Procedure

   kxtrct_c ( Extract a substring starting with a keyword ) 

   void kxtrct_c ( ConstSpiceChar       * keywd,
                   SpiceInt               termlen,
                   const void           * terms,
                   SpiceInt               nterms,
                   SpiceInt               worlen,
                   SpiceInt               sublen,
                   SpiceChar            * wordsq,
                   SpiceBoolean         * found,
                   SpiceChar            * substr     )

Abstract

   Locate a keyword in a string and extract the substring from
   the beginning of the first word following the keyword to the
   beginning of the first subsequent recognized terminator of a list.

Required_Reading

   None.

Keywords

   PARSING
   SEARCH

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   keywd      I   Word that marks the beginning of text of interest.
   termlen    I   Length of strings in string array `terms'.
   terms      I   Set of words, any of which marks the end of text.
   nterms     I   Number of terms.
   worlen     I   Declared length of string `wordsq'.
   sublen     I   Declared length of output string `substr'.
   wordsq    I-O  String containing a sequence of words.
   found      O   SPICETRUE if the keyword is found in the string.
   substr     O   String from end of `keywd' to beginning of first
                  `terms' item found.

Detailed_Input

   keywd       is a word used to mark the start of text of interest.

   termlen     is the maximum number of characters that can be
               accommodated in the each element of the input argument
               `terms'. This count includes room for the terminating null
               characters.

   terms       is a set of words, any one of which may signal the end of
               text of interest.

               The array `terms' should be declared with dimensions

                  [nterms][termlen]

   nterms      is the number of elements in the array `terms'.

   worlen      is the maximum number of characters that can be
               accommodated in the in/out argument `wordsq'. This count
               includes room for the terminating null character.
               For example, if the maximum allowed length of the
               output string, including the terminating null, is 25
               characters, then stringlen should be set to 25.

   sublen      is the maximum number of characters that can be
               accommodated in the output argument `substr'. This count
               includes room for the terminating null character.

   wordsq      is a character string made up of words, that may contain
               the keyword in `keywd'.

Detailed_Output

   wordsq      is the input string stripped of all words from the
               beginning of the keyword `keywd' to the end of the last
               word preceding one of the words in `terms' (or the end of
               the string if none of the `terms' follows `keywd' in the
               string).

   found       is a flag indicating whether `keywd' is present in the
               input `wordsq'. `found' is set to SPICETRUE if `keywd'
               is present and SPICEFALSE otherwise.

   substr      is the substring that begins with the first word
               following `keywd' up to the beginning of any of the
               words in `terms' or the end of the string. If no words
               are found between the keyword and the next terminator,
               `substr' is returned empty.

               `substr' cannot overwrite `wordsq'.

Parameters

   None.

Exceptions

   1)  If the `keywd' input string pointer is null, the error
       SPICE(NULLPOINTER) is signaled.

   2)  If the `keywd' input string has zero length, the error
       SPICE(EMPTYSTRING) is signaled.

   3)  If the `substr' output string pointer is null, the error
       SPICE(NULLPOINTER) is signaled.

   4)  If the `substr' output string has length less than two
       characters, the error SPICE(STRINGTOOSHORT) is signaled, since
       the output string is too short to contain one character of
       output data plus a null terminator.

   5)  If any of the `terms' or `wordsq' input array pointers is
       null, the error SPICE(NULLPOINTER) is signaled.

   6)  If any of the `terms' or `wordsq' input arrays' strings have
       length less than two characters, the error
       SPICE(STRINGTOOSHORT) is signaled.

   7)  If memory cannot be allocated to create the temporary variable
       required for the execution of the underlying Fortran routine,
       the error SPICE(MALLOCFAILED) is signaled.

Files

   None.

Particulars

   Definitions:

      A WORD     is a set of consecutive non-blank characters
                 delimited by blanks or either end of the string
                 that contains them.

   Given a string and a keyword this routine locates the first
   occurrence of the keyword in the string and returns the
   substring between the end of the keyword and the first occurrence
   of any of the words in a list of terminating words. If none
   of the terminating words follows the keyword in the string,
   the routine returns all of the string following the keyword.

   If the next word following the keyword is a terminating word,
   the substring returned will be empty.

   If the keyword can not be located in the string, the variable
   found will be returned as SPICEFALSE and the input string will be
   unchanged. The substring will be returned empty.

   In all other cases, the part of the input string from the
   beginning of the keyword to the start of the first terminating
   word will be removed. If no terminating word follows the keyword
   the portion of the string from the keyword to the last non-blank
   character of the string will be removed.

Examples

   Example 1.
   ----------
     Input:  wordsq  "FROM 1 October 1984 12:00:00 TO 1 January 1987"
             keywd   "TO"
             terms   "FROM"
                     "TO"
                     "BEGINNING"
                     "ENDING"

     Output: wordsq  "FROM 1 October 1984 12:00:00"
             found   SPICETRUE
             substr  "1 January 1987"



   Example 2.
   ----------
     Input:  wordsq  "FROM 1 October 1984 12:00:00 TO 1 January 1987"
             keywd   "FROM"
             terms   "FROM"
                     "TO"
                     "BEGINNING"
                     "ENDING"

     Output: wordsq  " TO 1 January 1987"
             found   SPICETRUE
             substr  "1 October 1984 12:00:00"



   Example 3.
   ----------
     Input:  wordsq  "ADDRESS: 4800 OAK GROVE DRIVE PHONE: 354-4321 "
             keywd   "ADDRESS:"
             terms   "ADDRESS:"
                     "PHONE:"
                     "NAME:"

     Output: wordsq  " PHONE: 354-4321"
             found   SPICETRUE
             substr  "4800 OAK GROVE DRIVE"


   Example 4.
   ----------
     Input:  wordsq  "ADDRESS: 4800 OAK GROVE DRIVE PHONE: 354-4321 "
             keywd   "NAME:"
             terms   "ADDRESS:"
                     "PHONE:"
                     "NAME:"

     Output: wordsq  "ADDRESS: 4800 OAK GROVE DRIVE PHONE: 354-4321"
             found   SPICEFALSE
             substr  ""

Restrictions

   1)  It is the user's responsibility to make sure there is adequate
       room in `substr' to contain the substring.

   2)  `substr' cannot overwrite `wordsq'.

Literature_References

   None.

Author_and_Institution

   N.J. Bachman        (JPL)
   J. Diaz del Rio     (ODC Space)
   H.A. Neilan         (JPL)
   W.L. Taber          (JPL)

Version

   -CSPICE Version 1.1.0, 03-AUG-2021 (JDR)

       Changed the argument names "stringlen", "substrlen" and "string" to
       "worlen", "sublen" and "wordsq" for consistency with other routines.

       Edited the header to comply with NAIF standard. Added -Restrictions
       section.

       Added entry #7 to -Exceptions section.

   -CSPICE Version 1.0.0, 18-AUG-2002 (NJB) (HAN) (WLT)

Index_Entries

   extract a substring starting with a keyword