From: solar <unknown>
Date: Mon, 14 Sep 2009 05:25:57 +0000 (+0000)
Subject: First work towards scanf().
X-Git-Tag: v0.5~124
X-Git-Url: https://pd.if.org/git/?p=pdclib;a=commitdiff_plain;h=68525aefa7b7b1f2f769e287e1f2f3a4585005ff

First work towards scanf().
---

diff --git a/Makefile b/Makefile
index 7750bf2..e9ba02e 100644
--- a/Makefile
+++ b/Makefile
@@ -13,7 +13,7 @@ SRCFILES := $(shell find $(PROJDIRS) -mindepth 1 -maxdepth 3 -name "*.c")
 # All header files of the project
 HDRFILES := $(shell find $(PROJDIRS) -mindepth 1 -maxdepth 3 -name "*.h")
 # All .c files in functions/_PDCLIB that do not have a regression test driver
-INTFILES := _Exit atomax digits open print remove rename seed stdinit strtox_main strtox_prelim cleanstream fflush filemode eol errno seek prepread prepwrite
+INTFILES := _Exit atomax digits open print scan remove rename seed stdinit strtox_main strtox_prelim cleanstream fflush filemode eol errno seek prepread prepwrite
 # All object files in the library
 OBJFILES := $(patsubst %.c,%.o,$(SRCFILES))
 # All test drivers (.t)
diff --git a/functions/_PDCLIB/scan.c b/functions/_PDCLIB/scan.c
new file mode 100644
index 0000000..d12e884
--- /dev/null
+++ b/functions/_PDCLIB/scan.c
@@ -0,0 +1,25 @@
+/* $Id$ */
+
+/* _PDCLIB_scan( const char *, struct _PDCLIB_status_t * )
+
+   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>
+
+const char * _PDCLIB_scan( const char * spec, struct _PDCLIB_status_t * status )
+{
+    return ++spec;
+}
+
+#ifdef TEST
+#include <_PDCLIB_test.h>
+
+int main( void )
+{
+    TESTCASE( NO_TESTDRIVER );
+    return TEST_RESULTS;
+}
+
+#endif
diff --git a/functions/stdio/vsscanf.c b/functions/stdio/vsscanf.c
index 75f334d..c4565aa 100644
--- 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;
 }
 
diff --git a/internals/_PDCLIB_int.h b/internals/_PDCLIB_int.h
index 02e122e..62c38b2 100644
--- a/internals/_PDCLIB_int.h
+++ b/internals/_PDCLIB_int.h
@@ -345,12 +345,21 @@ extern char _PDCLIB_Xdigits[];
 /* The worker for all printf() type of functions. The pointer spec should point
    to the introducing '%' of a conversion specifier. The status structure is to
    be that of the current printf() function, of which the members n, s, stream
-   and arg will be preserved, i will be updated, and all others will be trashed
+   and arg will be preserved; i will be updated; and all others will be trashed
    by the function.
    Returns a pointer to the first character not parsed as conversion specifier.
 */
 const char * _PDCLIB_print( const char * spec, struct _PDCLIB_status_t * status );
 
+/* The worker for all scanf() type of functions. The pointer spec should point
+   to the introducing '%' of a conversion specifier. The status structure is to
+   be that of the current scanf() function, of which the member stream will be
+   preserved, n, i, and s will be updated; and all others will be trashed by the
+   function.
+   Returns a pointer to the first character not parsed as conversion specifier.
+*/
+const char * _PDCLIB_scan( const char * spec, struct _PDCLIB_status_t * status );
+
 /* Parsing any fopen() style filemode string into a number of flags. */
 unsigned int _PDCLIB_filemode( const char * mode );