X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=functions%2Fstdio%2Ffopen.c;h=f11094416066ed91a9f6bb6d358b4dcebea981c9;hb=5a313c5a48d18419e78d03a04501d7fe21f49d3f;hp=04020d94645a1f52dee6f3bd88da52c0e91f4850;hpb=dcc8a8e99f69e090a03b7b868443addbc0817820;p=pdclib.old

diff --git a/functions/stdio/fopen.c b/functions/stdio/fopen.c
index 04020d9..f110944 100644
--- a/functions/stdio/fopen.c
+++ b/functions/stdio/fopen.c
@@ -1,8 +1,103 @@
-// ----------------------------------------------------------------------------
-// $Id$
-// ----------------------------------------------------------------------------
-// Public Domain C Library - http://pdclib.sourceforge.net
-// This code is Public Domain. Use, modify, and redistribute at will.
-// ----------------------------------------------------------------------------
-
-FILE * fopen( const char * restrict filename, const char * restrict mode ) { /* TODO */ };
+/* $Id$ */
+
+/* fopen( const char *, const char * )
+
+   This file is part of the Public Domain C Library (PDCLib).
+   Permission is granted to use, modify, and / or redistribute at will.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef REGTEST
+#include <_PDCLIB_glue.h>
+
+static FILE * _PDCLIB_filelist = NULL;
+
+/* Helper function that parses the C-style mode string passed to fopen() into
+   the PDCLib flags.FREAD, FWRITE, FAPPEND, FRW (read-write) and FBIN (
+   mode).
+*/
+static unsigned int filemode( char const * const mode )
+{
+    int rc = 0;
+    switch ( mode[0] )
+    {
+        case 'r':
+            rc |= _PDCLIB_FREAD;
+            break;
+        case 'w':
+            rc |= _PDCLIB_FWRITE;
+            break;
+        case 'a':
+            rc |= _PDCLIB_FAPPEND;
+            break;
+        default:
+            /* Other than read, write, or append - invalid */
+            return 0;
+    }
+    for ( size_t i = 1; i < 4; ++i )
+    {
+        switch ( mode[1] )
+        {
+            case '+':
+                if ( rc & _PDCLIB_FRW ) return 0; /* Duplicates are invalid */
+                rc |= _PDCLIB_FRW;
+                break;
+            case 'b':
+                if ( rc & _PDCLIB_FBIN ) return 0; /* Duplicates are invalid */
+                rc |= _PDCLIB_FBIN;
+                break;
+            case '\0':
+                /* End of mode */
+                return rc;
+            default:
+                /* Other than read/write or binary - invalid. */
+                return 0;
+        }
+    }
+    /* Longer than three chars - invalid. */
+    return 0;
+}
+
+FILE * fopen( const char * _PDCLIB_restrict filename, const char * _PDCLIB_restrict mode )
+{
+    FILE * rc;
+    if ( mode == NULL || filename == NULL || filename[0] == '\0' )
+    {
+        /* Mode or filename invalid */
+        return NULL;
+    }
+    if ( ( rc = calloc( 1, sizeof( FILE ) ) ) == NULL )
+    {
+        /* no memory for another FILE */
+        return NULL;
+    }
+    if ( ( rc->status = filemode( mode ) ) == 0 ) goto fail; /* invalid mode */
+    rc->handle = _PDCLIB_open( filename, rc->status );
+    if ( rc->handle == _PDCLIB_NOHANDLE ) goto fail; /* OS open() failed */
+
+    /* Adding to list of open files */
+    rc->next = _PDCLIB_filelist;
+    _PDCLIB_filelist = rc;
+    /* Setting buffer. TODO: Check for unbuffered? */
+    if ( ( rc->buffer = malloc( BUFSIZ ) ) == NULL goto fail;
+    /* TODO: Setting mbstate */
+    return rc;
+fail:
+    free( rc );
+    return NULL;
+}
+
+#endif
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    TESTCASE( NO_TESTDRIVER );
+    return TEST_RESULTS;
+}
+
+#endif