C_Strings

 String values in the C language are terminated with null characters
 (CHAR(0)) and can contain nonprintable characters (such as a
 backspace).

 Nonprintable characters are specified by escape sequences.  An
 escape sequence is denoted by using the backslash (\) as an escape
 character, followed by a single character indicating the
 nonprintable character desired.

 This type of string is specified by using a standard string
 constant followed by the character C.  The standard string constant
 is then interpreted as a C-language constant.  Backslashes are
 treated as escapes, and a null character is automatically appended
 to the end of the string (even if the string already ends in a null
 character).

 The following C-style escape sequences are allowed in character
 constants:

    Escape Sequence      Represents
    ---------------      ----------
    \a or \A             A bell
    \b or \B             A backspace
    \f or \F             A formfeed
    \n or \N             A new line
    \r or \R             A carriage return
    \t or \T             A horizontal tab
    \v or \V             A vertical tab
    \x"hh" or \X"hh"     A hexadecimal bit pattern
    \"ooo"               An octal bit pattern
    \0                   A null character
    \\                   A backslash 

 If a character constant contains any other escape sequence, the
 backslash is ignored.

 A C string must also be a valid Fortran string.  If the string is
 delimited by apostrophes, apostrophes in the string itself must be
 represented by two consecutive apostrophes ('').

 For example, the escape sequence \'string causes a compiler error
 because Fortran interprets the apostrophe as the end of the string.
 The correct form is \''string.

 If the string is delimited by quotation marks, quotation marks in
 the string itself must be represented by two consecutive quotation
 marks ("").

 The sequences \"ooo" and \x"hh" allow any ASCII character to be
 given as a one- to three-digit octal or a one- to two-digit
 hexadecimal character code.  Each octal digit must be in the range
 0 to 7, and each hexadecimal digit must be in the range 0 to F.
 For example, the C strings '\010'C and '\x08'C) both represent a
 backspace character followed by a null character.

 The C string '\\abcd'C) is equivalent to the string '\abcd' with a
 null character appended.  The string ''C represents the ASCII null
 character.