Tcl_SetErrno manual page - Tcl Library Procedures

Tcl8.6.7/Tk8.6.7 Documentation > Tcl C API, version 8.6.7 > SetErrno

Tcl/Tk Applications | Tcl Commands | Tk Commands | [incr Tcl] Package Commands | SQLite3 Package Commands | TDBC Package Commands | tdbc::mysql Package Commands | tdbc::odbc Package Commands | tdbc::postgres Package Commands | tdbc::sqlite3 Package Commands | Thread Package Commands | Tcl C API | Tk C API | [incr Tcl] Package C API | TDBC Package C API

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
DESCRIPTION
KEYWORDS

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
Copyright © 1996 Sun Microsystems, Inc.