I wants to check on my linux system when which command was fired - at which date and time.

I fired commands like this:

    history 50 

It shows me the last 50 commands history, but not with date and time at which it was fired. Does any one knows how to do it?


Linux Command History with date and time

Using [Chris&#39;s answer](https://stackoverflow.com/questions/3147097/how-to-prepend-the-past-to-a-git-repository/3148117#3148117) on another question I could prepend a snapshot-history to my git repository. Since one of the files is not part of my history but only in the snapshots, the first original commit now also contains the deletion of this file. How can I undo that?

*At first I thought this was the opposite of [How do I remove sensitive files from git’s history](https://stackoverflow.com/questions/872565/how-do-i-remove-sensitive-files-from-gits-history), but actually I don&#39;t want to insert a file into history but just remove the deletion from history.*

How to undelete a file previously deleted in git&#39;s history?

I was told that in ZSH you could do something like `command` and then when you hit up it would filter the history based on the given command. But when I try this it just cycles the history like bash does. Is this disabled by default?

Filtering ZSH history by command

I want to take a function out of one file and put it into another, but keep the blame history.

    cp a.php b.php

    vim b.php
    # delete everything but 1 function

    vim a.php
    # delete the 1 function

    git add a.php b.php
    git commit

But if I run `git blame b.php` I only see it blaming to this new commit.

Keep git history when splitting a file

I&#39;m trying to prevent `bash` from saving duplicate commands to my history. Here&#39;s what I&#39;ve got:

    shopt -s histappend
    export HISTIGNORE=&#39;&amp;:ls:cd ~:cd ..:[bf]g:exit:h:history&#39;
    export HISTCONTROL=erasedups
    export PROMPT_COMMAND=&#39;history -a&#39;

This works fine while I&#39;m logged in and `.bash_history` is in memory. For example:

    $ history
        1 vi .bashrc
        2 vi .alias
        3 cd /cygdrive
        4 cd ~jplemme
        5 vi .bashrc
        6 vi .alias
    
    $ vi .bashrc
    
    $ history
        1 vi .alias
        2 cd /cygdrive
        3 cd ~jplemme
        4 vi .alias
        5 vi .bashrc
    
    $ vi .alias
    
    $ history
        1 cd /cygdrive
        2 cd ~jplemme
        3 vi .bashrc
        4 vi .alias
    
    $ exit

But when I log back in, my history file looks like this:

    $ history
        1 vi .bashrc
        2 vi .alias
        3 cd /cygdrive
        4 cd ~jplemme
        5 vi .bashrc
        6 vi .alias
        7 vi .bashrc
        8 vi .alias

What am I doing wrong?

EDIT: Removing the `shopt` and `PROMPT_COMMAND` lines from `.bashrc` does not fix the problem.

Prevent duplicates from being saved in bash history

In the course of my reading I came accross [WG14 Defect Report #51](http://www.open-std.org/jtc1/sc22/wg14/www/docs/dr_051.html) written in 1993 (or perhaps 1893, they left off the century and millennium). In the code sample there, apparently an operator spelled `-&gt;&gt;` is used on a pointer to a `struct`. I can&#39;t find it in any operator precedence tables I&#39;ve found, so I am wondering, is or was it ever an operator, and if so, what does (or did, as the case may be) this operator do?

At first I thought it was a typo, but it is reproduced twice more in the text and another time in the code sample in the response to the question, and I have a hard time believing it just slipped past at least two C experts without being noticed, when it jumped out at a novice like me. It&#39;s also at the focal point of the code, very easy to notice, and was never corrected.

Here is the code with added indentation:

    #include &lt;stdlib.h&gt;
    
    struct A {
        char x[1];
    };
    
    main()
    {
        struct A *p = (struct A *) malloc(sizeof(struct A) + 100);
        p-&gt;&gt;x[5] = &#39;?&#39;;  /* This is the key line [for both them and us] */
        return 0;
    }

I tried to compile this code with both a C and C++ compiler and it failed to parse in either one. Perhaps this was some operator in an early version of C that isn&#39;t used any more?

This feels suspiciously like the [What is the name of this operator: &quot;--&gt;&quot;?](https://stackoverflow.com/questions/1642028/what-is-the-name-of-this-operator) question, but I don&#39;t think this is a combination of two other operators, I don&#39;t see how it can be divided up and be valid.

Is this -&gt;&gt; an old operator or a typo/error?

Using nginx, I want to preserve the url, but actually load the same page no matter what.  I will use the url with `History.getState()` to route the requests in my javascript app.  It seems like it should be a simple thing to do?

    location / {
        rewrite (.*) base.html break;
    }

works, but redirects the url?  I still need the url, I just want to always use the same page.

nginx: send all requests to a single html page

So I found the question about how to view the change history of a file, but the change history of this particular file is huge and I&#39;m really only interested in the changes of a particular method. So would it be possible to see the change history for just that particular method?

I know this would require git to analyze the code and that the analysis would be different for different languages, but method/function declarations look very similar in most languages, so I thought maybe someone has implemented this feature.

The language I&#39;m currently working with is Objective-C and the SCM I&#39;m currently using is git, but I would be interested to know if this feature exists for any SCM/language.

Git - how do I view the change history of a method/function?

&#39;`hello, world`&#39; is usually the first example for any programming language. I&#39;ve always wondered where this sentence came from and where was it first used.

I&#39;ve once been told that it was the first sentence ever to be displayed on a computer screen, but I&#39;ve not been able to find any reference to this.

So my question is:  
Where does the practice to use &#39;`hello, world`&#39; as the first example for computer languages originate from?  
Where was it first used?

**Update**  
Although the answers are quite interesting, I should have noted that I had read the Wikipedia article. It does answer the question about the first use in literature, but does not answer when &#39;`hello world`&#39; was first *used*.  
So I think that it is safe to conclude that it was not the first sentence ever to be displayed on a computer screen and that there is no record about when it was first used?


Where does &#39;Hello world&#39; come from?

I know that in the architectures I&#39;m personally familiar with (x86, 6502, etc), the stack typically grows downwards (i.e. every item pushed onto the stack results in a decremented SP, not an incremented one). 

I&#39;m wondering about the historical rationale for this. I know that in a unified address space, it&#39;s convenient to start the stack on the opposite end of the data segment (say) so there&#39;s only a problem if the two sides collide in the middle. But why does the stack traditionally get the top part? Especially given how this is the opposite of the &quot;conceptual&quot; model?

(And note that in the 6502 architecture, the stack also grows downwards, even though it is bounded to a single 256-byte page, and this direction choice seems arbitrary.)

Why do stacks typically grow downwards?

I understand it&#39;s off topic, I couldn&#39;t find anywhere online and I was thinking maybe programming gurus in the community might know this.  
I usually use 

    kill -9 pid

to kill the job. I always wondered the origin of 9. I looked it up online, and it says

&quot;9 Means KILL signal that is not catchable or ignorable. In other words it would signal process (some running application) to quit immediately&quot; (source: http://wiki.answers.com/Q/What_does_kill_-9_do_in_unix_in_its_entirety)

But, why 9? and what about the other numbers? is there any historical significance or because of the architecture of Unix?


Why number 9 in kill -9 command in unix?

Recently I had to run a command that unfortunately required me to type a password right on the command line.

Afterwards, I cleared my screen with &quot;Clear&quot;, but also wanted to clear the command history so the offending command wouldn&#39;t show up in the session history. Unfortunately, the [Clear-History][1] cmdlet doesn&#39;t seem to actually do what its documentation claims - running Clear-History doesn&#39;t seem to have any impact on the session history whatsoever.

I can still see previous commands in the pop-up history menu, and scroll through old commands by pressing the up key. Here&#39;s a screengrab demonstrating the problem:

![PowerShell clear history failure][2]

I&#39;ve verified with [Get-Command][3] that Clear-History is indeed executing the expected built-in PowerShell cmdlet.

I&#39;ve tried a few variations, such as &quot;Clear-History -count 10 -newest&quot;, all failing to show any effect. When I specify an exact history ID, such as &quot;Clear-History -id 3&quot;, I receive an error like this:

    Clear-History : Cannot locate history for Id 3.

Even if I can see command #3 on the screen.

  [1]: https://docs.microsoft.com/en-us/powershell/module/Microsoft.PowerShell.Core/Clear-History
  [2]: http://i.stack.imgur.com/C9tDQ.png
  [3]: https://docs.microsoft.com/en-us/powershell/module/Microsoft.PowerShell.Core/Get-Command



PowerShell&#39;s Clear-History doesn&#39;t clear history

I&#39;ve renamed a couple of files using `git mv`, used `git stash`, had a quick look at HEAD (without changing it) then did `git stash pop` to get the whole lot back again. My moves had disappeared from the commit list, so I redid them with `git rm` and the commit message claimed git had spotted the rename was a rename. So I thought no more of it.

But now, post-commit, I can&#39;t get at the history of the moved files! Here&#39;s what git says about the commit in question:

    ~/projects% git log --summary
    commit de6e9fa2179ae17ec35a5c368d246f19da27f93a
    Author: brone
    Date:   Wed Dec 8 22:37:54 2010 +0000
    
        Moved R_DebugUI into runtime
    
     delete mode 100644 test/R_DebugUI_iOS.h
     delete mode 100644 test/R_DebugUI_iOS.m
     create mode 100644 system/runtime/src/R_DebugUI_iOS.h
     create mode 100644 system/runtime/src/R_DebugUI_iOS.m

     &lt;&lt;snip older commits&gt;&gt;
     ~/projects%

I&#39;m now trying to get the history of one of these moved files, so I can look at an old version, but I don&#39;t get anything very useful:

    ~/projects/system/runtime/src% git log --follow --find-copies-harder -M -C R_DebugUI_iOS.m
    commit de6e9fa2179ae17ec35a5c368d246f19da27f93a
    Author: brone
    Date:   Wed Dec 8 22:37:54 2010 +0000
    
        Moved R_DebugUI into runtime
    ~/projects/system/runtime/src% 

(I&#39;ve also tried it without `-M`, `-C` and `--find-copies-harder`, but to no avail.)

I can get its history under its old name, which stops at the point it was deleted from its old location:

    ~/projects% git log --summary --follow --find-copies-harder -M -C -- test/R_DebugUI_iOS.m
    commit de6e9fa2179ae17ec35a5c368d246f19da27f93a
    Author: brone
    Date:   Wed Dec 8 22:37:54 2010 +0000
    
        Moved R_DebugUI into runtime
    
     delete mode 100644 test/R_DebugUI_iOS.m
    
    commit 32a22d53c27e260714f759ecb3d3864e38b2e87f
    Author: brone
    Date:   Tue Dec 7 23:52:51 2010 +0000
    
        Can set debug UI&#39;s alpha.
    
    &lt;&lt;snip older commits&gt;&gt;
    ~/projects%

So I&#39;m not completely stuck this time, but I wouldn&#39;t fancy having to do this kind of thing all the time. (I anticipate having a fair number of files that will move at least once in their life.)

Am I doing something wrong? The old copy of the file and the new copy are 98.8% the same (2 lines out of 166 changed). My understanding is that git should be able to track the file in this case, because it infers rename operations rather than storing them explicitly, and the files are similar enough that I believe it should consider them the same.

Is there anything I can do to fix this?


Why might git log not show history for a moved file, and what can I do about it?

I am curious about the original purpose of the `&lt;input type=&quot;hidden&quot;&gt;` tag.

Nowadays it is often used together with JavaScript to store variables in it which are sent to the server and things like that.

- HTML 2.0 was released in [November 1995][1], containing already the [specification for input type=&quot;hidden&quot;][2]
- JavaScript was released [March 1996][3]

Therefore, the `&lt;input type=&quot;hidden&quot;&gt;` existed **before** JavaScript, so what was its original purpose? I can only imagine of sending a value from the server to the client which is (unchanged) sent back to maintain a kind of a state. Or do I get something wrong in the history of it and `&lt;input type=&quot;hidden&quot;&gt;` was always supposed to be used together with JavaScript?

If possible, please also give references in your answers.


  [1]: http://en.wikipedia.org/wiki/HTML#HTML_version_timeline
  [2]: http://www.w3.org/MarkUp/html-spec/html-spec_8.html#SEC8.1.2.6
  [3]: http://en.wikipedia.org/wiki/JavaScript#Version_history

Original purpose of &lt;input type=&quot;hidden&quot;&gt;?

When I run `history` in Bash, I get a load of results (1000+). However, when I run `history` the zsh shell I only get 15 results. This makes grepping history in zsh mostly useless. 
My `.zshrc` file contains the following lines:

    HISTFILE=~/.zhistory
    HISTSIZE=SAVEHIST=10000
    setopt sharehistory
    setopt extendedhistory

How can I fix zsh to make my shell history more useful?


----------

UPDATE

If in zsh I call `history 1` I get all of my history, just as I do in Bash with `history`. I could alias the command to get the same result, but I wonder why does `history` behave differently in zsh and in Bash.

zsh history is too short

All the time I read sentences like
&gt;don&#39;t rely on 1 byte being 8 bit in size
&gt;
&gt;use `CHAR_BIT` instead of 8 as a constant to convert between bits and bytes

et cetera. What real life systems are there today, where this holds true?
&lt;sub&gt;(I&#39;m not sure if there are differences between C and C++ regarding this, or if it&#39;s actually language agnostic. Please retag if neccessary.)&lt;/sub&gt;

System where 1 byte != 8 bit?

In 32bit, we had 8 &quot;general purpose&quot; registers. With 64bit, the amount doubles, but it seems independent of the 64bit change itself.  
Now, if registers are so fast (no memory access), why aren&#39;t there more of them naturally? Shouldn&#39;t CPU builders work as many registers as possible into the CPU? What is the logical restriction to why we only have the amount we have?

If registers are so blazingly fast, why don&#39;t we have more of them?

What sequence of events made Django the most popular Python web framework .. and still so? Even though several other frameworks exist.

**Note**: This question is **neither argumentative nor confrontational**. I merely asked for (objective) &quot;the sequence of events&quot; that lead to its actual popularity. Being aware of [the dynamics of software acceptance][1], I am not intending anyone to get into arguments over technical superiority.


  [1]: http://en.wikipedia.org/wiki/Worse_is_better

History of Django&#39;s popularity

I have never thought about until recently, but I&#39;m not sure why we call strings `strings`.  I am a .NET programmer, but I believe the concept of strings exist in virtually every programming language.

Outside of programming, I don&#39;t believe I&#39;ve heard the word `string` used to describe words or letters.  A quick Google of, &#39;Define: string&#39; yields a bunch of definitions that have nothing to do with the concept of letters, words, or anything of the nature associated to programming.

My guess of it, is that, back in the day, strings were really just arrays of characters of a particular length, often with a delimiting character at the end.  But, I don&#39;t see a natural transition from &#39;character array&#39; to `string`.

Can someone offer up some insight to why we call strings `strings`?  



The History Behind the Definition of a &#39;String&#39;

I am a C and C++ programmer and am now trying to learn C#. I have bought the book [Professional C#][1] by Wrox publications. 

While migrating from C to C++ I had a doubt why `++` was added to C. Later on I realized that since `++` is an increment operator and it was added to C just to provide an &#39;Object Oriented Extension&#39;.

In C#, what is the significance of `#`?



  [1]: http://www.amazon.com/Professional-2008-Wrox-Guides/dp/0470191376

Origin of the C# language name

Want to see last executed queries in MySql Workbench whether its 

&gt; create / alter table query 
&gt;
&gt; select / insert / update query 
or any query list.

in short want to see history of all queries

MySql workbench query history ( last executed query / queries ) i.e. create / alter table, select, insert update queries

I have a folder in my Git repository that I&#39;d like to move out in to its own repository. Is it possible to move the history of that folder along with the folder?

I&#39;ve previously been doing just a `git rm -r --cached subfolder/` and then `git init` on the subfolder. However, the history is not imported in to the new repository.

Export subtree in Git with history

What is the shortcut to search my command history in macOS terminal? 

For how long is the history available for searching? Where is it stored?


Searching your command history on macOS terminal

I&#39;ve read a dozen of times now that the state object could exists of multiple key|value pairs and that it is associated with the new history entry.
But could someone please give me an example of the benefits of the state object? Whats the practical use of it? I can&#39;t imagine why not just typing in {}

pushState: what exactly is the state object for?

I&#39;m getting this error in Firefox&#39;s Console: `SecurityError: The operation is insecure` and the guilty is HTML5 feature: `window.history.pushState()` when I try to load something with AJAX. It is supposed to load some data but Javascript stops executing on error.

I&#39;m wondering why this may be happening. Is this some server misconfiguration? Any help would be appreciated.

UPDATE: Yes, it was a server error with domain name not matching: http://en.wikipedia.org/wiki/Same-origin_policy

SecurityError: The operation is insecure - window.history.pushState()

Why does Internet Explorer has `Mozilla` in UserAgent?

In Firefox it&#39;s stating:

&gt;Mozilla/5.0 (Windows NT 6.1; rv:7.0.1) Gecko/20100101 Firefox/7.0.1

In Interner Explorer it&#39;s stating:

&gt;Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; Tablet PC 2.0; .NET4.0E; .NET4.0C)

In some blogs/forums it&#39;s mentioned, that it is due to some historical reasons, but what&#39;s the reason?

It would be very helpful to know about it.

Why does Internet Explorer (9) report &quot;Mozilla&quot; in UserAgent?

Many of you have seen [this graph][1] of Google Trends of popular AJAX frameworks (Dojo, jQuery, YUI).

The graph seems to make it clear that interest in Dojo collapsed in the second quarter of 2008, falling by 80%; jQuery picked up the slack and ultimately grew to more than triple the size of Dojo.

Why?  What happened in Q2 2008 that demolished interest in Dojo?

(Note that I&#39;m not really interested in a comparison of [Dojo vs. jQuery][2]; even if you can explain why one is better than the other, it&#39;s hard to see why that suddenly became clear to the world in April 2008.)


  [1]: http://www.google.com/trends?q=jquery%2Cdojo%2Cyui &quot;Google Trends: jquery,dojo,yui&quot;
  [2]: https://stackoverflow.com/questions/394601/which-javascript-framework-jquery-vs-dojo-vs &quot;Which Javascript framework (jQuery vs Dojo vs … )?&quot;

What happened to Dojo in 2008?

There are a variety of characters that are not legally encodeable in XML 1.0, e.g. `U+0007` (&#39;bell&#39;) and `U+001B` (&#39;escape&#39;). Most of the interesting ones are non-whitespace &#39;control&#39; characters.  

It&#39;s clear from (e.g.) [this question](https://stackoverflow.com/questions/209193/special-characters-in-xml) and others that it&#39;s &lt;a href=&quot;http://www.sklar.com/blog/archives/96-XML-vs.-Control-Characters.html&quot;&gt;the XML spec that&#39;s the issue&lt;/a&gt; -- but can anyone illuminate me as to *why* the XML spec forbids these characters? 

It seems like it could have been required that they be encoded in escapes, e.g. as `&amp;#x0007;` and `&amp;#x001B;` respectively, but perhaps there&#39;s a practical reason that the characters were forbidden rather than required to be escaped?

Answerers have suggested that there is some motivation towards avoiding transmission control characters, but Unicode includes many *other* control-like characters (consider `U+200C` &quot;zero width non joiner&quot;). I recognize there may be no good reason for this behavior, but I would still like to understand it better.

It&#39;s particularly frustrating because when those character values appear in other &lt;strike&gt;encodings&lt;/strike&gt; data formats, I end up &quot;double-escaping&quot; new XML documents that need to encode this.

Why are &quot;control&quot; characters illegal in XML 1.0?

Is there a way to get the SQL text for the last few queries?

I am using Microsoft SQL Server 2005

TSQL: Get Last Queries Ran

At times I want to revisit a change I committed to SVN a short while back, but don&#39;t recall the specific files involved or the revision number.  So I would like to see a list of recent commit messages, ideally including the files included in each commit.

I picture going to the root of my working copy and entering something like the following to see the messages and files associated with the most recent 5 commits:

    svn log -l5 -v *

Unfortunately, this command requires a single target, and won&#39;t accept &#39;*&#39;.  I know SVN has the information I want.  Is there a simple way to retrieve it?

How to get a list of all recent SVN commit messages?

How to see the **Check-In History of a particular** user in TFS (TFS-2008)?

How to see the Check-In History of a particular user in TFS?

I have a project under `git`. One day I moved all project files from current directory to `foo/bar/` under the project. I did it using `git mv`. Then I added some more files and did some changes to already existing files.

As a result, now when I look at the history of `foo/bar/file.c`, I can only see changes that I did after I moved the file.

I tried to fix this in various ways (`filter-branch` with subdirectory filter, etc), but nothing helped, so I am pretty stacked here. I&#39;ll appreciate any help that you can give me.
Thanks!

All History Solutions on Gang of Coders

Total of 32 History Solutions

Linux Command History with date and time

How to undelete a file previously deleted in git's history?

Filtering ZSH history by command

Keep git history when splitting a file

Prevent duplicates from being saved in bash history

Is this ->> an old operator or a typo/error?

nginx: send all requests to a single html page

Git - how do I view the change history of a method/function?

Where does 'Hello world' come from?

Why do stacks typically grow downwards?

Why number 9 in kill -9 command in unix?

PowerShell's Clear-History doesn't clear history

Why might git log not show history for a moved file, and what can I do about it?

Original purpose of <input type="hidden">?

zsh history is too short

System where 1 byte != 8 bit?

If registers are so blazingly fast, why don't we have more of them?

History of Django's popularity

The History Behind the Definition of a 'String'