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(slib.info)Command Line

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Command Line
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  `(require 'read-command)'

 - Function: read-command port
 - Function: read-command
     `read-command' converts a "command line" into a list of strings
     suitable for parsing by `getopt'.  The syntax of command lines
     supported resembles that of popular "shell"s.  `read-command'
     updates PORT to point to the first character past the command
     delimiter.

     If an end of file is encountered in the input before any
     characters are found that can begin an object or comment, then an
     end of file object is returned.

     The PORT argument may be omitted, in which case it defaults to the
     value returned by `current-input-port'.

     The fields into which the command line is split are delimited by
     whitespace as defined by `char-whitespace?'.  The end of a command
     is delimited by end-of-file or unescaped semicolon (<;>) or
     <newline>.  Any character can be literally included in a field by
     escaping it with a backslach (<\>).

     The initial character and types of fields recognized are:
    `\'
          The next character has is taken literally and not interpreted
          as a field delimiter.  If <\> is the last character before a
          <newline>, that <newline> is just ignored.  Processing
          continues from the characters after the <newline> as though
          the backslash and <newline> were not there.

    `"'
          The characters up to the next unescaped <"> are taken
          literally, according to [R4RS] rules for literal strings
          (Note: Strings.).

    `(', `%''
          One scheme expression is `read' starting with this character.
          The `read' expression is evaluated, converted to a string
          (using `display'), and replaces the expression in the returned
          field.

    `;'
          Semicolon delimits a command.  Using semicolons more than one
          command can appear on a line.  Escaped semicolons and
          semicolons inside strings do not delimit commands.

     The comment field differs from the previous fields in that it must
     be the first character of a command or appear after whitespace in
     order to be recognized.  <#> can be part of fields if these
     conditions are not met.  For instance, `ab#c' is just the field
     ab#c.

    `#'
          Introduces a comment.  The comment continues to the end of
          the line on which the semicolon appears.  Comments are
          treated as whitespace by `read-dommand-line' and backslashes
          before <newline>s in comments are also ignored.

 - Function: read-options-file filename
     `read-options-file' converts an "options file" into a list of
     strings suitable for parsing by `getopt'.  The syntax of options
     files is the same as the syntax for command lines, except that
     <newline>s do not terminate reading (only <;> or end of file).

     If an end of file is encountered before any characters are found
     that can begin an object or comment, then an end of file object is
     returned.