diff --git a/include/ke/sched.h b/include/ke/sched.h
index f63f1f0..1c9f7f0 100644
--- a/include/ke/sched.h
+++ b/include/ke/sched.h
@@ -61,8 +61,8 @@ extern const char *PsPrioClassesNames[];
 // Re-scheduling and preemption
 // XXX atomic operations
 //
-#define PsRequestReSched()     (++KeCurCPU->needReSched)
-#define PsDisablePreemption()  (++KeCurCPU->preemptCount)
+#define PsRequestReSched()     do { ++KeCurCPU->needReSched; } while (0)
+#define PsDisablePreemption()  do { ++KeCurCPU->preemptCount; } while (0)
 #define PsEnablePreemption()   do { assert(KeCurCPU->preemptCount > 0); \
                                     --KeCurCPU->preemptCount; } while(0)
 
diff --git a/include/lib/buf.h b/include/lib/buf.h
index 58808a9..f5b6630 100644
--- a/include/lib/buf.h
+++ b/include/lib/buf.h
@@ -138,14 +138,18 @@ int         BGetState(Buffer_t *);
 error_t     BFlushBuf(Buffer_t *);
 
 error_t     BPutOnBuf(Buffer_t *, uchar);
-error_t     BWriteOnBuf(Buffer_t *, uchar *, size_t);
-error_t     BPrintOnBuf(Buffer_t *, const char *, ...);
-error_t     BPrintOnBufV(Buffer_t *, const char *, va_list);
-
 error_t     BGetFromBuf(Buffer_t *, uchar *);
-error_t     BReadBuf(Buffer_t *, uchar *, size_t);
-error_t     BScanBuf(Buffer_t *, const char *, ...);
-error_t     BScanBufV(Buffer_t *, const char *, va_list);
+
+// The following functions return the number of bytes written to the buffer
+size_t      BWriteOnBuf(Buffer_t *, uchar *, size_t);
+size_t      BPrintOnBuf(Buffer_t *, const char *, ...);
+size_t      BPrintOnBufV(Buffer_t *, const char *, va_list);
+
+// The following functions return the number of elements from their	
+// va_list's their wrote too, e.g. successful bscanf("%d %d", &a, &b) == 2	
+size_t      BReadFromBuf(Buffer_t *, uchar *, size_t);
+size_t      BScanFromBuf(Buffer_t *, const char *, ...);
+size_t      BScanFromBufV(Buffer_t *, const char *, va_list);
 
 void        BLockBuf(Buffer_t *);
 void        BUnlockBuf(Buffer_t *);
@@ -157,14 +161,14 @@ bool        BTrylockBuf(Buffer_t *);
 //
 
 error_t     bputc(Buffer_t *, uchar);
-error_t     bwrite(Buffer_t *, uchar *, size_t);
-error_t     bprintf(Buffer_t *, const char *, ...);
-error_t     vbprintf(Buffer_t *, const char *, va_list);
+size_t      bwrite(Buffer_t *, uchar *, size_t);
+size_t      bprintf(Buffer_t *, const char *, ...);
+size_t      vbprintf(Buffer_t *, const char *, va_list);
 
 error_t     bgetc(Buffer_t *, uchar *);
-error_t     bread(Buffer_t *, uchar *, size_t);
-error_t     bscanf(Buffer_t *, const char *, ...);
-error_t     vbscanf(Buffer_t *, const char *, va_list);
+size_t      bread(Buffer_t *, uchar *, size_t);
+size_t      bscanf(Buffer_t *, size_t *, const char *, ...);
+size_t      vbscanf(Buffer_t *, size_t *, const char *, va_list);
 
 error_t     bemptybuf(Buffer_t *);
 error_t     bscrolldown(Buffer_t *);
diff --git a/kaleid/kernel/ke/panic.c b/kaleid/kernel/ke/panic.c
index 63773fa..0a46373 100644
--- a/kaleid/kernel/ke/panic.c
+++ b/kaleid/kernel/ke/panic.c
@@ -26,7 +26,6 @@
 #include <ke/proc.h>
 #include <io/vga.h>
 
-error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap);
 extern bool KeIdtIsInitialized;
 
 //
diff --git a/kaleid/libbuf/bgetc.c b/kaleid/libbuf/bgetc.c
index 9aa4726..f4a8bd1 100644
--- a/kaleid/libbuf/bgetc.c
+++ b/kaleid/libbuf/bgetc.c
@@ -43,6 +43,9 @@ error_t BGetFromBuf(Buffer_t *buf, uchar *ch)
     ExReleaseLock(&buf->lock);
     return rc;
 }
+
+// Note: any change to this must be done while
+// keeping in mind vbscanf()'s workaround for ungetc()
 error_t bgetc(Buffer_t *buf, uchar *ch)
 {
     error_t rc = EOK;
@@ -70,6 +73,9 @@ error_t bgetc(Buffer_t *buf, uchar *ch)
         while (buf->rp >= buf->wp) {
 #ifdef _KALEID_KERNEL
             KeSleep(1);     // XXX synchronization with keyboard driver
+#else
+            buf->flags |= BF_EOF;
+            return EENDF;   // Currently empty
 #endif
         }
         
diff --git a/kaleid/libbuf/bprint.c b/kaleid/libbuf/bprint.c
index 56faeb9..b455b16 100644
--- a/kaleid/libbuf/bprint.c
+++ b/kaleid/libbuf/bprint.c
@@ -31,73 +31,41 @@
 //
 // Prints formatted string on buf according to fmt
 //
-error_t BPrintOnBuf(Buffer_t *buf, const char *fmt, ...)
+size_t BPrintOnBuf(Buffer_t *buf, const char *fmt, ...)
 {
-    error_t rc;
+    size_t sz;
     va_list ap;
 
     va_start(ap, fmt);
     ExAcquireLock(&buf->lock);
-    rc = vbprintf(buf, fmt, ap);
+    sz = vbprintf(buf, fmt, ap);
     ExReleaseLock(&buf->lock);
     va_end(ap);
 
-    return rc;
+    return sz;
 }
 
-error_t BPrintOnBufV(Buffer_t *buf, const char *fmt, va_list ap)
+size_t BPrintOnBufV(Buffer_t *buf, const char *fmt, va_list ap)
 {
-    error_t rc;
+    size_t sz;
     
     ExAcquireLock(&buf->lock);
-    rc = vbprintf(buf, fmt, ap);
+    sz = vbprintf(buf, fmt, ap);
     ExReleaseLock(&buf->lock);
     
-    return rc;
+    return sz;
 }
 
-error_t bprintf(Buffer_t *buf, const char *fmt, ...)
+size_t bprintf(Buffer_t *buf, const char *fmt, ...)
 {
-    error_t rc;
+    error_t sz;
     va_list ap;
 
     va_start(ap, fmt);
-    rc = vbprintf(buf, fmt, ap);
+    sz = vbprintf(buf, fmt, ap);
     va_end(ap);
 
-    return rc;
-}
-
-//
-// Prints 0 for octal, 0x for hexadecimal, 0b for binary
-//
-static error_t bprinthash(Buffer_t *buf, int base, int cap)
-{
-    error_t rc;
-
-    if (base != 2 && base != 8 && base != 16) {
-        return EOK;
-    }
-
-    rc = bputc(buf, '0');
-
-    if (!rc && base != 8) {
-        rc = bputc(buf, (base == 2 ? 'b' : (cap ? 'X' : 'x')));
-    }
-
-    return rc;
-}
-
-static error_t bdopadding(Buffer_t *buf, size_t width, size_t len,
-                          char filler)
-{
-    error_t rc = EOK;
-
-    for (; !rc && width > len ; width--) {
-        rc = bputc(buf, filler);
-    }
-
-    return rc;
+    return sz;
 }
 
 #define CONVBUFSIZE 100
@@ -106,9 +74,10 @@ static error_t bdopadding(Buffer_t *buf, size_t width, size_t len,
 // Actually does BPrintOnBuf's job; doesn't lock anything
 // Quite a long function
 //
-error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
+size_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
 {
     error_t rc = 0;
+    size_t written = 0;
 
     ssize_t width, prec, len;
     char type;
@@ -134,10 +103,11 @@ error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
     // Base
     int base;
 
-    if (!buf || !fmt) return EINVAL;
-    if (buf->flags & (BF_EOF|BF_ERR)) return EENDF;
+    if (!buf || !fmt) { seterrno(EINVAL); return 0; }
+    if (buf->flags & (BF_EOF|BF_ERR)) { seterrno(EENDF); return 0; }
     if (buf->state != BS_RDWR && buf->state != BS_WRONLY) {
-        return EBADF;
+        seterrno(EBADF);
+        return 0;
     }
 
     // Progress in format string
@@ -146,14 +116,12 @@ error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
         // Deal with all non-'%' characters
         if (*fmt != '%') {
             rc = bputc(buf, *fmt);
-            
-            fmt++;
+            written++, fmt++;
             continue;
         }
 
         //
-        // %[parameter][flags][width|*][.precision|*][length]type
-        // We aren't dealing with parameters and floating stuff just yet
+        // %[flags][width|*][.precision|*][length]type
         //
 
         // Skip the '%'
@@ -162,8 +130,7 @@ error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
         // "%%" modifier
         if (*fmt == '%') {
             rc = bputc(buf, '%');
-            
-            fmt++;
+            written++, fmt++;
             continue;
         }
 
@@ -253,6 +220,7 @@ error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
         if (type == 'c') {
             uch = (uchar)va_arg(ap, int);
             rc = bputc(buf, uch);
+            written++;
 
             continue;
         }
@@ -261,11 +229,11 @@ error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
         if (type == 'C') {
             base = va_arg(ap, int);
             
-            if (!(base < 0 || base > VGA_COLOR_WHITE))
+            if (!(base < 0 || base > VGA_COLOR_WHITE)) {
                 rc = bputc(buf, RtlColorToChar(base));
-            
-            
-            assert(!rc && 1);
+                written++;
+            }
+
             continue;
         }
 #endif
@@ -281,8 +249,9 @@ error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
             // Zero/nonspecified precision means unlimited amount
             if (prec == 0) prec = INT_MAX;
             
-            for (; *s && prec-- ; s++) {
+            for (; !rc && *s && prec-- ; s++) {
                 rc = bputc(buf, (uchar)*s);
+                written++;
             }
 
             continue;
@@ -292,6 +261,7 @@ error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
         // Make sure width and prec aren't too big
         // (We didn't do that earlier because %s uses width) 
         if (width > CONVBUFSIZE || prec > CONVBUFSIZE) {
+            written++; // Work around "if (rc) return written - 1;"
             rc = EINVAL;
             break;
         }
@@ -314,15 +284,15 @@ error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
         // End of string too soon
         else if (type == '\0') {
             bputc(buf, '%');
+            written++; // Work around "if (rc) return written - 1;"
             rc = EINVAL;
             break;
         }
 
         // Unknown/unsupported modifier
         else {
-            bputc(buf, '%');
-            bputc(buf, '?');
-            rc = bputc(buf, type);
+            rc = bputc(buf, '%');
+            written++;
             continue;
         }
 
@@ -382,36 +352,62 @@ error_t vbprintf(Buffer_t *buf, const char *fmt, va_list ap)
         }
 
         // When padding with spaces, we pad before +/-'s etc
-        if (!minus && !zero && width > len)
-            bdopadding(buf, width, len, ' ');
+        if (!minus && !zero && width > len) {
+            for (; !rc && width > len ; width--) {
+                rc = bputc(buf, ' ');
+                written++;
+            }
+        }
 
         // Deal with signs and the hash flag
-        if (*s == '-') { rc = bputc(buf, '-'); s++, len--; }
-        else if (sgn && plus) rc = bputc(buf, '+');
-        else if (sgn && space) rc = bputc(buf, ' ');
-        else if (hash) bprinthash(buf, base, cap);
+        if (*s == '-') { rc = bputc(buf, '-'); s++, len--; written++; }
+        else if (sgn && plus) { rc = bputc(buf, '+'); written++; }
+        else if (sgn && space) { rc = bputc(buf, ' '); written++; }
+
+        // Print 0 for octal, 0x for hexadecimal, 0b for binary
+        else if (hash && (base == 2 || base == 8 || base == 16)) { 
+            rc = bputc(buf, '0');
+            written++;
+
+            if (!rc && base != 8) {
+                rc = bputc(buf, (base == 2 ? 'b' : (cap ? 'X' : 'x')));
+                written++;
+            }
+        }
 
         // Deal with padding by zeroes
         // The 'minus' flag makes no sense with the 'zero' one
-        if (zero && width > len)
-            bdopadding(buf, width, len, '0');
+        if (zero && width > len) {
+            for (; !rc && width > len ; width--) {
+                rc = bputc(buf, '0');
+                written++;
+            }
+        }
 
         // Output the actual number
         for (; !rc && *s ; s++) {
             rc = bputc(buf, (uchar)*s);
+            written++;
         }
 
         // 'minus' padding, only with spaces
-        if (minus && !zero && width > len)
-            bdopadding(buf, width, base, ' ');
+        if (minus && !zero && width > len) {
+            for (; !rc && width > len ; width--) {
+                rc = bputc(buf, ' ');
+                written++;
+            }
+        }
             
         // Carry on to next modifier
-   }
-   
-   // For debugging purposes
-   if(rc)KeStartPanic("%s",strerror(rc));
-   assert(!rc && "vbprintf() error");
+    }
 
-   return rc;
+    // For debugging purposes
+    assert(!rc && "vbprintf() error");
+    seterrno(rc);
+
+    if (rc)
+        return written - 1;     // "- 1" because last bputc() must have failed
+    else
+        return written;
 }
 
diff --git a/kaleid/libbuf/bscan.c b/kaleid/libbuf/bscan.c
index f85037f..5b5a260 100644
--- a/kaleid/libbuf/bscan.c
+++ b/kaleid/libbuf/bscan.c
@@ -22,5 +22,190 @@
 //  along with OS/K.  If not, see <https://www.gnu.org/licenses/>.            //
 //----------------------------------------------------------------------------//
 
+#if 0
 #include <lib/buf.h>
 
+//
+// Builds string reading from buf according to fmt
+//
+size_t BScanFromBuf(Buffer_t *buf, const char *fmt, ...)
+{
+    size_t sz;
+    va_list ap;
+
+    va_start(ap, fmt);
+    ExAcquireLock(&buf->lock);
+    sz = vbscanf(buf, fmt, ap);
+    ExReleaseLock(&buf->lock);
+    va_end(ap);
+
+    return sz;
+}
+
+size_t BScanFromBufV(Buffer_t *buf, const char *fmt, va_list ap)
+{
+    size_t rc;
+    
+    ExAcquireLock(&buf->lock);
+    sz = vbscanf(buf, fmt, ap);
+    ExReleaseLock(&buf->lock);
+    
+    return sz;
+}
+
+size_t bscanf(Buffer_t *buf, const char *fmt, ...)
+{
+    size_t sz;
+    va_list ap;
+
+    va_start(ap, fmt);
+    sz = vbscanf(buf, fmt, ap);
+    va_end(ap);
+
+    return sz;
+}
+
+size_t vbscanf(Buffer_t *buf, const char *fmt, va_list ap)
+{
+    error_t rc = EOK;
+
+    size_t readcnt = 0;
+    uchar ch = 0;
+
+    bool l, h;
+
+    size_t width;
+    bool ignore;    // '*' modifier, don't write to va_list for current mod
+
+    if (!buf || !fmt) { seterrnp(EINVAL); return 0; }
+    if (buf->flags & (BF_EOF|BF_ERR)) { seterrno(EENDF); return 0; }
+    if (buf->state != BS_RDWR && buf->state != BS_WRONLY) {
+        seterrno(EBADF);
+        return 0;
+    }
+
+    // Progress in format string
+    for (*fmt && !rc) {
+        
+        // Skip all kinds of whitespaces
+        if (isspace(*fmt)) {
+
+        another_space:
+            rc = bgetc(buf, &ch);
+
+            if (!rc) break;
+
+            // Put back non-whitespaces and progress
+            if (!isspace(ch)) {
+                buf->rp--;
+                do { fmt++; } while (isspace(*fmt));
+                continue;
+            }
+
+            else goto another_space;
+        }
+    
+        // Deal with all non-'%' non-whitespace characters
+        if (*fmt != '%') {
+            rc = bgetc(buf, &ch);
+
+            // Is it what we expected?
+            if (!rc && ch != *fmt) {
+                // No, so put it back
+                buf->rp--;
+                break;
+            }
+
+            // We don't do anything with these characters
+            continue;
+        }
+
+        //
+        // %[*][width][modifier]type
+        //
+
+        // Skip the %
+        fmt++;
+
+        // '%%' type
+        if (*fmt == '%') {
+            rc = bgetc(buf, &ch);
+
+            if (!rc && ch != '%') {
+                buf->rp--;
+                break;
+            }
+            
+            continue;
+        }
+
+        l = h = 0;
+        width = 0;
+        ignore = 0;
+
+        // Don't write to variable
+        if (*fmt == '*') {
+            ignore = 1;
+            fmt++;
+        }
+
+        // Extract width field
+        while (isdigit(*fmt)) {
+            width = 10 * width + (*fmt - '0');
+            fmt++;
+        }
+
+        assert(!(width < 0)); 
+
+        //
+        // Extract length field
+        //
+
+        if (*fmt == 'l') {
+            l = 1;
+            fmt++;
+        }
+
+        else if (*fmt == 'h') {
+            h = 1;
+            fmt++
+        }
+
+        //
+        // Types
+        //
+
+        // Read character(s)
+        if (*fmt == 'c') {
+            if (width == 0) width = 1;
+
+            // For >1 width, read that many characters
+            // then store them in successive argument pointers 
+            for (; width; width--) {
+                rc = bgetc(buf, &ch);
+                if (!rc) break;
+
+                char *chptr = va_arg(ap, char *);
+                 *chptr = (char)ch;
+                 readcnt++;
+            }
+        }
+
+        // Decimal integer
+        else if (*fmt == 'd') {
+            
+        }
+    }
+
+    // For debugging purposes
+    assert(!rc && "vbscanf() error");
+    seterrno(rc);
+
+    return readcnt;
+}
+
+
+
+#endif
+
+
diff --git a/kaleid/libc/sprintf.c b/kaleid/libc/sprintf.c
index ab5a98f..3aaf031 100644
--- a/kaleid/libc/sprintf.c
+++ b/kaleid/libc/sprintf.c
@@ -35,14 +35,14 @@
 // Once libbuf is supports dynamic buffers, the only changes necessary
 // will be to change the value below to and add a line to vsnprintf()
 //
-#define VSNPRINTF_MAX 512
+#define VSNPRINTF_MAX 4096
 
 //
 // Format str according to fmt using ellipsed arguments
 //
 size_t sprintf(char *str, const char *fmt, ...)
 {
-    int ret;
+    size_t ret;
     va_list ap;
 
     assert(!"sprintf() is deprecated, used snprintf() for more safety");
@@ -65,7 +65,7 @@ size_t vsprintf(char *str, const char *fmt, va_list ap)
 //
 size_t snprintf(char *str, size_t n, const char *fmt, ...)
 {
-    int ret;
+    size_t ret;
     va_list ap;
 
     va_start(ap, fmt);
@@ -77,8 +77,8 @@ size_t snprintf(char *str, size_t n, const char *fmt, ...)
 
 size_t vsnprintf(char *str, size_t n, const char *fmt, va_list ap)
 {
-    size_t ret;
-    error_t rc = EOK;
+    error_t rc;
+    size_t ret, sz;
     Buffer_t *buf = NULL;
 
     assert(str && fmt);
@@ -96,33 +96,23 @@ size_t vsnprintf(char *str, size_t n, const char *fmt, va_list ap)
         goto fail;
     }
 
-    rc = vbprintf(buf, fmt, ap);
+    sz = vbprintf(buf, fmt, ap);
 
     // We don't mind EOFs, just just return how much was successfully written
-    if (rc != EOK) {
-        if (rc == EENDF) {
-            if (!(buf->flags & BF_EOF)) {
-                goto fail;
-            }
-        }
-        else {
+    if (sz == 0 && !(buf->flags & BF_EOF))
             goto fail;
-        }
-    }
     
     ret = (size_t)buf->wp - (size_t)buf->buf;
     
-    if (ret > 0) {
-        // To be changed to memcpy()
+    if (ret > 0)
         memmove(str, (char *)buf->buf, ret);
-    }
 
     str[ret++] = 0;
     assert(ret <= n);
 
     BCloseBuf(buf);
     return ret;
-    
+
 fail:
     KeStartPanic("vsnprintf() failure\nRC: %d\nbuf->flags & BF_EOF: %d\n",
                  rc, buf->flags & BF_EOF);