Commands and Argument detection
Commands and arguments are the two smallest piece of code in batch and are used to describe a single operation the interpreter can execute.
Argument detection
What pBat considers to be arguments is a set characters delimited by delimiters accepted by pBat which are colons (;), semicolons (;), comma (,), newlines, tabs and spaces. Thus the following line consists of two arguments:
COMMAND foo bar
However, as it is quite common to need to pass arguments to commands that contain one of the preceding delimiters, It is possible to use either quotation marks (“) or character escaping via ^ to override delimiters default behaviour :
COMMAND "foo bar"
COMMAND foo^ bar
Both preceding syntax are valid. Note that if using quote, characters outside the quotes can be appended or be preceding without any influence on the validity of the line, just like the following.
COMMAND foo"ta fu"bar
Note that normal control character like |, & or ( and ) are ignored when surrounded by quotation marks.
Commands
Commands are the simplest structure of batch programming. Every action is done using a command. Commands are lines (or a part of line, if conditonnal operators are used), that denote an action to be done. Typically, commands are described using the following syntax :
COMMAND mandatory_argument [optional_argument] [choice1 | choice2]
Where:
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COMMAND is the name of the command. COMMAND should refer to one of the following possibilities, by order of precedence:
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An internal command to be ran, that is, a command which is included inside the pBat command interpreter.
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A path or the name of an external command located inside one of the directories listed in %PATH% variable if pBat fails to find an internal command matching COMMAND.
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If both preceding options fail, pBat considers that COMMAND refers to a file that is not executable and tries to find a program to handle COMMAND using operating systems files associations. The script used to find operating system associations under UNIX-derived OSes can be customized using %PBAT_START_SCRIPT% environment variable.
A list of commands shipped with pBat (internal and external) can be obtained through command list manual page.
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madatory_argument is an argument that must be specified for the command to run properly.
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Optional_argument is an argument that is not required by the command and is optional. These arguments only affect the behaviours of the command. Two arguments can be simultaneously optional is specified as:
COMMAND [arg1 arg2]In this case, arg1 and arg2 have to be both specified for the command to be executed. Obviously, when specifying optional parameters you should not use the square brackets ([ and ]), theses are just a way to depict optionality.
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[choice1|choice2] specify a choice that have to be made between choice1 and choice2. Usually, specifying one of them is not mandatory as square brackets depict optionality. Some can consider this syntax ambiguous and depict the necessity of making a choice not using brackets, like:
COMMANDE {choice1|choice2}No pBat command is supposed to use this syntax as it not required for well designed command to require the user to make a mandatory choice.