Hi,
I have gps receiver log..its giving readings .like below
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
GPSD,R=1
$GPGSV,3,1,11,08,16,328,40,11,36,127,00,28,33,283,39,20,11,165,00*71... (3 Replies)
Hi,
I need to read a text file from shell script line by line and copy the feilds of each line.
Below is the complete requirement.
I've text file which contains ...
pgm1 file11 file12 file13
pgm2 file21 file22
pgm3 file31 file32 file33
I'll give input as... (4 Replies)
Hi ,
I am trying to write an shell, which reads a text file (from a location) having a list of numbers of strictly 5 digits only ex: 33144
Now my script will check :
1) that each entry is only 5 digits & numeric only, no alphabets, & its not empty.
2)then it executes a shell script called... (8 Replies)
Hi all
I have spent half a day trying to create a shell script which reads a configuration file on a line by line basis.
The idea of the file is that each will contain server information, such as IP address and various port numbers. The line could also be blank (The file is user created). Here... (1 Reply)
I have a LOG file which looks like this
Import started at: Mon Jul 23 02:13:01 EDT 2012
Initialization completed in 2.146 seconds.
--------------------------------------------------------------------------------
--
Import summary for Import item: PolicyInformation... (8 Replies)
Hi All,
Am trying to write wrapper shell/bash script on a utility tool for which i need to pass 2 files as arugment to execute utility tool.
Wraper script am trying is to do with above metion 2 files.
utility tool accepts :
a. userinfo file : which contains username
b. item file : which... (2 Replies)
Hello,
I'm works on Ubuntu server
My goal : I would like to read file line per line, but i want to started at the end of file.
Currently, I use instructions :
while read line;
do
COMMAND
done < /var/log/apache2/access.log
But, the first line, i don't want this. The file is long... (5 Replies)
i have a text file as belows, it includes 2 columns, 1st is the column name, 2nd is the file_name
data_file.txt
column_name file_name
col1 file1
col2 file2
col3 file1
col4 file1
col5 file2
now, i would like to... (4 Replies)
Discussion started by: tester111
4 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