Procedure

   SpiceInt ncposr_c ( ConstSpiceChar    * str,
                       ConstSpiceChar    * chars,
                       SpiceInt            start  )

Abstract

 
   Find the first occurrence in a string of a character NOT belonging
   to a collection of characters, starting at a specified location,
   searching in reverse.
 

Required_Reading

 
   SCANNING 
 

Keywords

 
   CHARACTER 
   SEARCH 
   UTILITY 
 

Brief_I/O

 
   VARIABLE  I/O  DESCRIPTION 
   --------  ---  -------------------------------------------------- 
   str        I   Any character string. 
   chars      I   A collection of characters. 
   start      I   Position to begin looking for one of chars. 
 
   The function returns the index of the last character of str 
   at or before index start that is not in the collection chars. 
 

Detailed_Input

 
   str        is any character string. 
 
   chars      is a character string containing a collection 
              of characters.  Spaces in chars are significant,
              including trailing blanks.  The order in which
              characters are listed is not significant.
 
   start      is the position in str to begin looking for one of 
              the characters in chars.  start may range from 0
              to n-1, where n is the number of characters in str.
 

Detailed_Output

 
   The function returns the index of the last character of str (at or
   before index start) that is not one of the characters in the string
   chars.  The returned value normally ranges from 0 to n-1, where n is
   the number of characters in str. If none of the characters is found,
   the function returns -1.
 

Parameters

 
   None. 
 

Exceptions

  
   1) The error SPICE(NULLPOINTER) is signaled if either of 
      the input string pointers is null.

   2) If start is less than 0, ncposr_c returns -1. 
 
   3) If start is greater than or equal to the length of the string, 
      the search begins at the last character of the string. 

   4) The function returns -1 if either of the input strings is empty.

Files

 
   None. 
 

Particulars

 
   ncposr_c is case sensitive. 
 
   An entire family of related CSPICE routines

      cpos_c
      cposr_c
      ncpos_c
      ncposr_c 
      pos_c
      posr_c 

   is described in the Required Reading. 
  

Examples

 
   Let string == "BOB, JOHN, TED, AND MARTIN...." 
                  012345678901234567890123456789
 
   Let chars  == "ABCDEFGHIJKLMNOPQRSTUVWXYZ" 

   Normal (sequential) searching: 
   ------------------------------ 

     ncposr_c( string, ' ,',    29 ) = 29 
     ncposr_c( string, ' ,',    28 ) = 28 
     ncposr_c( string, ' ,',    27 ) = 27 
     ncposr_c( string, ' ,',    26 ) = 26 
     ncposr_c( string, ' ,',    25 ) = 19 
     ncposr_c( string, ' ,',    18 ) = 15 
     ncposr_c( string, ' ,',    14 ) = 14 
     ncposr_c( string, ' ,',    13 ) = 10 
     ncposr_c( string, ' ,',     9 ) =  9 
     ncposr_c( string, ' ,',     8 ) =  4 
     ncposr_c( string, ' ,',     3 ) =  3 
     ncposr_c( string, ' ,',     2 ) = -1 
 

   start out of bounds: 
   -------------------- 

     ncposr_c( string, ' ,',    -1 ) = -1 
     ncposr_c( string, ' ,',    -5 ) = -1 
     ncposr_c( string, ' ,',    30 ) = 29 
     ncposr_c( string, ' ,',   122 ) = 29 
 

Restrictions

 
   None. 
 

Literature_References

 
   None. 
 

Author_and_Institution

 
   N.J. Bachman    (JPL) 
   W.L. Taber      (JPL) 
 

Version

 
   -CSPICE Version 1.0.0, 27-AUG-2002 (NJB) (WLT)

Index_Entries

 
   backward search for position of unlisted character 
 

Link to routine ncposr_c source file ncposr_c.c