Solved

KSH scripting question

Posted on 2013-06-12
7
241 Views
Last Modified: 2013-06-12
I am looking over the ksh script and there is a line

sqlplus "/ as sysdba" <<!


I was wondering what is <<! part of it? What does it do?

I know that >> appends output to a file and that < is a standard input, but what about << in a conjunction with !
0
Comment
Question by:YZlat
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
7 Comments
 
LVL 31

Accepted Solution

by:
farzanj earned 250 total points
ID: 39241157
Just processes output until it sees ! in a line.

So it will process all lines below this command until it sees !

command << END_TAG
abc
def
adf
END_TAG

Your end tag is !
0
 
LVL 35

Author Comment

by:YZlat
ID: 39241215
I see. But there isn't any ! anywhere in my script
0
 
LVL 23

Expert Comment

by:nemws1
ID: 39241241
farzanj is 100% correct.  Just tested this on my box with ksh:

$cat <<!
> what
> is 
> up
> man
> !
what
is
up
man
$

Open in new window

0
Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

 
LVL 5

Expert Comment

by:DOSLover
ID: 39241248
This says the input begins after the next new line and continues until there is a line containing only the delimiter. In your case the delimiter is !

Here is a link that might help: http://pic.dhe.ibm.com/infocenter/aix/v7r1/index.jsp?topic=%2Fcom.ibm.aix.baseadmn%2Fdoc%2Fbaseadmndita%2Fkorn_shell_inout_redir.htm
0
 
LVL 84

Expert Comment

by:ozo
ID: 39241257
if there is no terminating ! then ksh may just read to the end of the script
0
 
LVL 23

Expert Comment

by:nemws1
ID: 39241307
ozo is correct.  bash prints out an error, ksh does not and happily accepts an end-of-file terminator:

$cat <<!
> hey
> there
> man
^Dhey
there
man
$
0
 
LVL 35

Author Closing Comment

by:YZlat
ID: 39241327
Thanks, got it!
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

The following is a collection of cases for strange behaviour when using advanced techniques in DOS batch files. You should have some basic experience in batch "programming", as I'm assuming some knowledge and not further explain the basics. For some…
Active Directory replication delay is the cause to many problems.  Here is a super easy script to force Active Directory replication to all sites with by using an elevated PowerShell command prompt, and a tool to verify your changes.
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
In a recent question (https://www.experts-exchange.com/questions/29004105/Run-AutoHotkey-script-directly-from-Notepad.html) here at Experts Exchange, a member asked how to run an AutoHotkey script (.AHK) directly from Notepad++ (aka NPP). This video…

707 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question