Shell Programming and Scripting

Hi ,

i am new to unix i need a small clarification regarding this

Code:

sqlplus -s $USER_NAME/$PASSWD@$ORA_SID<< EOF >> SQL_CONN_LOG.log

In the above command what is the meaning of <<EOF>>
Thanks,
krishna.

<<EOF=End Of File
Read all lines to the code until it find a new EOF
http://en.wikipedia.org/wiki/Here_document

>> SQL_CONN_LOG.log append data to log file.

The opening << EOF delineates the start of a "here-document". It's not related to >>, which is a redirection to append to a file, whose name should follow >>.

A here document would be terminated with a matching EOF. EOF is arbitrary, and can be almost anything.

Code:

sqlplus .... << EOF
...
EOF
# or...
sqlplus .... << HereDoc
...
HereDoc

It's common to use an exclamation mark

Code:

sqlplus -s .... << !
...
!

because Unix programmers are lazy and EOF is two times two characters too many to type!