Hi All,
I am trying to read data from two files and then compare them and only print the records on the screen that have a same ID.i.e TAGNO =CUSTOMERNO
For Eg
My Input Files are (a) Transaction (b) Customer detail
The data in file a is like:
TagNo Date Time Station... (0 Replies)
hi all,
I'm trying to resolve a scenario where we prompt the user to enter 1 or more disk names.
From there we would run a command on each disk which would give its location.
This would allow us to create a list of disks at location A, a list of disks at location B,....etc...
Any help... (1 Reply)
I have a file where i have files name with absolute path.
Ex: files.dat and contents are:
/root/xy/yz/zz/abc.txt
/root/xx/yy/zz/ac.txt
/root/xz/yz/zx/bc.txt
/root/xy/yz/zx/abcd.txt
now i want to create all above files(dummy files and can be 0 byte). i thought of using touch but it doesn't... (10 Replies)
Hello Everyone,
The situation is:
$ alias rm="sh abc.sh"
#abc.sh:
read input
echo "The input was: " $input
$ rm xyz.txt
should return
"The input was: xyz.txt"
Here, I want the alias "rm" to execute the file "abc.sh", where "abc.sh" should take "xyz.txt"... (1 Reply)
Hi
I used this command:
mplayer http://host/axis-cgi/mjpg/video.cgi -user root -passwd root \
-cache 1024 -fps 25.0 -nosound -vc ffh264 \
-demuxer 3 -dumpstream -dumpfile output.avi It's ok but...
Video Playing is very fast! Why? Is it a synch problem?
What parameter I have to use for... (1 Reply)
Hi,
I got a requirement to automate the process.
We have SLA files, there are some 80 SLA files comes from 1.30pm - 5.30pm.
I was asked to write a script to check for the SLA files in the load directory, if the files come then we got to send the mail to the group, if the mails doesnt come... (1 Reply)
Hello there, I am posting to seek help with a KSH script,
I am making a simple calculation program where the user can enter as many numbers as they like, I am getting their input using the read command, however I am not sure how to repeat doing this and storing the input in to new variables... (7 Replies)
Hi I'm trying to create a basic script that pauses for user input to verify a file name before generating the output.
I have numerous SSL certificate files which I am trying to determine the expiry date so what I'm trying to do is write a script so that is pauses to request the name of the .pem... (9 Replies)
Hi All,
I am really new to Linux.I am trying to write a script for creating a new directory by getting input of folder name from the user.Please help me in this regard.
#! /bin/bash
echo "Enter name of dir":$filename
mkdir -p $filename
When executing this I am getting following error
... (13 Replies)
Experts,
Need your help for this. Please support
My motive is to create seperate output file for each Input Files(File 1 and File2) in another folder say(/tmp/finaloutput)
Input files
File 1(1.1.1.1.csv)
a,b,c
43,17104773,3
45,17104234,4
File 2(2.2.2.2.csv)
a,b,c
43,17104773,1... (2 Replies)
Discussion started by: as7951
2 Replies
LEARN ABOUT OSX
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