See: http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_07_01.html

I believe those aren&#39;t &quot;if switches&quot;, rather &quot;test switches&quot; (because you have to use them inside [] brackets.

But the difference is:

`[ -e FILE ]` True if FILE exists.

This will return **true** for both `/etc/hosts` and `/dev/null` and for directories.

`[ -f FILE ]` True if FILE exists and is a regular file.
This will return **true** for `/etc/hosts` and **false** for `/dev/null` (because it is not a regular file), and **false** for `/dev` since it is a directory.


```lang-none
$ man bash

       -e file
              True if file exists.
       -f file
              True if file exists and is a regular file.
```

A regular file is something that isn&#39;t a directory, symlink, socket, device, etc.


The if statement actually uses the program &#39;test&#39; for the tests. You could write if statements two ways:

    if [ -e filename ];

or

    if test -e filename;

If you know this, you can easily check the man page for &#39;test&#39; to find out the meanings of the different tests:

    man test

`-e` checks for *any* type of filesystem object; `-f` *only* checks for a regular file.

I have a folder that have a space in the middle, but have a webconfig file inside it. I want git to ignore the webconfig file but somehow it&#39;s not ignoring it because of the space in the folder. Anybody know how to work around this?

    My FolderName/Web.config

I tried to insert the `%20` in the middle but that did not help.

Thank you for your help.


gitignore ignore files within a folder that has whitespace in the middle

I was playing with cmd.exe, but in its help I didn&#39;t find any info, how to define arrays.

I have found, how to define simple variables:

    set a=10
    echo %a%

But, I want to create arrays, linked list etc...

So, does it able in cmd.exe ( I mean: does in cmd.exe exist any array keywords? )

I want to realize some algorithms as:

- bubble sort
- quick sort
- gnome sort

etc...

So, I also want to know, does Cmd.exe have references or instances, structs etc?

Cause its help not full in: /?

Could Cmd.exe be defined as full by Turing-Machine definition? ( Turing-Complete )

Arrays, linked lists and other data structures in cmd.exe (batch) script

There are two switches for the `if` condition which check for a file: `-e` and `-f`.

What is the difference between those two?


Difference between &#39;if -e&#39; and &#39;if -f&#39;

<p>There are two switches for the <code>if</code> condition which check for a file: <code>-e</code> and <code>-f</code>.</p>
<p>What is the difference between those two?</p>


I have a Bash variable, `$word`, which is sometimes a word or sentence, e.g.:

    word=&quot;tiger&quot;

Or:

    word=&quot;This is a sentence.&quot;

How can I make a new Bash variable which is equal to only the first letter found in the variable? E.g., the above would be:

    echo $firstletter
    t

Or:

    echo $firstletter
    T

How to obtain the first letter in a Bash variable?

I both love and hate writing Bash. I love that it&#39;s *so* streamlined for operating on files and working with processes (I agree with [this popular question](https://stackoverflow.com/questions/3637668/why-are-scripting-languages-e-g-perl-python-ruby-not-suitable-as-shell-lang) that it&#39;s way better in this regard than Python, Ruby, etc.), but I *hate* the syntax, particularly around conditionals, loops, etc.

(This is subjective, but I find it both confusing and annoying. E.g. `$var` when reading, but `var` when writing; writes silently fail if there are spaces around `=`; the double brackets in ifs when using regexp; double semicolons sometimes and single semicolons others; etc.)

As a huge fan of CoffeeScript, which compiles to JS, I&#39;ve been wondering: are there any languages that have the aesthetic/syntax of languages like Python/Ruby/CoffeeScript but which compile and run as Bash instead of one of those other runtimes?

E.g. I&#39;d love to be able to write mostly-Bash with just a bit simpler syntax:

    $AGGREGATE_FILENAME = &#39;allfiles.txt&#39;
    
    if not exists $AGGREGATE_FILENAME
        touch $AGGREGATE_FILENAME
    
    for $file in files/*
        cat $file &gt;&gt; $AGGREGATE_FILENAME
    
    switch $1
        case &#39;test&#39;
            run-tests
            echo &#39;Tests finished!&#39;
        case &#39;deploy&#39;
            echo &#39;Packaging...&#39;
            mv foo bar/
            deploy-bar

This is a super contrived example, and the syntax is a strawman (mostly inspired from CoffeeScript but keeping the essential Bash notions of first-class commands, separated from variables, and loose typing).

Anyway, just a question and food for thought. I&#39;d *love* to be able to write my scripts in something nicer than Bash. =) Thanks!

Are there any languages that compile to Bash?

I am using `rm` within a BASH script to delete many files. Sometimes the files are not present, so it reports many errors. I do not need this message. I have searched the man page for a command to make `rm` quiet, but the only option I found is `-f`, which from the description, &quot;ignore nonexistent files, never prompt&quot;, seems to be the right choice, but the name does not seem to fit, so I am concerned it might have unintended consequences.

- Is the `-f` option the correct way to silence `rm`? Why isn&#39;t it called `-q`?
- Does this option do anything else?

How to prevent rm from reporting that a file was not found?

I am wondering what&#39;s the easiest way to check if a program is executable  with bash, without executing it ? It should at least check whether the file has execute rights, and is of the same architecture (for example, not a windows executable or another unsupported architecture, not 64 bits if the system is 32 bits, ...) as the current system.


Check if a file is executable

I&#39;m learning to develop in Rails, and have discovered the power of `zsh`. However, for some of my other tasks, I wish to use normal `bash`.

Although they are the same, I just feel comfortable with the layout of `bash` in some situations.

How do I switch back and forth, or turn `zsh` on and off?

Switching from zsh to bash on OS X, and back again?

How can I use an inline `if` statement in JavaScript? Is there an inline `else` statement too?

Something like this:

    var a = 2;
    var b = 3;
    
    if(a &lt; b) {
        // do something
    }

How to write an inline IF statement in JavaScript?

I went looking through `Raphael.js`&#39;s source code to find out how he converted RGB values to HSB. I found out the function he did it in and I was in the process of converting it to Python when I bumped into this nice triple-nested ternary operator:

    H = (C == 0 ? null :
        V == r ? (g - b) / C :
        V == g ? (b - r) / C + 2 :
                 (r - g) / C + 4
        );

It threw me for a loop because Python doesn&#39;t have the same kind of ternary operator that Javascript does. I spent a while looking over it and eventually hashed this somewhat saner code (using only if/else) out of it:

    if (C == 0) {
    	H = null;
    } else {
    	if(V == r) {
    		H = (g - b) / C;
    	} else {
    		if(V == g) {
    			H = (b - r) / C + 2;
    		} else {
    			H = (r - g) / C + 4;
    		}
    	}
    }

Was my interpretation correct? I&#39;m only asking this because if it isn&#39;t correct, I&#39;m faced with a *lot* of debugging. So. Did I &quot;get it&quot;?

A somewhat painful triple-nested ternary operator

I would like to have the `echo` command executed when `cat /etc/passwd | grep &quot;sysa&quot;` is not true.

What am I doing wrong?

    if ! [ $(cat /etc/passwd | grep &quot;sysa&quot;) ]; then
            echo &quot;ERROR - The user sysa could not be looked up&quot;
            exit 2
    fi


How to make &quot;if not true condition&quot;?

I have a string that I load throughout my application, and it changes from numbers to letters and such. I have a simple `if` statement to see if it contains letters or numbers but, something isn&#39;t quite working correctly. Here is a snippet.

    String text = &quot;abc&quot;; 
    String number; 
    
    if (text.contains(&quot;[a-zA-Z]+&quot;) == false &amp;&amp; text.length() &gt; 2) {
        number = text; 
    }

Although the `text` variable does contain letters, the condition returns as `true`. The and `&amp;&amp;` should eval as both conditions having to be `true` in order to process the `number = text;` 



==============================

***Solution:*** 

I was able to solve this by using this following code provided by a comment on this question. All other post are valid as well!

What I used that worked came from the first comment. Although all the example codes provided seems to be valid as well!

    String text = &quot;abc&quot;; 
    String number; 
    
    if (Pattern.matches(&quot;[a-zA-Z]+&quot;, text) == false &amp;&amp; text.length() &gt; 2) {
        number = text; 
    }

Java String - See if a string contains only numbers and not letters

Which is the better and fastest methods : if or switch ?

    if(x==1){
      echo &quot;hi&quot;;
    } else if (x==2){
      echo &quot;bye&quot;;
    }

    switch(x){
      case 1
        ...
      break;
      default;
    } 

Content Type	Original Author	Original Content on Stackoverflow
Question	Ahatius	View Question on Stackoverflow
Solution 1 - Bash	Emil Vatai	View Answer on Stackoverflow
Solution 2 - Bash	jman	View Answer on Stackoverflow
Solution 3 - Bash	gitaarik	View Answer on Stackoverflow
Solution 4 - Bash	Ignacio Vazquez-Abrams	View Answer on Stackoverflow

Difference between 'if -e' and 'if -f'

Bash Problem Overview

Bash Solutions

Solution 1 - Bash

Solution 2 - Bash

Solution 3 - Bash

Solution 4 - Bash

Arrays, linked lists and other data structures in cmd.exe (batch) script

gitignore ignore files within a folder that has whitespace in the middle

Attributions