SetErrno

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 <tcl.h>

       void
       Tcl_SetErrno(errorCode)

       int
       Tcl_GetErrno()

       char *
       Tcl_ErrnoId()

       char *
       Tcl_ErrnoMsg()


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  bound-
       aries 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 a string representation of the cur-
       rent errno value.  Tcl_ErrnoId returns a machine-readable textual iden-
       tifier such as "EACCES". Tcl_ErrnoMsg returns a  human-readable  string
       such  as  "permission denied".  The strings returned by these functions
       are statically allocated and the caller must not free or modify them.


KEYWORDS
       errno, error code, global variables



Tcl                                   8.3                      Tcl_SetErrno(3)