Aug 5, 2015 10:18 AM
This tutorial will cover:
I will try my best to answer any question and comment. If there are any mistakes in this post, please let me know.
FOR (Click to View)
For this tutorial, I will only be going over the most commonly used functions.
The for command is very versatile and complex.
It generally loops.
The /F switch is designed to be loop through files, however it will allow the for command to be as specific as possible.
Command syntax:
Explanation:
[1] - Options:
[2] - Variable
This single character is the initial variable to be referenced. If used with more than one token, each token can be reference in order lexicographically, starting from the variable.
[3] - Quotes
This part specifies what the character set represents.
Example Usage:
However, if usebackq is used, the following becomes relevant.
[4] - Character set
This is the character set to be parsed by the for command.
[5] - Action
This is what should be executed every loop. You may use the variables as specified by the options and variable.
Now let's put it all together.
Command Example Usage:
Output:
The /L switch is designed to loop across numbers.
Command Syntax:
Explanation:
[1] - Variable
This is the variable to be referenced throughout the action.
[2] - Initial Quantity
This is the initial quantity to be used.
[3] - Step
This is the quantity that the loop should increment every time.
[4] - Stopping Quantity
This is the quantity that should cause the loop to stop after the initial quantity is sufficiently incremented to this value, or above.
[5] - Action
This is the commands that should executed every loop. The variable may be referenced.
Now let's put it all together.
Command Example Usage:
This code has added all the numbers from 1 to 10.
As expected, the output is:
Important Things:
Pointers (Click to View)
Pointers are variables whose value contain the name of another variable.
Example Usage:
The previous code sets a variable, str (string), which contains the value "Hello World". Another variable, strp (string pointer), which contains the value "str", the name of the former variable, is set.
Taking apart the code, we see that during the first ECHO, we get the value of str, and is ECHO'd. During the second ECHO, the value of strp is gotten, str, and then that value of the variable with the name of str is gotten, and ECHO'd.
Next, we set the value of the variable whose name is stored in strp, str, to be equal to "Bye World". We then ECHO the value of str.
There are various uses for pointers.
Arrays (Click to View)
An array is a group of variables whose value can be easily accessed, usually by incrementing an index value, which is usually a variable.
Arrays share some key concepts with pointers.
Here is a example of a array containing 10 elements, each with a value of its own index:
We can then access each element like so:
You can also set multi-dimensional arrays like so:
This sets a 10x10 dimensional array.
Arrays generally have more use than pointers.
Multi-Threading (Click to View)
Multi-threading allows more than one process to be run at the same time (sort of). It is especially useful for non-blocking user interfaces.
The main command for multi-threading in batch is:
The only part about this command you need to know is [1]. The rest is not important to know.
This command will create a instance of CMD running the same batch file in the same window as the thread that started it.
[1] denotes arguments, and should be used in the same was as CALL parameters. These parameters will be available in the same way CALL functions are used.
Found this in my drafts somewhere, and so I decided to just finish it up and post it. Enjoy
- FOR
- Pointers
- Arrays
- Multi-Threading
I will try my best to answer any question and comment. If there are any mistakes in this post, please let me know.
FOR (Click to View)
FOR
For this tutorial, I will only be going over the most commonly used functions.
The for command is very versatile and complex.
It generally loops.
/F flag
The /F switch is designed to be loop through files, however it will allow the for command to be as specific as possible.
Command syntax:
Code
for /f "[1]" %%[2] in ([3][4][3]) do ([5])Explanation:
[1] - Options:
- delims
This option will set the deliminator.
The deliminator is the character (or characters, plural) to split the character set into individual tokens.
Example usage:
The previous example will mean the character set will be ONLY split when '[' or ']' is found. '[' and ']' are not included in the tokensCode"delims=[]"
Note: By default, delims are space and tab. New line is always a deliminator.
- tokens
This option specifies which tokens will be used or included
Example usage:
The previous example will mean tokens 1, 2, 3, 4, 6, and everything that follows will be used. Note that 5 is not included.Code"tokens=1,2-4,6,*"
- usebackq
This option changes the quotes.
[2] - Variable
This single character is the initial variable to be referenced. If used with more than one token, each token can be reference in order lexicographically, starting from the variable.
[3] - Quotes
This part specifies what the character set represents.
- Using double-quotes means the character set is a string.
- Using single-quotes means the character set is a command (or commands) to be executed. The command output will become the character set to be parsed.
- Using no quotes means the character set specifies a file (with path). The file plaintext will be become the character set to be parsed.
Example Usage:
Code
'ping google.com'However, if usebackq is used, the following becomes relevant.
- Using single-quotes means that the character set is a string.
- Using grave accent means the character set is a command (or commands) to be executed. The command output will become the character set to be parsed.
- Using no quotes means the character set specifies a file (with path). The file plaintext will be become the character set to be parsed.
[4] - Character set
This is the character set to be parsed by the for command.
[5] - Action
This is what should be executed every loop. You may use the variables as specified by the options and variable.
Now let's put it all together.
Command Example Usage:
Code
for /f "tokens=1-2 delims= " %%A in ("hello world") do (echo %%B)Output:
Code
world/L flag
The /L switch is designed to loop across numbers.
Command Syntax:
Code
for /l %%[1] in ([2],[3],[4]) do ([5])Explanation:
[1] - Variable
This is the variable to be referenced throughout the action.
[2] - Initial Quantity
This is the initial quantity to be used.
[3] - Step
This is the quantity that the loop should increment every time.
[4] - Stopping Quantity
This is the quantity that should cause the loop to stop after the initial quantity is sufficiently incremented to this value, or above.
[5] - Action
This is the commands that should executed every loop. The variable may be referenced.
Now let's put it all together.
Command Example Usage:
Code
set sum=0
for /l %%A in (1,1,10) do (set /a sum+=%%A)
echo %sum%This code has added all the numbers from 1 to 10.
As expected, the output is:
Code
55Important Things:
- Since the action portion is commonly surrounded by parenthesis, you must use variables with delayed expansion if the variable will change throughout the loop, or something unexpected, interesting, and frustrating will surely happen.
Pointers (Click to View)
Pointers
Pointers are variables whose value contain the name of another variable.
Example Usage:
Code
set "str=Hello World"
set strp=str
echo %str%
echo !%strp%!
set "!strp!=Bye World"
echo !str!Taking apart the code, we see that during the first ECHO, we get the value of str, and is ECHO'd. During the second ECHO, the value of strp is gotten, str, and then that value of the variable with the name of str is gotten, and ECHO'd.
Next, we set the value of the variable whose name is stored in strp, str, to be equal to "Bye World". We then ECHO the value of str.
There are various uses for pointers.
Arrays (Click to View)
Arrays
An array is a group of variables whose value can be easily accessed, usually by incrementing an index value, which is usually a variable.
Arrays share some key concepts with pointers.
Here is a example of a array containing 10 elements, each with a value of its own index:
Code
for /l %%A in (1,1,10) do (
set array%%A=%%A
)We can then access each element like so:
Code
for /l %%A in (1,1,10) do (
echo !array%%A!
)You can also set multi-dimensional arrays like so:
Code
for /l %%A in (1,1,10) do (
for /l %%B in (1,1,10) do (
set array%%A.%%B=%%A.%%B
))Arrays generally have more use than pointers.
Multi-Threading (Click to View)
Multi-Threading
Multi-threading allows more than one process to be run at the same time (sort of). It is especially useful for non-blocking user interfaces.
The main command for multi-threading in batch is:
Code
start "" /b /d %cd% cmd /c ""%~0" [1]"The only part about this command you need to know is [1]. The rest is not important to know.
This command will create a instance of CMD running the same batch file in the same window as the thread that started it.
[1] denotes arguments, and should be used in the same was as CALL parameters. These parameters will be available in the same way CALL functions are used.
Found this in my drafts somewhere, and so I decided to just finish it up and post it. Enjoy
