Command-Line Syntax

All client applications as well as all of the Monitor Application’s built-in commands share the same command line parser for lexical analysis (i.e. tokenizing) and parsing command line arguments. While for most usual cases, the syntax is straight-forward, there are some corner cases and features to be aware of, especially if it comes to arguments with special characters, such as filenames that contain spaces.

Characters With Special Semantics

For the command-line parser, the following characters have special meaning:

• A white space character (“⠀”, ASCII #32 / 0x20) is interpreted as delimiter between two adjacent arguments, unless the white space character is escaped or appears within a string enclosed in double-quotes. Multiple adjacent white space delimiters are squashed into a single white space delimiter. White space character delimiters that are prefixed at the start of the command line or appended at the end of the line are ignored.
• The double-quote character (“"”, ASCII #34 / 0x22) is used to quote a sequence of characters by enclosing it with quotes. For example, imagine a filename arguments that contains a white space character. Without quoting, the white space in the filename would be interpreted as arguments delimiter, such that the tail of the filename would be cut off.
• Alternatively, a single white space character can also be quoted by escaping. A white space character is escaped by prefixing it with a backslash character (“\”, ASCII #92 / 0x5c).
• The backslash character itself can also be quoted by prefixing it with a backslash character. Escaping a backslash character is necessary e.g. when a backslash is to appear literally in a filepath.
• If the double-quote character is to literally appear as part of an enclosed string (rather than terminating it by being interpreted as closing quote), the double-quote character must be escaped by prefixing it with a backslash character.
• The hash character (“#”, ASCII #35 / 0x23) is interpreted as comment lead-in character for single-line comments, unless it appears within a quoted string or it is quoted with a backslash. Any characters on a command line, that appear after the comment lead-in, are ignored. Comments can be useful especially when authoring scripts for the monitor application.

Example

Suppose, in the monitor application, you want to pass the following filename as argument to the script command:

filename with spaces and "quotes".mon

Since this filename contains white spaces and quote characters, these characters would be treated specially rather than interpreted literally, as supposed. To avoid special treatment, but force literal interpretation, you could write:

script --file "filename with spaces and \"quotes\".mon"

Or:

script --file filename\ with\ spaces\ and\ \"quotes\".mon

Or even:

script --file filename\ wi"th spaces and \"qu"otes\".mon