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Tcl_SetErrno(3) 	     Tcl Library Procedures		 Tcl_SetErrno(3)

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

SYNOPSIS
     #include <tcl.h>

     void
     Tcl_SetErrno(errorCode)

     int
     Tcl_GetErrno()

     const char *
     Tcl_ErrnoId()

     const char *
     Tcl_ErrnoMsg(errorCode)

     void
     Tcl_WinConvertError(winErrorCode)

ARGUMENTS
     int errorCode (in) 	 A POSIX error code such as ENOENT.

     DWORD winErrorCode (in)		 A Windows or Winsock error code such as
					 ERROR_FILE_NOT_FOUND.
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DESCRIPTION
     Tcl_SetErrno and Tcl_GetErrno provide portable access to  the  errno  vari-
     able,  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 er-
     rno should call Tcl_SetErrno rather than setting errno directly.

     Tcl_GetErrno returns the current value of errno.  Procedures wishing to ac-
     cess 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 hu-
     man-readable  string  such  as  "permission denied" that corresponds to the
     value of its errorCode argument.  The errorCode 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 modify them.

     Tcl_WinConvertError (Windows only) maps the passed Windows or Winsock error
     code to a POSIX error and stores it in errno.

KEYWORDS
     errno, error code, global variables

Tcl				       8.3			 Tcl_SetErrno(3)
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