conv

Purpose

     Translates characters.

Library

     Standard C Library (libc.a)

Syntax

     #include <ctype.h>

     int toupper (c)                           int NCtoupper (x)
     int c;                                    int x;

     int tolower (c)                           int NCtolower (x)
     int c;                                    int x;

     int _toupper (c)                          int _NCtoupper (x)
     int c;                                    int x;

     int _tolower (c)                          int _NCtolower (x)
     int c;                                    int x;

     int toascii (c)                           int NCtoNLchar (x)
     int c;                                    int x;

     int NCesc (xp, cp)                        int NCunesc (cp, xp)
     NLchar *xp;                               char *cp;
     char *cp;                                 NLchar *xp;

                                               int NCflatchr (x)
                                               int x;
     Description

     The  NCxxxxxxx  subroutines   translate  all  characters,
     including extended characters, as code points (see "Over-
     view of International Character  Support" in Managing the
     AIX Operating  System).  The other  subroutines translate
     traditional ASCII characters only.

     The toupper  and the  tolower subroutines have  as domain
     the range of the getc subroutine:  from -1 through 255.

     If the  parameter of the toupper  subroutine represents a
     lowercase letter, the result  is the corresponding upper-
     case letter.  If the  parameter of the tolower subroutine
     represents an uppercase letter,  the result is the corre-
     sponding  lowercase  letter.   All other  values  in  the
     domain are returned unchanged.

     The _toupper and _tolower routines are macros that accom-
     plish the  same thing  as toupper  and tolower,  but they

     have restricted  domains and  they are  faster.  _toupper
     requires a lowercase letter  as its parameter; its result
     is the corresponding uppercase letter.  _tolower requires
     an uppercase letter  as its parameter; its  result is the
     corresponding  lowercase  letter.    Values  outside  the
     domain cause undefined results.

     The value of x is in the  domain of any legal NLchar in a
     value range from  0 to NLCHARMAX inclusive,  or a special
     value of -1 (which represents EOF).

     If the parameter of the NCtoupper subroutine represents a
     lowercase  letter  according  to  the  current  collating
     sequence configuration,  the result is  the corresponding
     uppercase letter.  If the parameter of the NLtolower sub-
     routine represents  an uppercase letter according  to the
     current collating  sequence configuration, the  result is
     the corresponding  lowercase letter. All other  values in
     the domain are returned unchanged.

     The _NCtoupper  and _NCtolower  routines are  macros that
     accomplish the same thing as NCtoupper and NCtolower, but
     have  restricted  domains  and  are  faster.   _NCtoupper
     requires a lowercase letter  as its parameter; its result
     is  the   corresponding  uppercase   letter.   _NCtolower
     requires an uppercase letter as its parameter; its result
     is  the corresponding  lowercase letter.   Values outside
     the domain cause undefined results.

     The toascii subroutine yields  the value of its parameter
     with all bits that are not part of a standard ASCII char-
     acter turned off.  It  is intended for compatibility with
     other systems.

     The NCtoNLchar subroutine yields  the value of its param-
     eter with  all bits turned  off that  are not part  of an
     NLchar.

     The NCesc macro converts the  NLchar value xp into one or
     more ASCII bytes stored in the character array pointed to
     by cp.   If the NLchar represents  an extended character,
     it is  converted into  a printable ASCII  escape sequence
     that uniquely  identifies the extended  character.  NCesc
     returns  the  number of  bytes  it  wrote.  See  "display
     symbols" for  a list that  shows the escape  sequence for
     each character.

     The inverse conversion is performed by the NCunesc macro,
     translating  an ordinary  ASCII byte  or escape  sequence
     starting  at cp  into  a single  NLchar  at xp.   NCunesc
     returns the number of bytes it read.

     The  NCflatchr subroutine  converts  its parameter  value
     into the  single ASCII  byte that most  closely resembles
     the  parameter  character  in appearance.   If  no  ASCII
     equivalent exists,  it converts the parameter  value to a
     "?" (question mark).

     Related Information

     In this  book:  "ctype,"   "getc, fgetc,  getchar, getw,"
     and  "display symbols."

     "Overview of International Character Support" in Managing
     the AIX Operating System.