DragonFly On-Line Manual Pages

Search: Section:  

Tcl_SetErrno(3)             Tcl Library Procedures             Tcl_SetErrno(3)



Tcl_SetErrno, Tcl_GetErrno, Tcl_ErrnoId, Tcl_ErrnoMsg - manipulate errno to store and retrieve error codes


#include <tcl.h> void Tcl_SetErrno(errorCode) int Tcl_GetErrno() const char * Tcl_ErrnoId() const char * Tcl_ErrnoMsg(errorCode)


int errorCode (in) A POSIX error code such as ENOENT. ______________________________________________________________________________


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.


errno, error code, global variables Tcl 8.3 Tcl_SetErrno(3)

Search: Section: