System Feature
command
Purpose
General command syntax
Aliases
Syntax
command [-<option> [-<option> [-<option> ...] ] ] [<argument> [<argument> [<argument> ...] ] ]
Options
<option>s dictate how the command will operate on arguments.
An <option> is specified by a single letter or a digit prepended by a dash (-). Several options
can be combined after a single dash. As an example, following are all valid ways of specifying options for
the lf (list files) command.
-r recursive - list files in subdirectories
-g go around errors
-t list file type
-c list file creation time
-a list file access time
-m list file modification time
-s list fle size
-n list file name
-n list file name)
-c -n list file creation time and file name)
-cn same as -c -n, list file creation time and file name
-s -cn list file size, file creation time and file name
-scn same as -s -cn, list file size, file creation time and file name
Arguments
<argument>s are objects on which the command will operate. They can be constants, file/directory names, paths,
URLs (web page addresses), etc. What type of an object a command expects, depends on the command.
The following are valid examples of <argument>s.
repro "C:/X.txt"
repro "X.txt"
repro "http://www.biterscripting.com/index.html"
len "abc\ndef"
len $s # assuming $s is declared as a str variable
An <argument> can be specified with a constant, variable, function call, inline command or an expression
containing any number of any of these. When using an expression, enclose it in parentheses. When using a
str constant, enclose it in double quotes.
In general, all commands accept <argument>s of type string (str). There are some exceptions to this rule -
echo and set commands.
Stream Input
Some commands, such as the repro (reproduce) command, read contents of the stream input and operate on
them in addition to the <argument>s. Stream input must always be a string (str).
Stream input can be redirected from variables, files, etc. Details on how to do this are available in help
topic 'input'.
If no redirection is specified, stream input is assumed to be empty by default.
Stream Output
Commands write their output to this stream.
Stream output can be redirected to variables, files, etc. Details on how to do this are available in help
topic 'output'.
If no redirection is specified, contents of stream output are written to the screen (except batch mode).
See the help topic 'batch' for details of batch mode.
Stream Error
Commands write errors encountered during execution to this stream.
Stream error can be redirected to variables, files, etc. Details on how to do this are available in help
topic 'error'.
If no redirection is specified, contents of stream error are written to the screen (except batch mode).
See the help topic 'batch' for details of batch mode.
Note that commands encounter two types of errors - errors encounterd during parsing, and, errors encountered
during execution. In interactive mode, parsing errors are written to the screen. In batch mode, parsing errors
are written to stream error.
Description
Five important aspects of a command are - options, arguments, stream input, stream output, and, stream error.
Command arguments are objects on which a command will operate.
Command options dictate how a command will operate.
Stream input provides an additional way of specifying input data to a command. A command will operate
on stream input in addition to the objects specified by arguments. Note that only some commands,
such as the repro (reproduce) command, accept stream input. Other commands ignore stream input.
Check the help page on a command to see if that command accepts or ignores stream input.
A command writes its output to stream output.
Execution errors encounterd by a command are written to stream error.
Restrictions
Valid Examples
See help pages for individual commands.
Invalid Examples
See help pages for individual commands.
See Also
input
output
error
lf
var
repro
echo
set
len
batch
|
© 2008-2010, biterScripting.com. All rights reserved.
biterScripting, biterScript, biterBrowser, biterScripting.com, FVA (Forward Variable Assignment) are trademarks of biterScripting.com. Is it biterScripting-compatible ? is a service mark of biterScripting.com.
Explorer, Unix, Windows are trademarks, service marks or other forms of intellectual property of their respective owners.
|