Hi,
How will you refer one variable's value using another in unix?
For e.g
Take the case
System1_ip=172.120.20.54
And in latter part of the program while I'm using the values in a for loop
I use
i=System1
j=${i}_ip
k=$j
But K's value at the end of the run is System1_ip
I want... (2 Replies)
I want to see a command that I typed a few days back. It looks like I can access only the latest 1000 commands through the history command. Is there a way I can access it or has it been deleted? (2 Replies)
I need to refer a remote(present on another unix server) directory from my unix machine as a local file.
e.g.
I have one directory D1 on 10.10.10.10 and i need to access files in this directory just like they are present on my unix machine 20.20.20.20.
Is there any way out... i read a bit... (1 Reply)
Hi
I have the following block of code in korn shell and don't now how to refer to variable `print variable1.$dvd` ?
---
integer dvd=4
integer number=0
while (( dvd!=0 ))
do
print "Iteracja numer : $dvd"
print "$_" #it refers to $dvd var but want to refer... (3 Replies)
This may be a dumb question, but googling is not giving me an answer. I'm trying to figure out how to refer to an input file in my code.
Lets say i run a script in bash:
"sh shellscript.sh inputfile"
(Inputfile will be variable...whatever file i run the script on)
I wanted to make... (5 Replies)
Hi all,
I have a script which should take more than 9 command line inputs while running. Likescript.sh a s d f g h j j k l o p i u y t r e w
Now in the script if I have to access one of the input which is at position after 9, in this case say 'p' then how can I do that?
echo $12 will not work... (15 Replies)
What does this do:
f{
local logfile=$1
] && logfile=$AMS_LOGFILE
echo -e "--"
}
Can someone please guide me what does
a) local variable do
b) -z option stands for what?
c) what other options are there (like -n, or -e, .., which man page do i refer to go through these... (6 Replies)
Hi All,
I'm having a python script: test.py in /path/to/script/test.py
I'm using a properties file: test_properties.py (it is having values as dictionary{}) which is in same DIR as the script.
Sample Properties file:
params = {
'target_db' : 'a1_db'
'src_db' : ... (15 Replies)
Discussion started by: saps19
15 Replies
LEARN ABOUT CENTOS
begin
BEGIN(7) PostgreSQL 9.2.7 Documentation BEGIN(7)NAME
BEGIN - start a transaction block
SYNOPSIS
BEGIN [ WORK | TRANSACTION ] [ transaction_mode [, ...] ]
where transaction_mode is one of:
ISOLATION LEVEL { SERIALIZABLE | REPEATABLE READ | READ COMMITTED | READ UNCOMMITTED }
READ WRITE | READ ONLY
[ NOT ] DEFERRABLE
DESCRIPTION
BEGIN initiates a transaction block, that is, all statements after a BEGIN command will be executed in a single transaction until an
explicit COMMIT(7) or ROLLBACK(7) is given. By default (without BEGIN), PostgreSQL executes transactions in "autocommit" mode, that is,
each statement is executed in its own transaction and a commit is implicitly performed at the end of the statement (if execution was
successful, otherwise a rollback is done).
Statements are executed more quickly in a transaction block, because transaction start/commit requires significant CPU and disk activity.
Execution of multiple statements inside a transaction is also useful to ensure consistency when making several related changes: other
sessions will be unable to see the intermediate states wherein not all the related updates have been done.
If the isolation level, read/write mode, or deferrable mode is specified, the new transaction has those characteristics, as if SET
TRANSACTION (SET_TRANSACTION(7)) was executed.
PARAMETERS
WORK, TRANSACTION
Optional key words. They have no effect.
Refer to SET TRANSACTION (SET_TRANSACTION(7)) for information on the meaning of the other parameters to this statement.
NOTES
START TRANSACTION (START_TRANSACTION(7)) has the same functionality as BEGIN.
Use COMMIT(7) or ROLLBACK(7) to terminate a transaction block.
Issuing BEGIN when already inside a transaction block will provoke a warning message. The state of the transaction is not affected. To nest
transactions within a transaction block, use savepoints (see SAVEPOINT(7)).
For reasons of backwards compatibility, the commas between successive transaction_modes can be omitted.
EXAMPLES
To begin a transaction block:
BEGIN;
COMPATIBILITY
BEGIN is a PostgreSQL language extension. It is equivalent to the SQL-standard command START TRANSACTION (START_TRANSACTION(7)), whose
reference page contains additional compatibility information.
The DEFERRABLE transaction_mode is a PostgreSQL language extension.
Incidentally, the BEGIN key word is used for a different purpose in embedded SQL. You are advised to be careful about the transaction
semantics when porting database applications.
SEE ALSO COMMIT(7), ROLLBACK(7), START TRANSACTION (START_TRANSACTION(7)), SAVEPOINT(7)PostgreSQL 9.2.7 2014-02-17 BEGIN(7)