index(3)               C LIBRARY FUNCTIONS               index(3)



NAME
     index, rindex - string operations

SYNOPSIS
     #include <string.h>
     char *index(s, c)
     char *s, c;
     char *rindex(s, c)
     char *s, c;

DESCRIPTION
     These functions operate on NULL-terminated strings.  They do
     not  check  for overflow of any receiving string.  index and
     rindex returns a pointer to the first (last)  occurrence  of
     character  c  in  string  s, or a NULL pointer if c does not
     occur in the  string.   The  NULL  character  terminating  a
     string is considered to be part of the string.

SEE ALSO
     bstring(3), strings(3) malloc(3C) in the Programmer's Refer-
     ence Manual.

NOTES
     For user convenience, these functions are  declared  in  the
     optional  <strings.h>  header file. On the Sun processor, as
     well as on many other machines,  you  can  not  use  a  NULL
     pointer  to  indicate  a  NULL string.  A NULL pointer is an
     error and results in an abort of the program.  If  you  wish
     to  indicate  a  NULL  string,  you must have a pointer that
     points to an explicit NULL string.  On some  implementations
     of  the  C  language  on  some  machines, a NULL pointer, if
     dereferenced, would yield a NULL string;  this  highly  non-
     portable trick was used in some programs.  Programmers using
     a NULL pointer to represent an empty string should be  aware
     of  this  portability  issue;  even  on machines where dere-
     ferencing a NULL pointer does not cause an abort of the pro-
     gram,  it does not necessarily yield a NULL string.  Charac-
     ter movement is performed differently in different implemen-
     tations.  Thus overlapping moves may yield surprises.
















             Last change: BSD Compatibility Package             1