Windows Batch Scripting - Wikibooks, open books for an open world. This book describes the Microsoft- supplied command interpreter on Windows NT, Windows XP, Windows Vista, Windows 7 and later, which is cmd. Introduction[edit]This book addresses 3. Windows commands applicable to modern versions of Windows based on the Windows NT environment. It does not address commands that are specific to DOS environments and to DOS- based operating systems, such as Windows 9.
Windows 9. 8, and Windows Me, whose Microsoft- supplied command interpreters are in fact DOS programs, not Win. You can find out which version of cmd. VER command. This book first describes using the Windows NT command interpreter, how it receives, parses, and processes commands from users. Then it describes various commands available.
- The Command Prompt in Windows 7 provides access to over 230 commands! The commands available in Windows 7 are used to automate processes, create batch files, and.
- In the past, we compiled the list of commands for the CMD command-line interpreter in Microsoft Windows, you can take a look at it below: Also Read: The Ultimate A to.
To obtain an extensive list of Windows commands and their short summaries, open the command prompt on any Windows computer, and type help. To find out about a particular command, type the name of the command followed by "/?". The subject of this book is also known as "batch programming", even though "batch" refers not only to batch files for MS DOS and Windows command interpreter. Other subject terms include "batch file programming", "batch file scripting", "Windows batch command", "Windows batch file", "Windows command line", "Windows command prompt", and "Windows shell scripting". Using the Windows command interpreter[edit]How a command line is interpreted[edit]The parsing of a command line into a sequence of commands is complex, and varies subtly from command interpreter to command interpreter. There are, however, four main components: Variable substitution.
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A command line is scanned for variable specifications, and any found are replaced with the contents of those variables. Quoting. Special characters can be quoted, to remove their special meanings. Syntax. Command lines are developed into a sequence of commands according to a syntax. Redirection. Redirection specifications are applied, and removed from the command line, before an individual command in a sequence is executed.
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Variable substitution[edit]Command lines can contain variable specifications. These comprise a % character followed by a name, followed by a second % character unless the name is a digit in 0 .. Variable specifications are replaced with values as follows: %varname%, such as %PATH% or %USERNAME%, is replaced with the value of the named environment variable. For example, %PATH% is replaced by the value of the PATH environment variable. %n for 0 < = n < = 9, such as %0 or %9, is replaced with is the value of the n- th parameter passed to the batch file when it was invoked, subject to any subsequent modifications by the SHIFT command. For example: %2 is replaced by the value of the second batch file parameter. %* is replaced with the values of all the command- line parameters except for %0, even those beyond index 9. SHIFT command has no impact on the result of %*.
See also Command- line arguments. Special names[edit]Some variable names are not visible using SET command. Rather, they are made available for reading using the % notation. To find out about them, type "help set". Special variable names and what they expand to: Name. Replacement Value Used %CD%The current directory, not ending in a slash character if it is not in the root directory of the current drive %TIME%The system time in HH: MM: SS. DATE%The system date in a format specific to localization. %RANDOM%A generated pseudo- random number between 0 and 3.
ERRORLEVEL%The error level returned by the last executed command, or by the last called batch script. %CMDEXTVERSION%The version number of the Command Processor Extensions currently used by cmd. CMDCMDLINE%The content of the command line used when the current cmd.
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Links: Quoting and escaping[edit]You can prevent the special characters that control command syntax from having their special meanings as follows, except for the percent sign (%): You can surround a string containing a special character by quotation marks. You can place caret (^), an escape character, immediately before the special characters. In a command located after a pipe (|), you need to use three carets (^^^) for this to work. The special characters that need quoting or escaping are usually < , > , |, & , and ^.
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In some circumstances, ! A newline can be escaped using caret as well. When you surround the string using quotation marks, they become part of the argument passed to the command invoked. By contrast, when you use caret as an escape character, the caret does not become part of the argument passed.
The percent sign (%) is a special case. On the command line, it does not need quoting or escaping unless two of them are used to indicate a variable, such as %OS%. But in a batch file, you have to use a double percent sign (%%) to yield a single percent sign (%).
Enclosing the percent sign in quotation marks or preceding it with caret does not work. Examplesecho "Johnson & son". Echoes the complete string rather than splitting the command line at the & character. Quotes are echoed as wellecho Johnson ^& son. As above, but using caret before the special character ampersand. No quotes are echoed.
Johnson & son. Does not use an escape character and therefore, "son" is interpreted as a separate command, usually leading to an error message that command son is not found. A ^^ B. Echoes A ^ B. Caret needs escaping as well or else it is interpreted as escaping a space. NUL | echo A ^^^^ B.
Echoes A ^ B. When after a pipe, a caret used for escaping needs to be tripled to work; the fourth caret is the one being escaped. Equal & ^echo Indeed, equal. Echoes the two strings. The caret at the end of the line escapes the newlines, leading to the three lines being treated as if they were a single line. The space before the first caret is necessary or else 1 gets joined with the following echo to yield 1echo. File^ 1. txt. Does not show attributes of file named "File 1.
Using quotes, as in attrib "File 1. The ratio was 4. 7%. If run from a batch, the percent sign is ignored.
The ratio was 4. 7%%. If run from a batch, the percent sign is output once. If run from a batch, sets modulo variable to 2, the remainder of dividing 1. Does not work with single %.
If run from a batch, outputs 1, 2 and 3. Outputs the content of temp variable even if run from a batch file. Use of the percent sign in a batch to access environment variables and passed arguments needs no escaping. Outputs literally %temp% when run from the command line. Outputs literally %temp% when run from a batch. Command FINDSTR uses backslash (\) for escaping.
Unlike caret, this is internal to the command and unknown to the command shell. Links: Command lines are developed into a sequence of commands according to a syntax. In that syntax, simple commands may be combined to form pipelines, which may in turn be combined to form compound commands, which finally may be turned into parenthesized commands. A simple command is just a command name, a command tail, and some redirection specifications.
An example of a simple command is dir *. A pipeline is several simple commands joined together with the "pipe" metacharacter—"|", also known as the "vertical bar".
The standard output of the simple command preceding each vertical bar is connected to the standard input of the simple command following it, via a pipe. The command interpreter runs all of the simple commands in the pipeline in parallel. An example of a pipeline (comprising two simple commands) is dir *.
A compound command is a set of pipelines separated by conjunctions. The pipelines are executed sequentially, one after the other, and the conjunction controls whether the command interpreter executes the next pipeline or not. An example of a compound command (comprising two pipelines, which themselves are just simple commands) is move file.
The conjunctions: & - An unconditional conjunction. The next pipeline is always executed after the current one has completed executing.& & - A positive conditional conjunction. The next pipeline is executed if the current one completes executing with a zero exit status.|| - A negative conditional conjunction.
The next pipeline is executed if the current one completes executing with a non- zero exit status. A parenthesized command is a compound command enclosed in parentheses (i.
From the point of view of syntax, this turns a compound command into a simple command, whose overall output can be redirected.