Brought in my temporary printf to cleanup the shell

bin/shell/SConscript

@@ -13,7 +13,7 @@ src_common = [
 src.append(src_common)
 
 init_env.Append(LINKFLAGS = ['-nostdlib'])
-init_env.Append(CPPFLAGS = ['-nostdinc'])
+init_env.Append(CPPFLAGS = ['-fno-builtin', '-nostdinc'])
 init_env.Append(CPPPATH = ['#build/include'])
 init_env.Append(LIBPATH = ['#build/lib/libc'], LIBS = ['c'])
 

bin/shell/shell.c

@@ -17,7 +17,7 @@ main(int argc, const char *argv[])
 {
     char buf[256];
 
-    fputs("System Shell\n", stdout);
+    printf("System Shell\n");
     while (1) {
 	fputs("Shell> ", stdout);
 	fgets(buf, sizeof(buf), stdin);
@@ -29,10 +29,10 @@ main(int argc, const char *argv[])
 void
 Cmd_Help(int argc, const char *argv[])
 {
-    fputs("cat        Print file\n", stdout);
+    printf("cat        Print file\n");
-    fputs("echo       Echo arguments\n", stdout);
+    printf("echo       Echo arguments\n");
-    fputs("exit       Exit shell\n", stdout);
+    printf("exit       Exit shell\n");
-    fputs("help       Display the list of commands\n", stdout);
+    printf("help       Display the list of commands\n");
 }
 
 void
@@ -42,10 +42,9 @@ Cmd_Echo(int argc, const char *argv[])
 
     for (i = 1; i < argc; i++)
     {
-        fputs(argv[i], stdout);
+	printf("%s ", argv[i]);
-        fputs(" ", stdout);
     }
-    fputs("\n", stdout);
+    printf("\n");
 }
 
 void
@@ -78,8 +77,7 @@ Cmd_List(int argc, const char *argv[])
 	    break;
 	}
 
-	fputs(de.d_name, stdout);
+	printf("%s\n", de.d_name);
-	fputs("\n", stdout);
     }
 }
 
@@ -158,7 +156,7 @@ DispatchCommand(char *buf)
     } else if (strcmp(argv[0], "#") == 0) {
 	// Ignore comments
     } else if (buf[0] != '\0') {
-        fputs("Unknown command\n", stdout);
+        printf("Unknown command '%s'\n", buf);
     }
 }
 

include/stdio.h

@@ -34,5 +34,8 @@ int fputs(const char *str, FILE *fh);
 int fgetc(FILE *fh);
 char *fgets(char *str, int size, FILE *fh);
 
+int printf(const char *fmt, ...);
+int fprintf(FILE *stream, const char *fmt, ...);
+
 #endif /* __STDIO_H__ */
 

lib/libc/SConscript

@@ -12,6 +12,7 @@ src_common = [
     "file.c",
     "string.c",
     "syscall.c",
+    "printf.c",
     "posix/mman.c",
 ]
 

lib/libc/printf.c

@@ -0,0 +1,236 @@
+/*
+ * Copyright (c) 2013-2014 Stanford University
+ * Copyright (c) 2006-2008 Ali Mashtizadeh
+ * All rights reserved.
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+
+// static unsigned long getuint(va_list *ap, int lflag)
+#define getuint(ap, lflag) \
+    (lflag == 8) ? va_arg(ap, uint64_t) : \
+    (lflag == 4) ? va_arg(ap, uint32_t) : \
+    (lflag == 2) ? va_arg(ap, uint32_t) : \
+    (lflag == 1) ? va_arg(ap, uint32_t) : 0
+
+// static long getint(va_list *ap, int lflag)
+#define getint(ap, lflag) \
+    (lflag == 8) ? va_arg(ap, int64_t) : \
+    (lflag == 4) ? va_arg(ap, int32_t) : \
+    (lflag == 2) ? va_arg(ap, int32_t) : \
+    (lflag == 1) ? va_arg(ap, int32_t) : 0
+
+static const char *numberstring_lower = "0123456789abcdef";
+static const char *numberstring_upper = "0123456789ABCDEF";
+
+static void printnum(void (*func)(int, void*),void *handle,
+                     uint64_t num,int base,int width,int padc)
+{
+    char buf[64];
+    char *p = buf;
+    int spaces;
+    if (base < 0)
+    {
+        base = -base;
+        do {
+            *p = numberstring_upper[num % base];
+            p++;
+        } while (num /= base);
+    } else {
+        do {
+            *p = numberstring_lower[num % base];
+            p++;
+        } while (num /= base);
+    }
+
+    // Print spacers (pre-number)
+    spaces = width - (p - buf);
+    if (padc == ' ' || padc == '0') {
+	while (spaces > 0)
+	{
+	    func(padc, handle);
+	    spaces--;
+	}
+    }
+
+    // Print Number
+    while (p != buf) {
+        p--;
+        func((int)*p, handle);
+    }
+
+    // Print spacers (post-number)
+    if (padc == '-') {
+	while (spaces > 0)
+	{
+	    func(' ', handle);
+	    spaces--;
+	}
+    }
+}
+
+static int kvprintf(char const *fmt, void (*func)(int,void *), void *handle, va_list ap)
+{
+    const char *p;
+    int ch;
+    uint64_t unum;
+    int64_t num;
+    int lflag, width, padc;
+
+    while (1) {
+        while ((ch = *(unsigned char *)fmt++) != '%') {
+            if (ch == '\0') return -1;
+            func(ch, handle);
+        }
+
+        width = -1;
+        lflag = 4;
+        padc = ' ';
+again:
+        switch (ch = *(unsigned char *)fmt++) {
+            case '-':
+                padc = '-';
+                goto again;
+            case '0':
+                padc = '0';
+                goto again;
+            case '1':
+            case '2':
+            case '3':
+            case '4':
+            case '5':
+            case '6':
+            case '7':
+            case '8':
+            case '9':
+                width = 0;
+                while (1) {
+                    width = 10 * width + ch - '0';
+                    ch = *fmt;
+                    if (ch < '0' || ch > '9')
+                    {
+                        break;
+                    }
+                    fmt++;
+                    if (ch == '\0')
+                    {
+                        fmt--;
+                        goto again;
+                    }
+                }
+                goto again;
+            case 'c':
+                func(va_arg(ap, int) & 0xff, handle);
+                break;
+            case 's': {
+		int spaces;
+
+		p = va_arg(ap, char *);
+		if (p == NULL) {
+		    func('*', handle);
+		    func('N', handle);
+		    func('U', handle);
+		    func('L', handle);
+		    func('L', handle);
+		    func('*', handle);
+		    break;
+		}
+		spaces = width - strlen(p);
+
+		if (padc == ' ') {
+		    while (spaces > 0)
+		    {
+			func(' ', handle);
+			spaces--;
+		    }
+		}
+
+		while (*p != '\0')
+		{
+		    func(*p++, handle);
+		}
+
+		if (padc == '-') {
+		    while (spaces > 0)
+		    {
+			func(' ', handle);
+			spaces--;
+		    }
+		}
+		break;
+            }
+            case 'd':
+                num = getint(ap, lflag);
+                if (num < 0) {
+                    func('-', handle);
+                    unum = -num;
+                } else {
+                    unum = num;
+                }
+                printnum(func, handle, unum, 10, width, padc);
+                break;
+            case 'u':
+                unum = getuint(ap, lflag);
+                printnum(func, handle, unum, 10, width, padc);
+                break;
+            case 'o':
+                unum = getuint(ap, lflag);
+                printnum(func, handle, unum, 8, width, padc);
+                break;
+            case 'p':
+                unum = (unsigned long)va_arg(ap, void *);
+                printnum(func, handle, unum, 8, width, padc);
+                break;
+            case 'x':
+                unum = getuint(ap, lflag);
+                printnum(func, handle, unum, 16, width, padc);
+                break;
+            case 'X':
+                unum = getuint(ap, lflag);
+                printnum(func, handle, unum, -16, width, padc);
+                break;
+            case 'l':
+                lflag = 8;
+                goto again;
+            case '%':
+            default: // Print Literally
+                func(ch, handle);
+                break;
+        }
+    }
+    return 0;
+}
+
+static void fileputc(int c, void* handle)
+{
+    fputc(c, (FILE *)handle);
+}
+
+int printf(const char *fmt, ...)
+{
+    int ret;
+    va_list ap;
+
+    va_start(ap, fmt);
+    ret = kvprintf(fmt, fileputc, (void *)stdout, ap);
+    va_end(ap);
+
+    return ret;
+}
+
+int fprintf(FILE *stream, const char *fmt, ...)
+{
+    int ret;
+    va_list ap;
+
+    va_start(ap, fmt);
+    ret = kvprintf(fmt, fileputc, stream, ap);
+    va_end(ap);
+
+    return ret;
+}
+