tcl7.6 C API - GetOpnFl
NAME
Tcl_GetOpenFile - Get a standard IO File * handle from a
channel.
SYNOPSIS
#include <tcl.h>
int
Tcl_GetOpenFile(interp, string, write, checkUsage, filePtr)
ARGUMENTS
Tcl_Interp *interp (in) Tcl interpreter from
which file handle is to
be obtained.
char *string (in) String identifying chan-
nel, such as stdin or
file4.
int write (in) Non-zero means the file
will be used for writ-
ing, zero means it will
be used for reading.
int checkUsage (in) If non-zero, then an
error will be generated
if the file wasn't
opened for the access
indicated by write.
ClientData *filePtr (out) Points to word in which
to store pointer to FILE
structure for the file
given by string.
DESCRIPTION
Tcl_GetOpenFile takes as argument a file identifier of the
form returned by the open command and returns at *filePtr a
pointer to the FILE structure for the file. The write argu-
ment indicates whether the FILE pointer will be used for
reading or writing. In some cases, such as a channel that
connects to a pipeline of subprocesses, different FILE
pointers will be returned for reading and writing.
Tcl_GetOpenFile normally returns TCL_OK. If an error occurs
in Tcl_GetOpenFile (e.g. string didn't make any sense or
checkUsage was set and the file wasn't opened for the access
specified by write) then TCL_ERROR is returned and interp-
>result will contain an error message. In the current
implementation checkUsage is ignored and consistency checks
are always performed.
KEYWORDS
channel, file handle, permissions, pipeline, read, write