Some Of The Best Answers From Latest Asked Questions
BAT file: Open new cmd window and execute a command in there
You may already find your answer because it was some time ago you asked. But I tried to do something similar when coding ror. I wanted to run "rails server" in a new cmd window so I don't have to open a new cmd and then find my path again.
What I found out was to use the K switch like this:
start cmd /k echo Hello, World!
start before "cmd" will open the application in a new window and "/K" will execute "echo Hello, World!" after the new cmd is up.
You can also use the /C switch for something similar.
start cmd /C pause
This will then execute "pause" but close the window when the command is done. In this case after you pressed a button. I found this useful for "rails server", then when I shutdown my dev server I don't have to close the window after.
Use the following in your batch file:
start cmd.exe /c "more-batch-commands-here"
or
start cmd.exe /k "more-batch-commands-here"
/c Carries out the command
specified by string and then
terminates
/k Carries out the
command specified by string but
remains
The /c
and /k
options controls what happens once your command finishes running. With /c
the terminal window will close automatically, leaving your desktop clean. With /k
the terminal window will remain open. It's a good option if you want to run more commands manually afterwards.
Consult the cmd.exe documentation using cmd /?
for more details.
Escaping Commands with White Spaces
The proper formatting of the command string becomes more complicated when using arguments with spaces. See the examples below. Note the nested double quotes in some examples.
Examples:
Run a program and pass a filename parameter:
CMD /c write.exe c:\docs\sample.txt
Run a program and pass a filename which contains whitespace:
CMD /c write.exe "c:\sample documents\sample.txt"
Spaces in program path:
CMD /c ""c:\Program Files\Microsoft Office\Office\Winword.exe""
Spaces in program path + parameters:
CMD /c ""c:\Program Files\demo.cmd"" Parameter1 Param2
CMD /k ""c:\batch files\demo.cmd" "Parameter 1 with space" "Parameter2 with space""
Launch demo1 and demo2:
CMD /c ""c:\Program Files\demo1.cmd" & "c:\Program Files\demo2.cmd""
Source: http://ss64.com/nt/cmd.html
How to provide a file download from a JSF backing bean?
Introduction
You can get everything through ExternalContext
. In JSF 1.x, you can get the raw HttpServletResponse
object by ExternalContext#getResponse()
. In JSF 2.x, you can use the bunch of new delegate methods like ExternalContext#getResponseOutputStream()
without the need to grab the HttpServletResponse
from under the JSF hoods.
On the response, you should set the Content-Type
header so that the client knows which application to associate with the provided file. And, you should set the Content-Length
header so that the client can calculate the download progress, otherwise it will be unknown. And, you should set the Content-Disposition
header to attachment
if you want a Save As dialog, otherwise the client will attempt to display it inline. Finally just write the file content to the response output stream.
Most important part is to call FacesContext#responseComplete()
to inform JSF that it should not perform navigation and rendering after you've written the file to the response, otherwise the end of the response will be polluted with the HTML content of the page, or in older JSF versions, you will get an IllegalStateException
with a message like getoutputstream() has already been called for this response
when the JSF implementation calls getWriter()
to render HTML.
Turn off ajax / don't use remote command!
You only need to make sure that the action method is not called by an ajax request, but that it is called by a normal request as you fire with <h:commandLink>
and <h:commandButton>
. Ajax requests and remote commands are handled by JavaScript which in turn has, due to security reasons, no facilities to force a Save As dialogue with the content of the ajax response.
In case you're using e.g. PrimeFaces <p:commandXxx>
, then you need to make sure that you explicitly turn off ajax via ajax="false"
attribute. In case you're using ICEfaces, then you need to nest a <f:ajax disabled="true" />
in the command component.
Generic JSF 2.x example
public void download() throws IOException {
FacesContext fc = FacesContext.getCurrentInstance();
ExternalContext ec = fc.getExternalContext();
ec.responseReset();
ec.setResponseContentType(contentType);
ec.setResponseContentLength(contentLength);
ec.setResponseHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
OutputStream output = ec.getResponseOutputStream();
fc.responseComplete();
}
Generic JSF 1.x example
public void download() throws IOException {
FacesContext fc = FacesContext.getCurrentInstance();
HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();
response.reset();
response.setContentType(contentType);
response.setContentLength(contentLength);
response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
OutputStream output = response.getOutputStream();
fc.responseComplete();
}
Common static file example
In case you need to stream a static file from the local disk file system, substitute the code as below:
File file = new File("/path/to/file.ext");
String fileName = file.getName();
String contentType = ec.getMimeType(fileName); // JSF 1.x: ((ServletContext) ec.getContext()).getMimeType(fileName);
int contentLength = (int) file.length();
// ...
Files.copy(file.toPath(), output);
Common dynamic file example
In case you need to stream a dynamically generated file, such as PDF or XLS, then simply provide output
there where the API being used expects an OutputStream
.
E.g. iText PDF:
String fileName = "dynamic.pdf";
String contentType = "application/pdf";
Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, output);
document.open();
document.close();
E.g. Apache POI HSSF:
String fileName = "dynamic.xls";
String contentType = "application/vnd.ms-excel";
HSSFWorkbook workbook = new HSSFWorkbook();
workbook.write(output);
workbook.close();
Note that you cannot set the content length here. So you need to remove the line to set response content length. This is technically no problem, the only disadvantage is that the enduser will be presented an unknown download progress. In case this is important, then you really need to write to a local (temporary) file first and then provide it as shown in previous chapter.
Utility method
If you're using JSF utility library OmniFaces, then you can use one of the three convenient Faces#sendFile()
methods taking either a File
, or an InputStream
, or a byte[]
, and specifying whether the file should be downloaded as an attachment (true
) or inline (false
).
public void download() throws IOException {
Faces.sendFile(file, true);
}
Yes, this code is complete as-is. You don't need to invoke responseComplete()
and so on yourself. This method also properly deals with IE-specific headers and UTF-8 filenames. You can find source code here.
How do I position a div at the bottom center of the screen
If you aren't comfortable with using negative margins, check this out.
div {
position: fixed;
left: 50%;
bottom: 20px;
transform: translate(-50%, -50%);
margin: 0 auto;
}
<div>
Your Text
</div>
Especially useful when you don't know the width of the div.
align="center"
has no effect.
Since you have position:absolute
, I would recommend positioning it 50% from the left and then subtracting half of its width from its left margin.
#manipulate {
position:absolute;
width:300px;
height:300px;
background:#063;
bottom:0px;
right:25%;
left:50%;
margin-left:-150px;
}
How to create a file in Linux from terminal window?
Depending on what you want the file to contain:
touch /path/to/file
for an empty file
somecommand > /path/to/file
for a file containing the output of some command.
eg: grep --help > randomtext.txt
echo "This is some text" > randomtext.txt
nano /path/to/file
or vi /path/to/file
(or any other editor emacs,gedit etc
)
It either opens the existing one for editing or creates & opens the empty file to enter, if it doesn't exist
Create the file using cat
$ cat > myfile.txt
Now, just type whatever you want in the file:
Hello World!
CTRL-D to save and exit
There are several possible solutions:
Create an empty file
touch file
>file
echo -n > file
printf '' > file
The echo
version will work only if your version of echo
supports the -n
switch to suppress newlines. This is a non-standard addition. The other examples will all work in a POSIX shell.
Create a file containing a newline and nothing else
echo '' > file
printf '\n' > file
This is a valid "text file" because it ends in a newline.
Write text into a file
"$EDITOR" file
echo 'text' > file
cat > file <<END \
text
END
printf 'text\n' > file
These are equivalent. The $EDITOR
command assumes that you have an interactive text editor defined in the EDITOR environment variable and that you interactively enter equivalent text. The cat
version presumes a literal newline after the \
and after each other line. Other than that these will all work in a POSIX shell.
Of course there are many other methods of writing and creating files, too.
Excel VBA - Delete empty rows
How about
sub foo()
dim r As Range, rows As Long, i As Long
Set r = ActiveSheet.Range("A1:Z50")
rows = r.rows.Count
For i = rows To 1 Step (-1)
If WorksheetFunction.CountA(r.rows(i)) = 0 Then r.rows(i).Delete
Next
End Sub
Try this
Option Explicit
Sub Sample()
Dim i As Long
Dim DelRange As Range
On Error GoTo Whoa
Application.ScreenUpdating = False
For i = 1 To 50
If Application.WorksheetFunction.CountA(Range("A" & i & ":" & "Z" & i)) = 0 Then
If DelRange Is Nothing Then
Set DelRange = Range("A" & i & ":" & "Z" & i)
Else
Set DelRange = Union(DelRange, Range("A" & i & ":" & "Z" & i))
End If
End If
Next i
If Not DelRange Is Nothing Then DelRange.Delete shift:=xlUp
LetsContinue:
Application.ScreenUpdating = True
Exit Sub
Whoa:
MsgBox Err.Description
Resume LetsContinue
End Sub
IF you want to delete the entire row then use this code
Option Explicit
Sub Sample()
Dim i As Long
Dim DelRange As Range
On Error GoTo Whoa
Application.ScreenUpdating = False
For i = 1 To 50
If Application.WorksheetFunction.CountA(Range("A" & i & ":" & "Z" & i)) = 0 Then
If DelRange Is Nothing Then
Set DelRange = Rows(i)
Else
Set DelRange = Union(DelRange, Rows(i))
End If
End If
Next i
If Not DelRange Is Nothing Then DelRange.Delete shift:=xlUp
LetsContinue:
Application.ScreenUpdating = True
Exit Sub
Whoa:
MsgBox Err.Description
Resume LetsContinue
End Sub
get current url in twig template?
{{ path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) }}
If you want to read it into a view variable:
{% set currentPath = path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) %}
The app
global view variable contains all sorts of useful shortcuts, such as app.session
and app.security.token.user
, that reference the services you might use in a controller.
More elegant "ps aux | grep -v grep"
You could use preg_split
instead of explode
and split on [ ]+
(one or more spaces). But I think in this case you could go with preg_match_all
and capturing:
preg_match_all('/[ ]php[ ]+\S+[ ]+(\S+)/', $input, $matches);
$result = $matches[1];
The pattern matches a space, php
, more spaces, a string of non-spaces (the path), more spaces, and then captures the next string of non-spaces. The first space is mostly to ensure that you don't match php
as part of a user name but really only as a command.
An alternative to capturing is the "keep" feature of PCRE. If you use \K
in the pattern, everything before it is discarded in the match:
preg_match_all('/[ ]php[ ]+\S+[ ]+\K\S+/', $input, $matches);
$result = $matches[0];
I would use preg_match()
. I do something similar for many of my system management scripts. Here is an example:
$test = "user 12052 0.2 0.1 137184 13056 ? Ss 10:00 0:00 php /home/user/public_html/utilities/runProcFile.php cust1 cron
user 12054 0.2 0.1 137184 13064 ? Ss 10:00 0:00 php /home/user/public_html/utilities/runProcFile.php cust3 cron
user 12055 0.6 0.1 137844 14220 ? Ss 10:00 0:00 php /home/user/public_html/utilities/runProcFile.php cust4 cron
user 12057 0.2 0.1 137184 13052 ? Ss 10:00 0:00 php /home/user/public_html/utilities/runProcFile.php cust89 cron
user 12058 0.2 0.1 137184 13052 ? Ss 10:00 0:00 php /home/user/public_html/utilities/runProcFile.php cust435 cron
user 12059 0.3 0.1 135112 13000 ? Ss 10:00 0:00 php /home/user/public_html/utilities/runProcFile.php cust16 cron
root 12068 0.0 0.0 106088 1164 pts/1 S+ 10:00 0:00 sh -c ps aux | grep utilities > /home/user/public_html/logs/dashboard/currentlyPosting.txt
root 12070 0.0 0.0 103240 828 pts/1 R+ 10:00 0:00 grep utilities";
$lines = explode("\n", $test);
foreach($lines as $line){
if(preg_match("/.php[\s+](cust[\d]+)[\s+]cron/i", $line, $matches)){
print_r($matches);
}
}
The above prints:
Array
(
[0] => .php cust1 cron
[1] => cust1
)
Array
(
[0] => .php cust3 cron
[1] => cust3
)
Array
(
[0] => .php cust4 cron
[1] => cust4
)
Array
(
[0] => .php cust89 cron
[1] => cust89
)
Array
(
[0] => .php cust435 cron
[1] => cust435
)
Array
(
[0] => .php cust16 cron
[1] => cust16
)
You can set $test
to equal the output from exec. the values you are looking for would be in the if
statement under the foreach
. $matches[1]
will have the custx value.
Default text which won't be shown in drop-down list
Kyle's solution worked perfectly fine for me so I made my research in order to avoid any Js and CSS, but just sticking with HTML.
Adding a value of selected
to the item we want to appear as a header forces it to show in the first place as a placeholder.
Something like:
<option selected disabled>Choose here</option>
The complete markup should be along these lines:
<select>
<option selected disabled>Choose here</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
<option value="4">Four</option>
<option value="5">Five</option>
</select>
You can take a look at this fiddle, and here's the result:
If you do not want the sort of placeholder text to appear listed in the options once a user clicks on the select box just add the hidden
attribute like so:
<select>
<option selected disabled hidden>Choose here</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
<option value="4">Four</option>
<option value="5">Five</option>
</select>
Check the fiddle here and the screenshot below.
Here is the solution:
<select>
<option style="display:none;" selected>Select language</option>
<option>Option 1</option>
<option>Option 2</option>
</select>
performing HTTP requests with cURL (using PROXY)
From man curl
:
-x, --proxy <[protocol://][user:password@]proxyhost[:port]>
Use the specified HTTP proxy.
If the port number is not specified, it is assumed at port 1080.
General way:
export http_proxy=http://your.proxy.server:port/
Then you can connect through proxy from (many) application.
And, as per comment below, for https:
export https_proxy=https://your.proxy.server:port/
How to show all rows by default in JQuery DataTable
Use:
$('#example').dataTable({
aLengthMenu: [
[25, 50, 100, 200, -1],
[25, 50, 100, 200, "All"]
],
iDisplayLength: -1
});
Or if using 1.10+
$('#example').dataTable({
paging: false
});
The option you should use is iDisplayLength:
$('#adminProducts').dataTable({
'iDisplayLength': 100
});
$('#table').DataTable({
"lengthMenu": [ [5, 10, 25, 50, -1], [5, 10, 25, 50, "All"] ]
});
It will Load by default all entries.
$('#example').dataTable({
aLengthMenu: [
[25, 50, 100, 200, -1],
[25, 50, 100, 200, "All"]
],
iDisplayLength: -1
});
Or if using 1.10+
$('#example').dataTable({
paging: false
});
If you want to load by default 25 not all do this.
$('#example').dataTable({
aLengthMenu: [
[25, 50, 100, 200, -1],
[25, 50, 100, 200, "All"]
],
});
How can I use if/else in a dictionary comprehension?
You've already got it: A if test else B
is a valid Python expression. The only problem with your dict comprehension as shown is that the place for an expression in a dict comprehension must have two expressions, separated by a colon:
{ (some_key if condition else default_key):(something_if_true if condition
else something_if_false) for key, value in dict_.items() }
The final if
clause acts as a filter, which is different from having the conditional expression.
Worth mentioning that you don't need to have an if-else condition for both the key and the value. For example, {(a if condition else b): value for key, value in dict.items()} will work.