'\" '\" Copyright (c) 1996 Sun Microsystems, Inc. '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" '\" RCS: @(#) SetErrno.3,v 1.5 2003/01/21 19:39:59 hunt Exp .so man.macros .TH Tcl_SetErrno 3 8.3 Tcl "Tcl Library Procedures" .BS .SH NAME Tcl_SetErrno, Tcl_GetErrno, Tcl_ErrnoId, Tcl_ErrnoMsg \- manipulate errno to store and retrieve error codes .SH SYNOPSIS .nf \fB#include <tcl.h>\fR .sp void \fBTcl_SetErrno\fR(\fIerrorCode\fR) .sp int \fBTcl_GetErrno\fR() .sp CONST char * \fBTcl_ErrnoId\fR() .sp CONST char * \fBTcl_ErrnoMsg\fR(\fIerrorCode\fR) .sp .SH ARGUMENTS .AS int errorCode in .AP int errorCode in A POSIX error code such as \fBENOENT\fR. .BE .SH DESCRIPTION .PP \fBTcl_SetErrno\fR and \fBTcl_GetErrno\fR provide portable access to the \fBerrno\fR variable, which is used to record a POSIX error code after system calls and other operations such as \fBTcl_Gets\fR. These procedures are necessary because global variable accesses cannot be made across module boundaries on some platforms. .PP \fBTcl_SetErrno\fR sets the \fBerrno\fR variable to the value of the \fIerrorCode\fR argument C procedures that wish to return error information to their callers via \fBerrno\fR should call \fBTcl_SetErrno\fR rather than setting \fBerrno\fR directly. .PP \fBTcl_GetErrno\fR returns the current value of \fBerrno\fR. Procedures wishing to access \fBerrno\fR should call this procedure instead of accessing \fBerrno\fR directly. .PP \fBTcl_ErrnoId\fR and \fBTcl_ErrnoMsg\fR return string representations of \fBerrno\fR values. \fBTcl_ErrnoId\fR returns a machine-readable textual identifier such as "EACCES" that corresponds to the current value of \fBerrno\fR. \fBTcl_ErrnoMsg\fR returns a human-readable string such as "permission denied" that corresponds to the value of its \fIerrorCode\fR argument. The \fIerrorCode\fR argument is typically the value returned by \fBTcl_GetErrno\fR. The strings returned by these functions are statically allocated and the caller must not free or modify them. .SH KEYWORDS errno, error code, global variables