Tcl_SetErrno(3)

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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.
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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 bound-
       aries 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)