NAME

       Tcl_SetErrno,  Tcl_GetErrno,  Tcl_ErrnoId,  Tcl_ErrnoMsg  -  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)

ARGUMENTS

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

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.  Procedures 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 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.

KEYWORDS

       errno, error code, global variables