Keep pressing &lt;kbd&gt;Ctrl&lt;/kbd&gt;-&lt;kbd&gt;R&lt;/kbd&gt; and it will traverse your history.

If your search terms are a bit more complicated/ not contiguous, another option is to grep  among the `history` results, e.g.:

    history 300 | grep scp | grep important$

This will return a list of commands in your history that match, such as:

    3323  scp file1 user10@192.168.10.1:/home/user1/linuxfiles/samplecode/important
    3325  scp file1 user10@192.168.10.1:/home/user1/winfiles/samplecode/important

And you can then execute the relevant command with `!3325`.

I sometimes find this useful when running a lot of similar commands and may have to press &lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;R&lt;/kbd&gt; many times to get back to the exact command.

There is great alternative to &lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;R&lt;/kbd&gt; 

install https://github.com/dvorka/hstr

run it with &lt;code&gt;hh&lt;/code&gt; 

it shows a list of you all the last commands executed (contents of ./bash_history)  

if you start typing the list will be filtered based on what you type

you can use &lt;kbd&gt;Up&lt;/kbd&gt;/&lt;kbd&gt;Down&lt;/kbd&gt; arrows to select the desired command and select it with &lt;kbd&gt;Enter&lt;/kbd&gt;

I found this great tool **mcfly** as a replacement to the traditional Ctrl+R and it works really well. Basically you can see ALL the results as you type and you can select the command you are looking for. You can also customize the layout etc. I really recommend it.

https://github.com/cantino/mcfly

[![Example of mcfly session][1]][1]


  [1]: https://ostechnix.com/wp-content/uploads/2018/12/mcfly-demo.gif

I need to convert some xls files into xlsx files. I can successfully convert one xls file into xlsx by running this command into cmd prompt (windows):

    ssconvert inputFileName.xls outputFileName.xlsx

(ssconvert is a Gnumeric&#39;s command-line utility that can convert between different spreadsheet file formats)

I&#39;d like to write a batch file that FOR EACH file in a specified directory runs the command I wrote above, using the current file name both for input and for output filename.

For example, if I have this set of files:

    c:\directory\file1.xls
    c:\directory\file2.xls
    c:\directory\file3.xls


the output should be

    c:\directory\file1.xlsx
    c:\directory\file2.xlsx
    c:\directory\file3.xlsx

so the batch pseudo code should be something like

    directory = c:\directory\
    for (fileName in directory)
        ssconvert fileName.xls fileName.xlsx

Can anyone help me?

batch script - run command on each file in directory

I want to discover `bluetooth` devices in range, list and pair to them on click. I used following code but its just closing application when I click on device name which I want to pair.

I want to know mistake in my code or any other way to do what i need.

    

    package com.marakana;
    
        import java.util.Set;
    
        import android.app.Activity;
        import android.bluetooth.BluetoothAdapter;
        import android.bluetooth.BluetoothDevice;
        import android.content.BroadcastReceiver;
        import android.content.Context;
        import android.content.Intent;
        import android.content.IntentFilter;
        import android.os.Bundle;
        import android.util.Log;
        import android.view.View;
        import android.view.Window;
        import android.view.View.OnClickListener;
        import android.widget.AdapterView;
        import android.widget.ArrayAdapter;
        import android.widget.Button;
        import android.widget.ListView;
        import android.widget.TextView;
        import android.widget.AdapterView.OnItemClickListener;
    
     
        public class BluetoothDemo extends Activity {
        // Debugging
        private static final String TAG = &quot;DeviceListActivity&quot;;
        private static final boolean D = true;
    
        // Return Intent extra
        public static String EXTRA_DEVICE_ADDRESS = &quot;device_address&quot;;
    
        // Member fields
        private BluetoothAdapter mBtAdapter;
        private ArrayAdapter&lt;String&gt; mPairedDevicesArrayAdapter;
        private ArrayAdapter&lt;String&gt; mNewDevicesArrayAdapter;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    
            // Setup the window
            requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
            setContentView(R.layout.device_list);
    
            // Set result CANCELED incase the user backs out
            setResult(Activity.RESULT_CANCELED);
    
            // Initialize the button to perform device discovery
            Button scanButton = (Button) findViewById(R.id.button_scan);
            scanButton.setOnClickListener(new OnClickListener() {
                public void onClick(View v) {
                    doDiscovery();
                    v.setVisibility(View.GONE);
                }
            });
    
            // Initialize array adapters. One for already paired devices and
            // one for newly discovered devices
            mPairedDevicesArrayAdapter = new ArrayAdapter&lt;String&gt;(this, R.layout.device_name);
            mNewDevicesArrayAdapter = new ArrayAdapter&lt;String&gt;(this, R.layout.device_name);
    
            // Find and set up the ListView for paired devices
            ListView pairedListView = (ListView) findViewById(R.id.paired_devices);
            pairedListView.setAdapter(mPairedDevicesArrayAdapter);
            pairedListView.setOnItemClickListener(mDeviceClickListener);
    
            // Find and set up the ListView for newly discovered devices
            ListView newDevicesListView = (ListView) findViewById(R.id.new_devices);
            newDevicesListView.setAdapter(mNewDevicesArrayAdapter);
            newDevicesListView.setOnItemClickListener(mDeviceClickListener);
    
            // Register for broadcasts when a device is discovered
            IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
            this.registerReceiver(mReceiver, filter);
    
            // Register for broadcasts when discovery has finished
            filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
            this.registerReceiver(mReceiver, filter);
    
            // Get the local Bluetooth adapter
            mBtAdapter = BluetoothAdapter.getDefaultAdapter();
    
            // Get a set of currently paired devices
            Set&lt;BluetoothDevice&gt; pairedDevices = mBtAdapter.getBondedDevices();
    
            // If there are paired devices, add each one to the ArrayAdapter
            if (pairedDevices.size() &gt; 0) {
                findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
                for (BluetoothDevice device : pairedDevices) {
                    mPairedDevicesArrayAdapter.add(device.getName() + &quot;\n&quot; + device.getAddress());
                }
            } else {
                String noDevices = getResources().getText(R.string.none_paired).toString();
                mPairedDevicesArrayAdapter.add(noDevices);
            }
        }
    
        @Override
        protected void onDestroy() {
            super.onDestroy();
    
            // Make sure we&#39;re not doing discovery anymore
            if (mBtAdapter != null) {
                mBtAdapter.cancelDiscovery();
            }
    
            // Unregister broadcast listeners
            this.unregisterReceiver(mReceiver);
        }
    
        /**
         * Start device discover with the BluetoothAdapter
         */
        private void doDiscovery() {
            if (D) Log.d(TAG, &quot;doDiscovery()&quot;);
    
            // Indicate scanning in the title
            setProgressBarIndeterminateVisibility(true);
            setTitle(R.string.scanning);
    
            // Turn on sub-title for new devices
            findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);
    
            // If we&#39;re already discovering, stop it
            if (mBtAdapter.isDiscovering()) {
                mBtAdapter.cancelDiscovery();
            }
    
            // Request discover from BluetoothAdapter
            mBtAdapter.startDiscovery();
        }
    
        // The on-click listener for all devices in the ListViews
        private OnItemClickListener mDeviceClickListener = new OnItemClickListener() {
            public void onItemClick(AdapterView&lt;?&gt; av, View v, int arg2, long arg3) {
                // Cancel discovery because it&#39;s costly and we&#39;re about to connect
                mBtAdapter.cancelDiscovery();
    
                // Get the device MAC address, which is the last 17 chars in the View
                String info = ((TextView) v).getText().toString();
                String address = info.substring(info.length() - 17);
    
                // Create the result Intent and include the MAC address
                Intent intent = new Intent();
                intent.putExtra(EXTRA_DEVICE_ADDRESS, address);
    
                // Set result and finish this Activity
                setResult(Activity.RESULT_OK, intent);
                finish();
            }
        };
    
        // The BroadcastReceiver that listens for discovered devices and
        // changes the title when discovery is finished
        private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                String action = intent.getAction();
    
                // When discovery finds a device
                if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                    // Get the BluetoothDevice object from the Intent
                    BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                    // If it&#39;s already paired, skip it, because it&#39;s been listed already
                    if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
                        mNewDevicesArrayAdapter.add(device.getName() + &quot;\n&quot; + device.getAddress());
                    }
                // When discovery is finished, change the Activity title
                } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED.equals(action)) {
                    setProgressBarIndeterminateVisibility(false);
                    setTitle(R.string.select_device);
                    if (mNewDevicesArrayAdapter.getCount() == 0) {
                        String noDevices = getResources().getText(R.string.none_found).toString();
                        mNewDevicesArrayAdapter.add(noDevices);
                    }
                }
            }
        };
    }

   

             

Android + Pair devices via bluetooth programmatically

I think an example will be good to understand my question.

    ...
    scp file1 user10@192.168.10.1:/home/user1/linuxfiles/samplecode/important
    ...
    ...
    scp file1 user10@192.168.10.1:/home/user1/linuxfiles/samplecode/important/tested
    ...
    ...

Assume that is the order of commands in history. If I am doing &lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;R&lt;/kbd&gt; and type `scp` it will show the last executed `scp` command ( ie the line ending with &#39;tested&#39;) . 

But I want to locate the scp command ending with &#39;important&#39;. So is there any way in this `reverse-i-search` to view all commands starting with scp, to choose the appropriate one?

In reverse-i-search (Ctrl+R ) ,Any method to switch between similar commands in history

I think an example will be good to understand my question.
<pre><code class="hljs language-ruby">...
scp file1 user10@192.168.10.1:/home/user1/linuxfiles/samplecode/important
...
...
scp file1 user10@192.168.10.1:/home/user1/linuxfiles/samplecode/important/tested
...
...
</code></pre>
Assume that is the order of commands in history. If I am doing <kbd>Ctrl</kbd>+<kbd>R</kbd> and type <code>scp</code> it will show the last executed <code>scp</code> command ( ie the line ending with 'tested') .
But I want to locate the scp command ending with 'important'. So is there any way in this <code>reverse-i-search</code> to view all commands starting with scp, to choose the appropriate one?

I&#39;m trying to create a log file at the start of my program.

I need to check if a `/log` directory exists if it doesn&#39;t create the directory then move on to creating the log file.

Well I tried to use `os.Mkdir` (as well as `os.MkdirAll`), but no matter what value I put into the second parameter I get a locked out folder with no permissions. What value should this be in order to get a read / write for user folder? I thought it would be `0x700` but it doesn&#39;t seem to work.

Thanks!

os.Mkdir and os.MkdirAll permissions

I am seeking to run a common Java program in both Windows and Linux.

The program needs to do some things differently on each platform.

So how can / should my Java program detect it is running under Linux vs. Windows?

Detecting Windows or Linux?

I have a tar.gz-file with the following structure:

    folder1/img.gif
    folder2/img2.gif
    folder3/img3.gif

I want to extract the image files without the folder hierarchy so the extracted result looks like:

    /img.gif
    /img2.gif
    /img3.gif

I need to do this with a combination of Unix and PHP. Here is what I have so far, it works to extract them to the specified directory but keeps the folder hierarchy:

    exec(&#39;gtar --keep-newer-files -xzf images.tgz -C /home/user/public_html/images/&#39;,$ret);


How do I extract files without folder structure using tar

I recently had to upgrade to a VPS server (HostGator Linux) because I wanted to run a script that was a bit more complicated than the regular PHP db manipulation. I&#39;m trying to install a JDK and Apache Ant (if it matters, for compiling Android Apps on server).

I watched tutorials on Linux Bash and started using it. I am currently trying to install Java (with JDK and JRE) on to the server.

I am following the tutorial on this page:
http://www.oracle.com/technetwork/java/javase/install-linux-64-self-extracting-142068.html

However, I don&#39;t know what to do at this line:

 1. Download and check the download file size.

    You can download to any directory that you can write to.

How do I download Java from the command line?

If it matters, I am running CentOS v5.8

How do I download a file from the internet to my linux server with Bash

From wiki [Executable and Linkable Format](https://en.wikipedia.org/wiki/Executable_and_Linkable_Format):

&gt; The segments contain information that is necessary for runtime execution of the file, while sections contain important data for linking and relocation. Any byte in the entire file can be owned by at most one section, and there can be orphan bytes which are not owned by any section.

But what is the difference between section and segment? 
In an executable ELF file, does a segment contain one or more sections?

What&#39;s the difference of section and segment in ELF file format

How do I make sure that all my background processes have finished execution before I exit my script (TCL/Bash).

I was thinking of writing all my background process pids to a pidfile. And then at the end pgrep the pidfile to see if any processes are still running before I exit. 

Is there some simpler way to do this? And is there a TCL specific way to do this?

Waiting for background processes to finish before exiting script

Using iTerm2 with zsh and it isn&#39;t recognizing my aliases. Sometimes I have to work in an IDE and can&#39;t just easily vim something and the stupid people thought it a good idea to name their applications like MyReallyLongApplicationName.app and since .html files open by default in browsers, I have to:

    open -a MyReallyLongApplicationName.app something.html

I have an alias in my .zshrc like:

    alias ide=&quot;open -a MyReallyLongApplicationName.app&quot;

But zsh won&#39;t recognize my aliases. I tried another one just to see if it was me but none of the aliases I create are recognized. Just get &quot;zsh: command not found: ide&quot; or whatever.

So I&#39;m not sure what I&#39;m doing wrong and I&#39;ve been searching around all day trying to fix things in zsh and the like. As a note, I&#39;m not a pro at Linux/Unix systems so if you&#39;re too technical and vague I probably won&#39;t understand what you&#39;re telling me.

Thanks!

ZSH not recognizing my aliases?

I am trying to add a variable to the middle of a variable, so for instance in PHP I would do this:

    $mystring = $arg1 . &#39;12&#39; . $arg2 . &#39;endoffile&#39;;

so the output might be ``20121201endoffile``, how can I achieve the same in a linux bash script?

Concatenating variables in Bash

Straight to the point, I&#39;m wondering how to use grep/find/sed/awk to match a certain string (that ends with a number) and increment that number by 1. The closest I&#39;ve come is to concatenate a 1 to the end (which works well enough) because the main point is to simply change the value. Here&#39;s what I&#39;m currently doing:

    find . -type f | xargs sed -i &#39;s/$\?cache_version\=[0-9]\+$/\11/g&#39;

Since I couldn&#39;t figure out how to increment the number, I captured the whole thing and just appended a &quot;1&quot;. Before, I had something like this:

    find . -type f | xargs sed -i &#39;s/\?cache_version\=$[0-9]\+$/?cache_version=\11/g&#39;

So at least I understand how to capture what I need.

Instead of explaining what this is for, I&#39;ll just explain what I want it to do. It should find text in any file, recursively, based on the current directory (isn&#39;t important, it could be any directory, so I&#39;d configure that later), that matches &quot;?cache_version=&quot; with a number. It will then increment that number and replace it in the file.

Currently the stuff I have above works, it&#39;s just that I can&#39;t increment that found number at the end. It would be nicer to be able to increment instead of appending a &quot;1&quot; so that the future values wouldn&#39;t be &quot;11&quot;, &quot;111&quot;, &quot;1111&quot;, &quot;11111&quot;, and so on.

I&#39;ve gone through dozens of articles/explanations, and often enough, the suggestion is to use `awk`, but I cannot for the life of me mix them. The closest I came to using `awk`, which doesn&#39;t actually replace anything, is:

    grep -Pro &#39;(?&lt;=\?cache_version=)[0-9]+&#39; . | awk -F: &#39;{ print &quot;match is&quot;, $2+1 }&#39;

I&#39;m wondering if there&#39;s some way to pipe a `sed` at the end and pass the original file name so that `sed` can have the file name and incremented number (from the `awk`), or whatever it needs that `xargs` has.

Technically, this number has no importance; this replacement is mainly to make sure there is a new number there, 100% for sure different than the last. So as I was writing this question, I realized I might as well use the system time - seconds since epoch (the technique often used by AJAX to eliminate caching for subsequent &quot;identical&quot; requests). I ended up with this, and it seems perfect:

    CXREPLACETIME=`date +%s`; find . -type f | xargs sed -i &quot;s/$\?cache_version\=$[0-9]\+/\1$CXREPLACETIME/g&quot;

(I store the value first so all files get the same value, in case it spans multiple seconds for whatever reason)

But I would still love to know the original question, on incrementing a matched number. I&#39;m guessing an easy solution would be to make it a bash script, but still, I thought there would be an easier way than looping through every file recursively and checking its contents for a match then replacing, since it&#39;s simply incrementing a matched number...not much else logic. I just don&#39;t want to write to any other files or something like that - it should do it in place, like `sed` does with the &quot;i&quot; option.

How to find/replace and increment a matched number with sed/awk?

This command lists directories in the current path: `ls -d */`

What exactly does the pattern `*/` do?

And how can we give the absolute path in the above command (e.g. `ls -d /home/alice/Documents`) for listing only directories in that path?

Listing only directories using ls in Bash?

Suppose I need to build a whole solution (which has multiple projects) in command line, is it possible to run a clean build for a particular projects and run an incremental build for the rest of the project?

Thanks.

How to run a clean build for a particular project from a solution in visual studio

I have a fixed-width-field file which I&#39;m trying to sort using the UNIX (Cygwin, in my case) sort utility.

The problem is there is a two-line header at the top of the file which is being sorted to the bottom of the file (as each header line begins with a colon).

Is there a way to tell sort either &quot;pass the first two lines across unsorted&quot; or to specify an ordering which sorts the colon lines to the top - the remaining lines are always start with a 6-digit numeric (which is actually the key I&#39;m sorting on) if that helps.

Example:

    :0:12345
    :1:6:2:3:8:4:2
    010005TSTDOG_FOOD01
    500123TSTMY_RADAR00
    222334NOTALINEOUT01
    477821USASHUTTLES21
    325611LVEANOTHERS00

should sort to:

    :0:12345
    :1:6:2:3:8:4:2
    010005TSTDOG_FOOD01
    222334NOTALINEOUT01
    325611LVEANOTHERS00
    477821USASHUTTLES21
    500123TSTMY_RADAR00


Is there a way to ignore header lines in a UNIX sort?

How can I use the curl command line program to send an email from a gmail account?

I have tried the following:

    curl -n --ssl-reqd --mail-from &quot;&lt;sender@gmail.com&gt;&quot; --mail-rcpt &quot;&lt;receiver@server.tld&gt;&quot; --url smtps://smtp.gmail.com:465 -T file.txt

With file.txt being the email&#39;s contents, however, when I run this command I get the following error:

    curl: (67) Access denied: 530

Is it possible to send an email from an account that is hosted by a personal server, still using curl? Does that make the authentication process easier?

Using curl to send email

If from inside a bat file you called another batch file but still had a few remaining operations to complete, how can you make sure that the call to first bat file will after completion or error, will return to the file that called it in the first instance?

Example:

    CD:\MyFolder\MyFiles
    Mybatfile.bat
    
    Copy afile toHere

or

    CD:\MyFolder\MyFiles
    CALL Mybatfile.bat
    
    COPY afile toHere

What is the difference between using `CALL` or `START` or none of them at all? Would this have any impact on whether it would return for the results of the copy command or not?

To &quot;Call&quot; or &quot;Not to Call&quot; a batch file?

I&#39;m using the `subprocess.Popen` call, and in another question I found out that I had been misunderstanding how Python was generating arguments for the command line.  

**My Question**  
Is there a way to find out what the actual command line was?  

Example Code :-

    proc = subprocess.popen(....)
    print &quot;the commandline is %s&quot; % proc.getCommandLine()

How would you write `getCommandLine` ?

Content Type	Original Author	Original Content on Stackoverflow
Question	Arun	View Question on Stackoverflow
Solution 1 - Linux	jgr	View Answer on Stackoverflow
Solution 2 - Linux	Bonlenfum	View Answer on Stackoverflow
Solution 3 - Linux	GiorgosK	View Answer on Stackoverflow
Solution 4 - Linux	rkachach	View Answer on Stackoverflow

In reverse-i-search (Ctrl+R ) ,Any method to switch between similar commands in history

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Android + Pair devices via bluetooth programmatically

batch script - run command on each file in directory

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