man.postnix Miscellaneous man pages of Plan 9 related material

     ISALPHARUNE(2)                                     ISALPHARUNE(2)

     NAME
          isalpharune, islowerrune, isspacerune, istitlerune,
          isupperrune, isdigitrune, tolowerrune, totitlerune,
          toupperrune - Unicode character classes and cases

     SYNOPSIS
          #include <u.h>
          #include <libc.h>

          int isalpharune(Rune c)

          int islowerrune(Rune c)

          int isspacerune(Rune c)

          int istitlerune(Rune c)

          int isupperrune(Rune c)

          int isdigitrune(Rune c)

          Rune tolowerrune(Rune c)

          Rune totitlerune(Rune c)

          Rune toupperrune(Rune c)

     DESCRIPTION
          These routines examine and operate on Unicode characters, in
          particular a subset of their properties as defined in the
          Unicode standard.  Unicode defines some characters as alpha-
          betic and specifies three cases: upper, lower, and title.
          Analogously to ctype(2) for ASCII, these routines test types
          and modify cases for Unicode characters.  The names are
          self-explanatory.

          The case-conversion routines return the character unchanged
          if it has no case.

          If a rune contains a value that is not a valid codepoint
          (ie, greater than Runemax), these routines return 0.

     SOURCE
          /sys/src/libc/port/mkrunetype.c
          /sys/src/libc/port/runeistype.c
          /sys/src/libc/port/runetotype.c

     SEE ALSO
          ctype(2), The Unicode Standard.

     Page 1                       Plan 9            (printed 10/29/25)