what these statements means Post: 302159053

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Top Forums UNIX for Dummies Questions & Answers what these statements means Post 302159053 by frank_rizzo on Thursday 17th of January 2008 01:20:50 AM

01-17-2008

Registered User

Please try to search for the solution first. The man command is your best friend! If your not using bash it might not be in the man page but there plenty of examples on the net.

This is directly taken from the bash man page.

Code:

       ${parameter#word}
       ${parameter##word}
              The  word  is  expanded to produce a pattern just as in pathname expansion.  If the
              pattern matches the beginning of the value of parameter, then  the  result  of  the
              expansion  is  the  expanded  value of parameter with the shortest matching pattern
              (the ‘‘#’’ case) or the longest matching pattern (the  ‘‘##’’  case)  deleted.   If
              parameter  is  @  or *, the pattern removal operation is applied to each positional
              parameter in turn, and the expansion is the resultant list.   If  parameter  is  an
              array variable subscripted with @ or *, the pattern removal operation is applied to
              each member of the array in turn, and the expansion is the resultant list.

       ${parameter%word}
       ${parameter%%word}
              The word is expanded to produce a pattern just as in pathname  expansion.   If  the
              pattern  matches  a  trailing  portion of the expanded value of parameter, then the
              result of the expansion is the expanded value of parameter with the shortest match‐
              ing  pattern  (the  ‘‘%’’  case)  or the longest matching pattern (the ‘‘%%’’ case)
              deleted.  If parameter is @ or *, the pattern removal operation is applied to  each
              positional  parameter in turn, and the expansion is the resultant list.  If parame‐
              ter is an array variable subscripted with @ or *, the pattern removal operation  is
              applied  to  each  member  of the array in turn, and the expansion is the resultant
              list.

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LEARN ABOUT CENTOS

release_savepoint

RELEASE 
SAVEPOINT(7)					  PostgreSQL 9.2.7 Documentation				      RELEASE SAVEPOINT(7)

NAME

       RELEASE_SAVEPOINT - destroy a previously defined savepoint

SYNOPSIS

       RELEASE [ SAVEPOINT ] savepoint_name

DESCRIPTION

       RELEASE SAVEPOINT destroys a savepoint previously defined in the current transaction.

       Destroying a savepoint makes it unavailable as a rollback point, but it has no other user visible behavior. It does not undo the effects of
       commands executed after the savepoint was established. (To do that, see ROLLBACK TO SAVEPOINT (ROLLBACK_TO_SAVEPOINT(7)).) Destroying a
       savepoint when it is no longer needed allows the system to reclaim some resources earlier than transaction end.

       RELEASE SAVEPOINT also destroys all savepoints that were established after the named savepoint was established.

PARAMETERS

       savepoint_name
	   The name of the savepoint to destroy.

NOTES

       Specifying a savepoint name that was not previously defined is an error.

       It is not possible to release a savepoint when the transaction is in an aborted state.

       If multiple savepoints have the same name, only the one that was most recently defined is released.

EXAMPLES

       To establish and later destroy a savepoint:

	   BEGIN;
	       INSERT INTO table1 VALUES (3);
	       SAVEPOINT my_savepoint;
	       INSERT INTO table1 VALUES (4);
	       RELEASE SAVEPOINT my_savepoint;
	   COMMIT;

       The above transaction will insert both 3 and 4.

COMPATIBILITY

       This command conforms to the SQL standard. The standard specifies that the key word SAVEPOINT is mandatory, but PostgreSQL allows it to be
       omitted.

SEE ALSO

       BEGIN(7), COMMIT(7), ROLLBACK(7), ROLLBACK TO SAVEPOINT (ROLLBACK_TO_SAVEPOINT(7)), SAVEPOINT(7)

PostgreSQL 9.2.7						    2014-02-17						      RELEASE SAVEPOINT(7)