Tcl_SetErrno(3)       Tcl Library Procedures      Tcl_SetErrno(3)



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NAME
       Tcl_SetErrno,  Tcl_GetErrno,  Tcl_ErrnoId,  Tcl_ErrnoMsg -
       manipulate errno to store and retrieve error codes

SYNOPSIS
       #include 

       void
       Tcl_SetErrno(errorCode)

       int
       Tcl_GetErrno()

       CONST char *
       Tcl_ErrnoId()

       CONST char *
       Tcl_ErrnoMsg(errorCode)


ARGUMENTS
       int   errorCode   (in)      A POSIX  error  code  such  as
                                   ENOENT.
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DESCRIPTION
       Tcl_SetErrno  and  Tcl_GetErrno provide portable access to
       the errno variable, which is used to record a POSIX  error
       code  after  system  calls  and  other  operations such as
       Tcl_Gets.  These procedures are necessary  because  global
       variable  accesses cannot be made across module boundaries
       on some platforms.

       Tcl_SetErrno sets the errno variable to the value  of  the
       errorCode  argument C procedures that wish to return error
       information  to  their  callers  via  errno  should   call
       Tcl_SetErrno rather than setting errno directly.

       Tcl_GetErrno  returns  the current value of errno.  Proce-
       dures wishing to access errno should call  this  procedure
       instead of accessing errno directly.

       Tcl_ErrnoId and Tcl_ErrnoMsg return string representations
       of errno values.  Tcl_ErrnoId returns  a  machine-readable
       textual  identifier  such  as "EACCES" that corresponds to
       the current value of errno.  Tcl_ErrnoMsg returns a human-
       readable  string  such  as "permission denied" that corre-
       sponds to the value of its errorCode argument.  The error-
       Code   argument   is   typically  the  value  returned  by
       Tcl_GetErrno.  The strings returned by these functions are
       statically  allocated and the caller must not free or mod-
       ify them.


KEYWORDS
       errno, error code, global variables



Tcl                            8.3                Tcl_SetErrno(3)