    file_name=test.log

    # set first K lines:
    K=1000

    # line count (N): 
    N=$(wc -l &lt; $file_name)

    # length of the bottom file:
    L=$(( $N - $K ))

    # create the top of file: 
    head -n $K $file_name &gt; top_$file_name

    # create bottom of file: 
    tail -n $L $file_name &gt; bottom_$file_name


Also, on second thought, split will work in your case, since the first split is larger than the second.  Split puts the balance of the input into the last split, so

`split -l 300000 file_name`

will output `xaa` with 300k lines and `xab` with 100k lines, for an input with 400k lines.

In which situations you should use inherited tables? I tried to use them very briefly and inheritance didn&#39;t seem like in OOP world.

I thought it worked like this:

Table `users` has all fields required for all user levels. Tables like `moderators`, `admins`, `bloggers`, etc but fields are **not** checked from parent. For example `users` has email field and inherited `bloggers` has it now too but it&#39;s not unique for both `users` and `bloggers` at the same time. ie. same as I add email field to both tables.

The only usage I could think of is fields that are usually used, like **row_is_deleted**, **created_at**, **modified_at**. Is this the only usage for inherited tables?



When to use inherited tables in PostgreSQL?

This is more of a documentation than a real question. This does not seem to have been addressed on SO yet (unless I missed it), so here goes:

Imagine a generic class that contains a static member:

    class Foo&lt;T&gt; {
        public static int member;
    }

Is there a new instance of the member for each specific class, or is there only a single instance for all Foo-type classes?

It can easily be verified by code like this:

    Foo&lt;int&gt;.member = 1;
    Foo&lt;string&gt;.member = 2;
    Console.WriteLine (Foo&lt;int&gt;.member);

What is the result, and where is this behavior documented?

Are static members of a generic class tied to the specific instance?

I want to split a 400k line long log file from a particular line number.

For this question, lets make this an arbitrary number 300k.

Is there a linux command that allows me to do this (**within the script**)?

I know `split` lets me split the file in equal parts either by size or line numbers but that&#39;s not what I want. I want to the first 300k in one file and the last 100k in the second file.

Any help would be appreciated. Thanks!

**On second thoughts this would be more suited to the superuser or serverfault site.**

How to file split at a line number

I want to split a 400k line long log file from a particular line number.
For this question, lets make this an arbitrary number 300k.
Is there a linux command that allows me to do this (within the script)?
I know <code>split</code> lets me split the file in equal parts either by size or line numbers but that's not what I want. I want to the first 300k in one file and the last 100k in the second file.
Any help would be appreciated. Thanks!
On second thoughts this would be more suited to the superuser or serverfault site.

I need to get the final URL after a page redirect preferably with curl or wget.

For example *http://google.com* may redirect to *http://www.google.com*.

The contents are easy to get(ex. `curl --max-redirs 10 http://google.com -L`), but I&#39;m only interested in the final url (in the former case http://www.google.com).

Is there any way of doing this by using only Linux built-in tools? (command line only)

Get final URL after curl is redirected

How to print just the last line of a file?

Print the last line of a file, from the CLI

I&#39;m just learning tmux and I have no experience with screen. I&#39;m wondering if I can move a window in one tmux client to another tmux client. I want to move my IRC client to a new window on my screen.

Move window between tmux clients

I am writing a Linux daemon . I found two ways to do it.

1. Daemonize your process by calling `fork()` and setting `sid`.
2. Running your program with `&amp;`.

Which is the right way to do it?

Linux daemonize

How do I implement fork and exec in bash?

Let us suppose script as

    echo &quot;Script starts&quot;
    
    function_to_fork(){
    sleep 5
    echo &quot;Hello&quot;
    }
    
    echo &quot;Script ends&quot;


Basically I want that function to be called as new process like in C we use fork and exec calls..

From the script it is expected that the parent script will end and then after 5 seconds, &quot;Hello&quot; is printed.


fork and exec in bash

In a bash script, I need to launch the user web browser. There seems to be many ways of doing this:

* `$BROWSER`
* `xdg-open`
* `gnome-open` on GNOME
* `www-browser`
* `x-www-browser`
* ...

Is there a more-standard-than-the-others way to do this that would work on most platforms, or should I just go with something like this:

    #/usr/bin/env bash
    
    if [ -n $BROWSER ]; then
      $BROWSER &#39;http://wwww.google.com&#39;
    elif which xdg-open &gt; /dev/null; then
      xdg-open &#39;http://wwww.google.com&#39;
    elif which gnome-open &gt; /dev/null; then
      gnome-open &#39;http://wwww.google.com&#39;
    # elif bla bla bla...
    else
      echo &quot;Could not detect the web browser to use.&quot;
    fi



Clean way to launch the web browser from shell script?

I have the following data, and I need to put it all into one line.

I have this:

    22791
    
    ;
    
    14336
    
    ;
    
    22821
    
    ;
    
    34653
    
    ;
    
    21491
    
    ;
    
    25522
    
    ;
    
    33238
    
    ;

I need this:

    22791;14336;22821;34653;21491;25522;33238;


---------
# EDIT

None of these commands is working perfectly.

Most of them let the data look like this:

    22791
    
    ;14336
    
    ;22821
    
    ;34653
    
    ;21491
    
    ;25522


How do I remove newlines from a text file?

I know how to **redirect stdout** to a file:

    exec &gt; foo.log
    echo test

this will put the &#39;test&#39; into the foo.log file.

Now I want to **redirect the output into the log file AND keep it on stdout**

i.e. it can be done trivially from outside the script:

    script | tee foo.log

but I want to do declare it within the script itself

I tried

    exec | tee foo.log

but it didn&#39;t work.

redirect COPY of stdout to log file from within bash script itself

Suppose I have the string `1:2:3:4:5` and I want to get its last field (`5` in this case). How do I do that using Bash? I tried `cut`, but I don&#39;t know how to specify the last field with `-f`.

How to split a string in shell and get the last field

I have a file contining some no of lines. I want split file into n no.of files with particular names. It doesn&#39;t matter how many line present in each file. I just want particular no.of files (say 5). here the problem is the no of lines in the original file keep on changing. So I need to  calculate no of lines then just split the files into 5 parts. If possible we have to send each of them into different directories.

How do I split a file into n no of parts

I want to split a data frame into several smaller ones. This looks like a very trivial question, however I cannot find a solution from web search.

How to split a data frame?

I have a list of product codes in a text file, on each line is the product code that looks like:

&gt; abcd2343 abw34324 abc3243-23A

So it is **letters** followed by **numbers** and **other characters**.

I want to **split** on the **first occurrence of a number**.

Product code looks like abcd2343, how to split by letters and numbers?

I am wondering if I am going about splitting a string on a `.` the right way? My code is: 

    String[] fn = filename.split(&quot;.&quot;);
    return fn[0];

I only need the first part of the string, that&#39;s why I return the first item. I ask because I noticed in the API that `.` means any character, so now I&#39;m stuck.

Content Type	Original Author	Original Content on Stackoverflow
Question	denormalizer	View Question on Stackoverflow
Solution 1 - Linux	academicRobot	View Answer on Stackoverflow

How to file split at a line number

Linux Problem Overview

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Are static members of a generic class tied to the specific instance?

When to use inherited tables in PostgreSQL?

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