01-19-2006
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Dear friends,
I'm a novice Unix user and I'm trying to learn the ropes. I have a big task I have to accomplish and I'm convinced Unix can get the job done, I just haven't figured out how. I recently posted on the topic of cutting text between unique text patterns and somebody helped me a great... (24 Replies)
Discussion started by: spindoctor
24 Replies
2. Shell Programming and Scripting
Hi,
i have a line with several fields (indefinite number of - count varies) separated by colon.
Now, i need to pick each field (except the first one) and have it assigned to variable within a loop. In other words, in the first iteration of the loop, the variable must be assigned with 2nd... (2 Replies)
Discussion started by: prvnrk
2 Replies
3. Shell Programming and Scripting
Greetings,
I would like to extract records from a fixed width text file that have unique field elements.
Data is structured like this:
John A Smith NY
Mary C Jones WA
Adam J Clark PA
Mary Jones WA
Fieldname / start-end position
Firstname 1-10... (8 Replies)
Discussion started by: sitney
8 Replies
4. Shell Programming and Scripting
I need some assistance, I am writing a script in bash.
I want to do two things:
1/. I want to replace the LF at the end of the RFH Ø ¸MQSTR ¸ so I can process the file record by record using a while loop.
2/. I want to extract two fields from each record, they are identified with... (1 Reply)
Discussion started by: gugs
1 Replies
5. Shell Programming and Scripting
I am need to extract a number of values from a file, put have now clue how to do this.
The file looks like this:
# My file
Dest=87;CompatibleSystemSoftwareVersion=2.5300-;
Dest=87;ImageVersion=000061f3;SystemSoftwareVersion=2.5300;CDN=http://my.backup.com/download.txt;CDN_Timeout=30;
I... (3 Replies)
Discussion started by: MagicDude4Eva
3 Replies
6. Shell Programming and Scripting
Hi,
I need to extract last character of the field retrieved from the database using select command.
eg:
select event,text from event_data;
o/p: Event1,text1
But I need to extract only '1' from the fields...similarly '2' from Event2,text2 and '3' from Event3,text3 etc., and need to pass... (6 Replies)
Discussion started by: Rajesh Putnala
6 Replies
7. Shell Programming and Scripting
I have an input file with contents like:
203969 OrdAcctCycChg USAGE_DAEMON1
203970 OrdAcctCycChg USAGE_DAEMON2
203971 OrdAcctCycChg USAGE_DAEMON3
203972 OrdAcctCycChg USAGE_DAEMON4
I need to extract variables in first column... (51 Replies)
Discussion started by: Rajesh Putnala
51 Replies
8. Shell Programming and Scripting
Hi All,
I am writing the following Perl Scrip and need your help in Pattern matching :
I have the following Shell Script that would read line by line from the file (file_svn) and would inturn calls the Perl Script:
#!/bin/bash
perl_path="/home/dev/filter"... (2 Replies)
Discussion started by: filter
2 Replies
9. Shell Programming and Scripting
I have one file A.txt which is comma separated and I want to extract first 4 field's in a file and also I want to add one more column in output
A.txt in output for all records. A.txt should not be hard coded since I do not filename it may be any file. (1 Reply)
Discussion started by: vamsi.valiveti
1 Replies
10. UNIX for Beginners Questions & Answers
Hello All,
I have a requirement to split the input.xml file different files and i have tried using earlier examples(where i have posted in the forum), but still no luck
Here is my input.xml
<jms-system-resource>
<name>UMSJMSSystemResource</name>
... (4 Replies)
Discussion started by: Siv51427882
4 Replies
FLOCK(1) User Commands FLOCK(1)
NAME
flock - manage locks from shell scripts
SYNOPSIS
flock [-sxon] [-w timeout] lockfile [-c] command...
flock [-sxon] [-w timeout] lockdir [-c] command...
flock [-sxun] [-w timeout] fd
DESCRIPTION
This utility manages flock(2) locks from within shell scripts or the command line.
The first and second forms wraps 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.
The third form is convenient inside shell scripts, and is usually used the following manner:
(
flock -n 9 || exit 1
# ... commands executed under lock ...
) 9>/var/lock/mylockfile
The mode used to open the file doesn't matter to flock; using > or >> allows the lockfile to be created if it does not already exist, how-
ever, write permission is required; using < requires that the file already exists but only read permission is required.
By default, if the lock cannot be immediately acquired, flock waits until the lock is available.
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 (with an exit code of 1) rather than wait if the lock cannot be immediately acquired.
-w, --wait, --timeout seconds
Fail (with an exit code of 1) if the lock cannot be acquired within seconds seconds. Decimal fractional values are allowed.
-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.
-c, --command command
Pass a single command to the shell with -c.
-h, --help
Print a help message.
AUTHOR
Written by 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 ftp://ftp.kernel.org/pub/linux/utils/util-linux/.
util-linux February 2006 FLOCK(1)