CREATE or replace FUNCTION test() RETURNS boolean AS $$
$filename = '/home/postgres';
if (-e $filename) {
exec /home/postgres/test.sh &
return true; }
return false;
$$ LANGUAGE plperlu;
exec /home/postgres/test.sh & its showing syntax error.
Could you please help how to call bash script into postgres funtion/procedure
Presumably, the code needs to be syntactically valid Perl. So you'll need to clean up a few bits.
CREATE or replace FUNCTION test() RETURNS boolean AS $$
my $filename = '/home/postgres';
if (-e $filename) {
system '/home/postgres/test.sh' and return 1;
}
return;
$$ LANGUAGE plperlu;
I've changed a few things:
I declare the variable $filename using my
I used system instead of exec. exec replaces the current process - effectively never returning to the calling function
system expects to be passed a string. So I've added quotes around the command
and is usually better in flow control statements than && (and always much better than & which is for bit-flipping, not flow control)
Perl doesn't have true and false, so I've replaced true with 1 (which is a true value in Perl). And I've removed the false from the other return statement - the default behaviour of return is to return a false value
I don't have a Postgresql installation to test this on. If it still doesn't work, please tell us what errors you get.
pl/sh exists, and can be used as a procedual language.
https://github.com/petere/plsh
Related
I have a script with many other scripts sourced. Each script sourced have a function.
One of my function need to stop according to a if statement. I tried continue, break, throw, evrything I saw on internet but either my main script completely end or my function continue.
Function code:
function AutoIndus-DeployUser($path){
$yaml=Get-Content $path | ?{!$_.StartsWith("#")}
$UsersPwd=$false
$user="";$password="";$groups="";$description=""; $options=""
$yaml | %{
if (($_-match "}") -and ($UsersPwd -eq $true)){Write-Host "function should stop"; return}
*actions*
}
}
Main script:
#functions list and link to extern scripts
Get-ChildItem -Path $PSScriptRoot\functions\ | %{$script=$_.Name; . $PSScriptRoot\functions\$script}
myfunction-doesnotwork
*some code*
Edit: I saw that return should stop the function without stoping the rest of the script, unfortunatly it does not stop anything at all:
Output:
Config file found
---
Changing user _usr-dba password
Changing user _usr-dba2 password
function should stop
Changing user _usr-dba3 password
function should stop
function should stop
function should stop
function should stop
function should stop
Disabling user DisableAccounts:{
Disable-LocalUser : User DisableAccounts:{ was not found.
At C:\Scripts\AWL-MS-AUTOMATION_AND_TOOLS\functions\AutoIndus-DisableAccount.ps1:25 char:13
+ Disable-LocalUser -Name $disable
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : ObjectNotFound: (DisableAccounts:{:String) [Disable-LocalUser], UserNotFoundException
+ FullyQualifiedErrorId : UserNotFound,Microsoft.PowerShell.Commands.DisableLocalUserCommand
Disabling user _usr-dba
To help you understanding, my script read a file and do actions according to each line it is reading. It start acting when it encounter something like User{ and should stop when it encounter }, _usr-dba3 being out of the curvy brackets it should not be treated. This way all my other function use the same one file. (changing user password and diasabling user are two different functions/sourced scripts)
Like you can see return does not do its job, maybe I'm missing one point in the use of return but I don't get it right now.
To prematurely exit out of a function before you reach the end of it, use
return
it works like break to where it will stop execution but instead of stopping the whole thread it will return back to the line below where you called the function.
Also keep in mind if your function has an output set return will return it back, for example with the function below:
function Get-ReturnValue()
{
$returnValue = "this is my output"
return $returnValue
}
if you called it like this:
$receivedReturnValue = Get-ReturnValue
then the variable receivedReturnValue would be loaded with the output of the function.
I needed a fast solution so I changed my functions, now there is no return/continue/... but a value that turn true. It is initialized to false and the action on each yaml lines are done when the value is equal to false.
Edit: So finally the issue was I didn't used function correctly. Return only works if you return into another function. So I putted almost the entire sctipt into a function that calls the function AutoIndus-DeployUser. Now it works perfectly !
In SQL I learned to check for errors in every query that my script executes.
$query = "SELECT * FROM something";
$result=msqli_query($conn, $query);
if(!$result){
echo "There is something wrong with ", $query;
} else {
//Proceed as normal
}
So I figured it might be a good idea to implement the same idea into my pascal program as well. But I don't know how to check for if a part in the program fails to execute or not. I was thinking of something like this
if (//a function/procedure could not execute) then
WriteLn('Error!')
else
//Proceed with other functions/procedures;
In SQL, !$result means mysqli_query returned false because it couldn't execute the query, but I don't know how to do that to pascal functions/procedures...Normally if a function or procedure fails to execute the program will just crash with an error in the terminal, it won't return a false value like in SQL for me to catch and manipulate.
I want to make use of functions to get the full path and directory name of a script.
For this I made two functions :
function _jb-get-script-path ()
{
#returns full path to current working directory
# + path to the script + name of the script file
return $PWD/${0#./*}
}
function _jb-get-script-dirname ()
{
return ${(_jb-get-script-path)##*/}
}
as $(_jb-get-script-path) should be replaced by the result of the function called.
However, I get an error: ${(_jb-get-script-path)##*/}: bad substitution
therefore i tried another way :
function _jb-get-script-path ()
{
return $PWD/${0#./*}
}
function _jb-get-script-dirname ()
{
local temp=$(_jb-get-script-path);
return ${temp##*/}
}
but in this case, the first functions causes an error : numeric argument required. I tried to run local temp=$(_jb-get-script-path $0) in case the $0 wasn't provided through function call (or i don't really know why) but it didn't change anything
I don't want to copy the content of the second fonction as i don't want to replicate code for no good reason.
If you know why those errors happen, I really would like to know why, and of course, if you have a better solution, i'd gladely hear it. But I'm really interessed in the resolution of this problem.
You need to use echo instead of return which is used for returning a numeric status:
_jb-get-script-path() {
#returns full path to current working directory
# + path to the script + name of the script file
echo "$PWD/${0#./*}"
}
_jb-get-script-dirname() {
local p="$(_jb-get-script-path)"
echo "${p##*/}"
}
_jb-get-script-dirname
I'm trying to store a value returned from a method like this: var=$(methodName), but the program never enters the method... It's weird because I do the same thing a few lines earlier (alreadyExists-variable in code sample), and it works fine. I had to do this: var='methodName' to make the program enter the method.
It works, so why care? I'm probably making a mistake, and I need to know what it is and learn from it. Let me know if you need more info to answer the question. Thanks!
overwriteOrNot()
{
echo DEBUG
# This debug string does not print if method is called from "local overwrite=$(overwriteOrNot)"
# but prints if method is called from "local overwrite='overwriteOrNot'"
...
}
local alreadyExists=$(studentNumberExists studentNumber)
if $alreadyExists ; then
# local overwrite=$(overwriteOrNot)
local overwrite='overwriteOrNot'
...
If you're using return, then you need to either directly branch on its result:
if overwriteOrNot; then
: "the function returned 0"
else
: "the function returned something other than 0"
fi
...or store the value of $? immediately after running the function:
overwriteOrNot
local overwrite=$?
Note that return can only return a single-byte integer. If you need to pass content which doesn't fit that type, it needs to be either passed on stdout or in a global variable.
The following:
local overwrite='overwriteOrNot'
assigns a string; it doesn't invoke a function. Instead:
local overwrite=$(overwriteOrNot)
You can check the return value from calling overwriteOrNot with the $? variable, or by checking its numeric return value directly in a conditional statement like:
if overwriteOrNot; then
:
fi
If you assign to overwrite, you can also check its value with any valid test condition such as equality, regular expression match, or emptiness. For example:
if [[ "$overwrite" == "foo" ]]; then
:
fi
Is there a way to print debug messages to the console from a PowerShell function that returns a value?
Example:
function A
{
$output = 0
# Start of awesome algorithm
WriteDebug # Magic function that prints debug messages to the console
#...
# End of awesome algorithm
return $output
}
# Script body
$result = A
Write-Output "Result=" $result
Is there a PowerShell function that fits this description?
I'm aware of Write-Output and Write-*, but in all my tests using any of those functions inside a function like the one above will not write any debug messages. I'm also aware that just calling the function without using the returned value will indeed cause the function to write debug messages.
Sure, use the Write-Debug cmdlet to do so. Note that by default you will not see debug output. In order to see the debug output, set $DebugPreference to Continue (instead of SilentlyContinue). For simple functions I will usually do something like this:
function A ([switch]$Debug) {
if ($Debug) { $DebugPreference = 'Continue' }
Write-Debug "Debug message about something"
# Generate output
"Output something from function"
}
Note that I would not recommend using the form return $output. Functions output anything that isn't captured by a variable, redirected to a file (or Out-Null) or cast to [void]. If you need to return early from a function then by all means use return.
For advanced functions you can get debug functionality a bit more easily because PowerShell provides the ubiquitous parameters for you, including -Debug:
function A {
[CmdletBinding()]
param()
End {
$pscmdlet.WriteDebug("Debug message")
"Output something from cmdlet"
}
}
FYI, it's the [CmdletBinding()] attribute on the param() statement is what makes this an advanced function.
Also don't forget about Write-Verbose and $pscmdlet.WriteVerbose() if you just want a way to output additional information that isn't debug related.