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-rw-r--r--libguile/init.c81
1 files changed, 59 insertions, 22 deletions
diff --git a/libguile/init.c b/libguile/init.c
index f170bd1f0..2cda6eb64 100644
--- a/libguile/init.c
+++ b/libguile/init.c
@@ -248,32 +248,69 @@ check_config (void)
/* initializing standard and current I/O ports */
-/* Like scm_fdes_to_port, except that:
- - NAME is a standard C string, not a Guile string
- - we set the revealed count for FILE's file descriptor to 1, so
- that FDES won't be closed when the port object is GC'd.
- - when FDES is not a valid file descripter (as determined by
- fstat), we open "/dev/null" and use that instead. In that case,
- the revealed count is left at zero.
-*/
+typedef struct
+{
+ int fdes;
+ char *mode;
+ char *name;
+} stream_body_data;
+
+/* proc to be called in scope of exception handler stream_handler. */
static SCM
-scm_standard_stream_to_port (int fdes, char *mode, char *name)
+stream_body (void *data)
{
- struct stat st;
- if (fstat (fdes, &st) == -1)
- {
- /* We do not bother to check errno. When fstat fails, there is
- generally no point in trying to use FDES, I think. */
+ stream_body_data *body_data = (stream_body_data *) data;
+ SCM port = scm_fdes_to_port (body_data->fdes, body_data->mode,
+ scm_makfrom0str (body_data->name));
- fdes = open ("/dev/null", (mode[0] == 'r')? O_RDONLY : O_WRONLY);
- return scm_fdes_to_port (fdes, mode, scm_makfrom0str (name));
- }
- else
+ SCM_REVEALED (port) = 1;
+ return port;
+}
+
+/* exception handler for stream_body. */
+static SCM
+stream_handler (void *data, SCM tag, SCM throw_args)
+{
+ return SCM_BOOL_F;
+}
+
+/* Convert a file descriptor to a port, using scm_fdes_to_port.
+ - NAME is a C string, not a Guile string
+ - set the revealed count for FILE's file descriptor to 1, so
+ that fdes won't be closed when the port object is GC'd.
+ - catch exceptions: allow Guile to be able to start up even
+ if it has been handed bogus stdin/stdout/stderr. In this case
+ try to open a new stream on /dev/null. */
+static SCM
+scm_standard_stream_to_port (int fdes, char *mode, char *name)
+{
+ SCM port;
+ stream_body_data body_data;
+
+ body_data.fdes = fdes;
+ body_data.mode = mode;
+ body_data.name = name;
+ port = scm_internal_catch (SCM_BOOL_T, stream_body, &body_data,
+ stream_handler, NULL);
+ if (SCM_FALSEP (port))
{
- SCM port = scm_fdes_to_port (fdes, mode, scm_makfrom0str (name));
- scm_set_port_revealed_x (port, SCM_MAKINUM (1));
- return port;
- }
+ /* FIXME: /dev/null portability. there's also *null-device* in
+ r4rs.scm. */
+ int null_fdes = open ("/dev/null",
+ (mode[0] == 'r') ? O_RDONLY : O_WRONLY);
+
+ body_data.fdes = null_fdes;
+ port = (null_fdes == -1) ? SCM_BOOL_F
+ : scm_internal_catch (SCM_BOOL_T, stream_body, &body_data,
+ stream_handler, NULL);
+ /* if the standard fdes was not allocated, reset the revealed count
+ on the grounds that the user doesn't know what it is. */
+ if (SCM_NFALSEP (port) && null_fdes != fdes)
+ SCM_REVEALED (port) = 0;
+ /* if port is still #f, we'll just leave it like that and
+ an error will be raised on the first attempt to use it. */
+ }
+ return port;
}
/* Create standard ports from stdin, stdout, and stderr. */