDK for AIX®, JavaTM Technology Edition, Version 7 Release 1 has a more recent version in j7r164redist.7.1.0.75.bin.
Is... (4 Replies)
Some question about the usage of shell scripts:
1.) Are the commands of the base shell scripts a subset of bash commands?
2.) Assume I got a long, long script WITHOUT the first line.
How can I find out if the script was originally designed für "sh" or "bash"?
3.) How can I check a given... (3 Replies)
Discussion started by: pstein
3 Replies
LEARN ABOUT NETBSD
shlock
SHLOCK(1) BSD General Commands Manual SHLOCK(1)NAME
shlock -- create or verify a lock file for shell scripts
SYNOPSIS
shlock [-du] [-p PID] -f lockfile
DESCRIPTION
The shlock command can create or verify a lock file on behalf of a shell or other script program. When it attempts to create a lock file, if
one already exists, shlock verifies that it is or is not valid. If valid, shlock will exit with a non-zero exit code. If invalid, shlock
will remove the lock file, and create a new one.
shlock uses the link(2) system call to make the final target lock file, which is an atomic operation (i.e. "dot locking", so named for this
mechanism's original use for locking system mailboxes). It puts the process ID ("PID") from the command line into the requested lock file.
shlock verifies that an extant lock file is still valid by using kill(2) with a zero signal to check for the existence of the process that
holds the lock.
The -d option causes shlock to be verbose about what it is doing.
The -f argument with lockfile is always required.
The -p option with PID is given when the program is to create a lock file; when absent, shlock will simply check for the validity of the lock
file.
The -u option causes shlock to read and write the PID as a binary pid_t, instead of as ASCII, to be compatible with the locks created by
UUCP.
EXIT STATUS
A zero exit code indicates a valid lock file.
EXAMPLES
BOURNE SHELL
#!/bin/sh
lckfile=/tmp/foo.lock
if shlock -f ${lckfile} -p $$
then
# do what required the lock
rm ${lckfile}
else
echo Lock ${lckfile} already held by `cat ${lckfile}`
fi
C SHELL
#!/bin/csh -f
set lckfile=/tmp/foo.lock
shlock -f ${lckfile} -p $$
if ($status == 0) then
# do what required the lock
rm ${lckfile}
else
echo Lock ${lckfile} already held by `cat ${lckfile}`
endif
The examples assume that the file system where the lock file is to be created is writable by the user, and has space available.
HISTORY
shlock was written for the first Network News Transfer Protocol (NNTP) software distribution, released in March 1986. The algorithm was sug-
gested by Peter Honeyman, from work he did on HoneyDanBer UUCP.
AUTHORS
Erik E. Fair <fair@clock.org>
BUGS
Does not work on NFS or other network file system on different systems because the disparate systems have disjoint PID spaces.
Cannot handle the case where a lock file was not deleted, the process that created it has exited, and the system has created a new process
with the same PID as in the dead lock file. The lock file will appear to be valid even though the process is unrelated to the one that cre-
ated the lock in the first place. Always remove your lock files after you're done.
BSD June 29, 1997 BSD