Change the mapping of file descriptors to FILE *klibc-0.96

3 files changed, 21 insertions, 13 deletions

diff --git a/include/stdio.h b/include/stdio.h
index f57439f018a58..31a1fe40af296 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -31,15 +31,22 @@ typedef struct _IO_file FILE;
 #define SEEK_CUR 1
 #define SEEK_END 2
 
+/*
+ * Convert between a FILE * and a file descriptor.  We don't actually
+ * have any in-memory data, so we just abuse the pointer itself to
+ * hold the data.  Note, however, that for file descriptors, -1 is
+ * error and 0 is a valid value; for FILE *, NULL (0) is error and
+ * non-NULL are valid.
+ */
 static __inline__ int fileno(FILE *__f)
 {
   /* This should really be intptr_t, but size_t should be the same size */
-  return (int)(size_t)__f;
+  return (int)(size_t)__f - 1;
 }
 
 static __inline__ FILE * __create_file(int __fd)
 {
-  return (FILE *)(size_t)__fd;
+  return (FILE *)(size_t)(__fd + 1);
 }
 
 __extern FILE *fopen(const char *, const char *);
diff --git a/klibc/fopen.c b/klibc/fopen.c
index 5c84184809af4..ee62c68bd7520 100644
--- a/klibc/fopen.c
+++ b/klibc/fopen.c
@@ -13,10 +13,9 @@ FILE *fopen(const char *file, const char *mode)
 {
   int flags = O_RDONLY;
   int plus = 0;
-  int fd;
 
   while ( *mode ) {
-    switch ( *mode ) {
+    switch ( *mode++ ) {
     case 'r':
       flags = O_RDONLY;
       break;
@@ -30,17 +29,12 @@ FILE *fopen(const char *file, const char *mode)
       plus = 1;
       break;
     }
-    mode++;
   }
 
   if ( plus ) {
     flags = (flags & ~(O_RDONLY|O_WRONLY)) | O_RDWR;
   }
 
-  fd = open(file, flags, 0666);
-
-  if ( fd < 0 )
-    return NULL;
-  else
-    return fdopen(fd, mode);
+  /* Note: __create_file(-1) == NULL, so this is safe */
+  return __create_file(open(file, flags, 0666));
 }
diff --git a/klibc/include/stdio.h b/klibc/include/stdio.h
index f57439f018a58..31a1fe40af296 100644
--- a/klibc/include/stdio.h
+++ b/klibc/include/stdio.h
@@ -31,15 +31,22 @@ typedef struct _IO_file FILE;
 #define SEEK_CUR 1
 #define SEEK_END 2
 
+/*
+ * Convert between a FILE * and a file descriptor.  We don't actually
+ * have any in-memory data, so we just abuse the pointer itself to
+ * hold the data.  Note, however, that for file descriptors, -1 is
+ * error and 0 is a valid value; for FILE *, NULL (0) is error and
+ * non-NULL are valid.
+ */
 static __inline__ int fileno(FILE *__f)
 {
   /* This should really be intptr_t, but size_t should be the same size */
-  return (int)(size_t)__f;
+  return (int)(size_t)__f - 1;
 }
 
 static __inline__ FILE * __create_file(int __fd)
 {
-  return (FILE *)(size_t)__fd;
+  return (FILE *)(size_t)(__fd + 1);
 }
 
 __extern FILE *fopen(const char *, const char *);