Tcl_SetErrno(3) Tcl Library Procedures Tcl_SetErrno(3)

____________________________________________________________________________

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

Tcl 8.3 Tcl_SetErrno(3)