First work towards scanf().

[pdclib] / functions / stdio / vsscanf.c

diff --git a/functions/stdio/vsscanf.c b/functions/stdio/vsscanf.c
index 75f334d11b403b45935d81361c8baf0aa434ca00..c4565aada0320a307c06a044991c4acd504ce450 100644 (file)
--- a/functions/stdio/vsscanf.c
+++ b/functions/stdio/vsscanf.c
@@ -13,8 +13,64 @@
 
 int vsscanf( const char * _PDCLIB_restrict s, const char * _PDCLIB_restrict format, va_list arg )
 {
-    /* TODO: Implement. */
-    return 0;
+    struct _PDCLIB_status_t status;
+    status.base = 0;
+    status.flags = 0;
+    /* In _PDCLIB_print, status.n holds the maximum number of characters to be
+       written. As we don't need that for the scanf() functions, we (ab)use
+       this field to hold the number of matching conversion specifiers.
+    */
+    status.n = 0; 
+    status.i = 0;
+    status.this = 0;
+    /* In _PDCLIB_print, status.s is the string *printed to*. In the scanf()
+       functions, we (ab)use this field to hold the string *scanned from*.
+    */
+    status.s = (char *)s;
+    status.width = 0;
+    status.prec = 0;
+    status.stream = NULL;
+    va_copy( status.arg, arg );
+    while ( *format != '\0' )
+    {
+        const char * rc;
+        if ( ( *format != '%' ) || ( ( rc = _PDCLIB_scan( format, &status ) ) == format ) )
+        {
+            /* No conversion specifier, match verbatim */
+            if ( isspace( *format ) )
+            {
+                /* Whitespace char in format string: Skip all whitespaces */
+                /* No whitespaces in input do not result in matching error */
+                while ( isspace( *status.s ) )
+                {
+                    ++status.s;
+                    ++status.i;
+                }
+            }
+            else
+            {
+                /* Non-whitespace char in format string: Match verbatim */
+                if ( *status.s != *format )
+                {
+                    /* Matching error */
+                    return status.n;
+                }
+                else
+                {
+                    ++status.s;
+                    ++status.i;
+                }
+            }
+            ++format;
+        }
+        else
+        {
+            /* Continue parsing after conversion specifier */
+            format = rc;
+        }
+    }
+    va_end( status.arg );
+    return status.n;
 }
 
 #endif
@@ -24,7 +80,18 @@ int vsscanf( const char * _PDCLIB_restrict s, const char * _PDCLIB_restrict form
 
 int main( void )
 {
-    TESTCASE( NO_TESTDRIVER );
+    char const * teststring1 = "abc  def";
+    char const * teststring2 = "abcdef";
+    char const * teststring3 = "abc%def";
+    int x;
+    TESTCASE( sscanf( teststring2, "abcdef%n", &x ) == 0 );
+    TESTCASE( x == 6 );
+    TESTCASE( sscanf( teststring1, "abc def%n", &x ) == 0 );
+    TESTCASE( x == 8 );
+    TESTCASE( sscanf( teststring2, "abc def%n", &x ) == 0 );
+    TESTCASE( x == 6 );
+    TESTCASE( sscanf( teststring3, "abc%%def%n", &x ) == 0 );
+    TESTCASE( x == 7 );
     return TEST_RESULTS;
 }