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.

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 a string representation of the current errno value. Tcl_ErrnoId returns a machine-readable textual identifier 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 
Copyright © 1996 Sun Microsystems, Inc.
Copyright © 1995-1997 Roger E. Critchlow Jr.