
    VAR1=value1 VAR2=value2 myScript args ...


Just put

    export HOME=/blah/whatever

at the point in the script where you want the change to happen. Since each process has its own set of environment variables, this definition will automatically cease to have any significance when the script terminates (and with it the instance of bash that has a changed environment).

Suppose I have the number `&#39;numb&#39;=1025 [00000000 00000000 00000100 00000001]` represented:

On Little-Endian Machine:

    00000001 00000100 00000000 00000000

On Big-Endian Machine:

    00000000 00000000 00000100 00000001

Now, if I apply Left Shift on 10 bits (i.e.: numb &lt;&lt;= 10), I should have:

[A] On Little-Endian Machine:

As I noticed in GDB, Little Endian does the Left Shift in 3 steps: [I have shown &#39;3&#39; Steps to better understand the processing only]

1. Treat the no. in Big-Endian Convention:

        00000000        00000000        00000100	00000001

2. Apply Left-Shift:

        00000000        00010000        00000100        00000000

3. Represent the Result again in Little-Endian:

        00000000        00000100        00010000        00000000 

[B]. On Big-Endian Machine:

    00000000        00010000        00000100        00000000


----------


My Question is:

If I directly apply a Left Shift on the Little Endian 
Convention, it should give:

`numb`:

    00000001 00000100 00000000 00000000

`numb &lt;&lt; 10`:

    00010000 00000000 00000000 00000000

But actually, it gives:

    00000000        00000100        00010000        00000000 

To achieve the second result only, I have shown three hypothetical steps above.

Please explain me why the above two results are different: The actual outcome of `numb &lt;&lt; 10` is different than the expected outcome.

Does bit-shift depend on endianness?

Why is this line needed in xml layout file?

    xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot; 

Why this line xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot; must be the first in the layout xml file?

On Linux ([Ubuntu 11.04][1] (Natty Narwhal)) in Bash, is it possible to temporarily set an environment variable that will only be different from the normal variable for the duration of the script?

For example, in a shell script, making an application that saves to HOME portable by temporarily setting HOME to a folder in the present working directory, and then launching the application.

  [1]: https://en.wikipedia.org/wiki/Ubuntu_version_history#Ubuntu_11.04_.28Natty_Narwhal.29






How can I set an environment variable only for the duration of the script?

<p>On Linux (<a href="https://en.wikipedia.org/wiki/Ubuntu_version_history#Ubuntu_11.04_.28Natty_Narwhal.29" target="_blank" rel="noopener noreferrer">Ubuntu 11.04</a> (Natty Narwhal)) in Bash, is it possible to temporarily set an environment variable that will only be different from the normal variable for the duration of the script?</p>
<p>For example, in a shell script, making an application that saves to HOME portable by temporarily setting HOME to a folder in the present working directory, and then launching the application.</p>


Is there any way to specify a field delimiter for more spaces with the cut command? (like &quot; &quot;+) ?
For example: In the following string, I like to reach value &#39;3744&#39;, what field delimiter I should say?

    $ps axu | grep jboss

    jboss     2574  0.0  0.0   3744  1092 ?        S    Aug17   0:00 /bin/sh /usr/java/jboss/bin/run.sh -c example.com -b 0.0.0.0

`cut -d&#39; &#39;` is not what I want, for it&#39;s only for one single space. 
`awk` is not what I am looking for either, but how to do with &#39;cut&#39;?

thanks. 


How to specify more spaces for the delimiter using cut?

How can I encrypt a large file  with a public key so that no one other than who has the private key be able to decrypt it?

I can make RSA public and private keys but when it comes to encrypting a large file using this command:

    openssl rsautl -encrypt -pubin -inkey public.pem -in myLargeFile.xml -out myLargeFile_encrypted.xml

and how can i perform the decryption also....

i create my private and public key by the following commands

    openssl genrsa -out private.pem 1024
    openssl rsa -in private.pem -out public.pem -outform PEM -pubout

I get this error:

    RSA operation error
    3020:error:0406D06E:rsa routines:RSA_padding_add_PKCS1_type_2:data too large for key size:.\crypto\rsa\rsa_pk1.c:151:

I tried to make keys with sizes from 1024 to 1200 bits, no luck, same error

How to encrypt a large file in openssl using public key

I&#39;ve successfully installed MongoDB on Windows (on a local machine) as a service, but now I want to move MongoDb to a separate server. So I extracted the tarball to a virtual server on network (running linux).

When I connected to the server (&quot;testmongoserver&quot;) using PuTTY from my local machine, I started the mongod server and it told me that it was listening to the default 28017 port. The mongo console is also working and allowed me to create a new database (testdb) and add users to it.

However, I could not access the server from remote. When I type `testmongoserver:28017` it doesn&#39;t open the HTTP console as `localhost:28017` on my local machine does. I also can&#39;t connect using official drivers and providing a connectionstring.

What are the neccesarry steps to install MongoDB on Linux, so that I could access it from a remote machine with a connectionstring and use its HTTP console via `testmongoserver:28017`

Thanks!

Getting MongoDB on Linux to listen to remote connections

Is that possible to use `grep` on a continuous stream?

What I mean is sort of a `tail -f &lt;file&gt;` command, but with `grep` on the output in order to keep only the lines that interest me.

I&#39;ve tried `tail -f &lt;file&gt; | grep pattern` but it seems that `grep` can only be executed once `tail` finishes, that is to say never.

How to &#39;grep&#39; a continuous stream?

Does Windows have Inode Numbers like Linux? How does Windows internally manage files?

Does Windows have Inode Numbers like Linux?

I suppose I could compare the number of files in the source directory to the number of files in the target directory as cp progresses, or perhaps do it with folder size instead? I tried to find examples, but all bash progress bars seem to be written for copying single files. I want to copy a bunch of files (or a directory, if the former is not possible).



How can I make a progress bar while copying a directory with cp?

I used to use CShell ([tag:csh]), which lets you make an alias that takes a parameter. The notation was something like
    
    alias junk=&quot;mv \\!* ~/.Trash&quot;

In Bash, this does not seem to work. Given that Bash has a multitude of useful features, I would assume that this one has been implemented but I am wondering how.


Make a Bash alias that takes a parameter?

I&#39;ve been meaning to find a solution for this for YEARS.

I am sooo much more productive in vim when manipulating files than bash for this reason.

If I have

    file_12390983421
    file_12391983421
    file_12340983421
    file_12390986421

In bash and type file_1-&gt;tab , it obviously lists: 

    file_12390983421 file_12391983421 file_12340983421 file_12390986421

And this is a horrible bore and painful to work with.

The same sequence in vim will loop through the files one at a time. 

Please someone tell me how to do this in bash, or if there is another shell that can do this, I&#39;ll switch tomorrow. 


How can I make bash tab completion behave like vim tab completion and cycle through matching matches?

I&#39;m pretty new at bash so this is a pretty noob question..

Suppose I have a string:

    string1 [string2] string3 string4

I would like to extract `string2` from the square brackets; but the brackets may be surrounding any other string at any other time. 

How would I use `sed`, etc, to do this? Thanks!

Extract string from brackets

I take part in developing a Java project, which uses some C++ components, thus I need `Jacob.dll`. (on Windows 7)

I keep getting `java.lang.UnsatisfiedLinkError: no JacobDB in java.library.path` no matter where I put Jacob.dll....

I looked for possible decisions and the one that I haven&#39;t tried so far is setting the `LD_LIBRARY_PATH` variable, pointing at the .dll file.

I have little experience and I&#39;m not familiar with what should be the meaning and usage of that variable - can you help me?

What is LD_LIBRARY_PATH and how to use it?

Which of the following is the best and most portable way to get the hostname of the current computer in Java?

`Runtime.getRuntime().exec(&quot;hostname&quot;)` 

vs 

`InetAddress.getLocalHost().getHostName()`

Recommended way to get hostname in Java

I am running windows xp 32bit

I just downloaded Openssl from the following URL and installed it.
[http://www.slproweb.com/products/Win32OpenSSL.html][1]


  [1]: http://www.slproweb.com/products/Win32OpenSSL.html

and then i tried to create a self signed certificate by using the following command

    openssl req -x509 -days 365 -newkey rsa:1024 -keyout hostkey.pem -nodes -out hostcert.pem

then it started giving the following error 

&gt; Unable to load config info from /usr/local/ssl/openssl.cnf

Then after googling sometime i changed the above command to 

    openssl req -config C:\OpenSSL\bin\openssl.conf -x509 -days 365 -newkey rsa:1024 -keyout hostkey.pem -nodes -out hostcert.pem

But now i get the following error in the command prompt

&gt; error on line -1 of C:\OpenSSL\bin\openssl.conf                       
&gt; 4220:error:02001002:system library:fopen:No such file or
&gt; directory:.\crypto\bio\bss_file.c:126:fopen(&#39;C:\OpenSSL\bin\openssl.conf&#39;,&#39;rb&#39;)
&gt; 4220:error:2006D080:BIO routines:BIO_new_file:no such
&gt; file:.\crypto\bio\bss_file.c:129:                                     
&gt; 4220:error:0E078072:configuration file routines:DEF_LOAD:no such
&gt; file:.\crypto\conf\conf_def.c:197:


Please help.
Thanks in advance.
                                                            

OpenSSL and error in reading openssl.conf file

Most of the applications we developers write need to be externally parametrized at startup. We pass file paths, pipe names, TCP/IP addresses etc. So far I&#39;ve been using **command line** to pass these to the appplication being launched. I had to parse the command line in `main` and direct the arguments to where they&#39;re needed, which is of course a _good design_, but is _hard to maintain_ for a large number of arguments. Recently I&#39;ve decided to use the **environment variables** mechanism. They are global and accessible from anywhere, which is _less elegant_ from architectural point of view, but _limits the amount of code_. 

These are my first (and possibly quite shallow) impressions on both strategies but I&#39;d like to hear opinions of more experienced developers -- **What are the ups and downs of using environment variables and command line arguments to pass arguments to a process?** I&#39;d like to take into account the following matters: 

 1. design quality (flexibility/maintainability), 
 2. memory constraints, 
 3. solution portability. 



----------

**Remarks:**

Ad. 1. This is the main aspect I&#39;m interested in. 

Ad. 2. This is a bit pragmatic. I know of some limitations on Windows which are currently [huge][1] (over 32kB for both command line and environment block). I guess this is not an issue though, since you just should use a file to pass tons of arguments if you need. 

Ad. 3. I know almost nothing of Unix so I&#39;m not sure whether both strategies are as similarily usable as on Windows. Elaborate on this if you please. 


  [1]: http://msdn.microsoft.com/en-us/library/ms682425.aspx

Argument passing strategy - environment variables vs. command line

When someone says &quot;edit your .plist file&quot; or &quot;your .profile&quot; or &quot;.bash_profile&quot; etc, this just confuses me. I have no idea where these files are, how to create them if I have to do that, etc, and also why there seem to be so many different ones (why? Do they do different things?)

So could someone please explain very patiently to a previous Windows user (wanting desperately to become more familiar with the pleasant if initially somewhat confusing OS X world) how to do this step by step?

I need the variables to be set both for GUI applications and command line applications, and at the moment it&#39;s for an ant script that needs the variables, but there will most likely be other needs as well.

Please note that I have Lion too, since many of the answers you get Googling seem to be outdated for Lion...

Also note that I have practically zero experience using the Terminal. I&#39;m willing to learn, but please explain for a novice...

Content Type	Original Author	Original Content on Stackoverflow
Question	suchipi	View Question on Stackoverflow
Solution 1 - Linux	Rockallite	View Answer on Stackoverflow
Solution 2 - Linux	glenn jackman	View Answer on Stackoverflow
Solution 3 - Linux	hmakholm left over Monica	View Answer on Stackoverflow

How can I set an environment variable only for the duration of the script?

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Why this line xmlns:android="http://schemas.android.com/apk/res/android" must be the first in the layout xml file?

Does bit-shift depend on endianness?

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