Tcl_SetErrno(3)

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

SYNOPSIS
       #include <<tcl.h>>

       void
       Tcl_SetErrno(errorCode)

       int
       Tcl_GetErrno()

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.

KEYWORDS
       errno, error code, global variables