Diff: printf-stdarg.c

Revision:

10:716484b1ddb5

diff -r 10fcf3d0ec2d -r 716484b1ddb5 printf-stdarg.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/printf-stdarg.c	Tue Apr 05 18:30:41 2016 +0000
@@ -0,0 +1,266 @@
+/*
+	Copyright 2001, 2002 Georges Menie (www.menie.org)
+	stdarg version contributed by Christian Ettinger
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+/*
+	putchar is the only external dependency for this file,
+	if you have a working putchar, leave it commented out.
+	If not, uncomment the define below and
+	replace outbyte(c) by your own function call. */
+
+#define putchar(c) putcharNB(c)
+
+
+#include <stdarg.h>
+
+static void printchar(char **str, int c)
+{
+	extern int putchar(int c);
+	
+	if (str) {
+		**str = c;
+		++(*str);
+	}
+	else (void)putchar(c);
+}
+
+#define PAD_RIGHT 1
+#define PAD_ZERO 2
+
+static int prints(char **out, const char *string, int width, int pad)
+{
+	register int pc = 0, padchar = ' ';
+
+	if (width > 0) {
+		register int len = 0;
+		register const char *ptr;
+		for (ptr = string; *ptr; ++ptr) ++len;
+		if (len >= width) width = 0;
+		else width -= len;
+		if (pad & PAD_ZERO) padchar = '0';
+	}
+	if (!(pad & PAD_RIGHT)) {
+		for ( ; width > 0; --width) {
+			printchar (out, padchar);
+			++pc;
+		}
+	}
+	for ( ; *string ; ++string) {
+		printchar (out, *string);
+		++pc;
+	}
+	for ( ; width > 0; --width) {
+		printchar (out, padchar);
+		++pc;
+	}
+
+	return pc;
+}
+
+/* the following should be enough for 32 bit int */
+#define PRINT_BUF_LEN 12
+
+static int printi(char **out, int i, int b, int sg, int width, int pad, int letbase)
+{
+	char print_buf[PRINT_BUF_LEN];
+	register char *s;
+	register int t, neg = 0, pc = 0;
+	register unsigned int u = i;
+
+	if (i == 0) {
+		print_buf[0] = '0';
+		print_buf[1] = '\0';
+		return prints (out, print_buf, width, pad);
+	}
+
+	if (sg && b == 10 && i < 0) {
+		neg = 1;
+		u = -i;
+	}
+
+	s = print_buf + PRINT_BUF_LEN-1;
+	*s = '\0';
+
+	while (u) {
+		t = u % b;
+		if( t >= 10 )
+			t += letbase - '0' - 10;
+		*--s = t + '0';
+		u /= b;
+	}
+
+	if (neg) {
+		if( width && (pad & PAD_ZERO) ) {
+			printchar (out, '-');
+			++pc;
+			--width;
+		}
+		else {
+			*--s = '-';
+		}
+	}
+
+	return pc + prints (out, s, width, pad);
+}
+
+static int print(char **out, const char *format, va_list args )
+{
+	register int width, pad;
+	register int pc = 0;
+	char scr[2];
+
+	for (; *format != 0; ++format) {
+		if (*format == '%') {
+			++format;
+			width = pad = 0;
+			if (*format == '\0') break;
+			if (*format == '%') goto out;
+			if (*format == '-') {
+				++format;
+				pad = PAD_RIGHT;
+			}
+			while (*format == '0') {
+				++format;
+				pad |= PAD_ZERO;
+			}
+			for ( ; *format >= '0' && *format <= '9'; ++format) {
+				width *= 10;
+				width += *format - '0';
+			}
+			if( *format == 's' ) {
+				register char *s = (char *)va_arg( args, int );
+				pc += prints (out, s?s:"(null)", width, pad);
+				continue;
+			}
+			if( *format == 'd' ) {
+				pc += printi (out, va_arg( args, int ), 10, 1, width, pad, 'a');
+				continue;
+			}
+			if( *format == 'x' ) {
+				pc += printi (out, va_arg( args, int ), 16, 0, width, pad, 'a');
+				continue;
+			}
+			if( *format == 'X' ) {
+				pc += printi (out, va_arg( args, int ), 16, 0, width, pad, 'A');
+				continue;
+			}
+			if( *format == 'u' ) {
+				pc += printi (out, va_arg( args, int ), 10, 0, width, pad, 'a');
+				continue;
+			}
+			if( *format == 'c' ) {
+				/* char are converted to int then pushed on the stack */
+				scr[0] = (char)va_arg( args, int );
+				scr[1] = '\0';
+				pc += prints (out, scr, width, pad);
+				continue;
+			}
+		}
+		else {
+		out:
+			printchar (out, *format);
+			++pc;
+		}
+	}
+	if (out) **out = '\0';
+	va_end( args );
+	return pc;
+}
+
+int printfNB(const char *format, ...)
+{
+        va_list args;
+        
+        va_start( args, format );
+        return print( 0, format, args );
+}
+
+int sprintf(char *out, const char *format, ...)
+{
+        va_list args;
+        
+        va_start( args, format );
+        return print( &out, format, args );
+}
+
+#ifdef TEST_PRINTF
+int main(void)
+{
+	char *ptr = "Hello world!";
+	char *np = 0;
+	int i = 5;
+	unsigned int bs = sizeof(int)*8;
+	int mi;
+	char buf[80];
+
+	mi = (1 << (bs-1)) + 1;
+	printf("%s\n", ptr);
+	printf("printf test\n");
+	printf("%s is null pointer\n", np);
+	printf("%d = 5\n", i);
+	printf("%d = - max int\n", mi);
+	printf("char %c = 'a'\n", 'a');
+	printf("hex %x = ff\n", 0xff);
+	printf("hex %02x = 00\n", 0);
+	printf("signed %d = unsigned %u = hex %x\n", -3, -3, -3);
+	printf("%d %s(s)%", 0, "message");
+	printf("\n");
+	printf("%d %s(s) with %%\n", 0, "message");
+	sprintf(buf, "justif: \"%-10s\"\n", "left"); printf("%s", buf);
+	sprintf(buf, "justif: \"%10s\"\n", "right"); printf("%s", buf);
+	sprintf(buf, " 3: %04d zero padded\n", 3); printf("%s", buf);
+	sprintf(buf, " 3: %-4d left justif.\n", 3); printf("%s", buf);
+	sprintf(buf, " 3: %4d right justif.\n", 3); printf("%s", buf);
+	sprintf(buf, "-3: %04d zero padded\n", -3); printf("%s", buf);
+	sprintf(buf, "-3: %-4d left justif.\n", -3); printf("%s", buf);
+	sprintf(buf, "-3: %4d right justif.\n", -3); printf("%s", buf);
+
+	return 0;
+}
+
+/*
+ * if you compile this file with
+ *   gcc -Wall $(YOUR_C_OPTIONS) -DTEST_PRINTF -c printf.c
+ * you will get a normal warning:
+ *   printf.c:214: warning: spurious trailing `%' in format
+ * this line is testing an invalid % at the end of the format string.
+ *
+ * this should display (on 32bit int machine) :
+ *
+ * Hello world!
+ * printf test
+ * (null) is null pointer
+ * 5 = 5
+ * -2147483647 = - max int
+ * char a = 'a'
+ * hex ff = ff
+ * hex 00 = 00
+ * signed -3 = unsigned 4294967293 = hex fffffffd
+ * 0 message(s)
+ * 0 message(s) with %
+ * justif: "left      "
+ * justif: "     right"
+ *  3: 0003 zero padded
+ *  3: 3    left justif.
+ *  3:    3 right justif.
+ * -3: -003 zero padded
+ * -3: -3   left justif.
+ * -3:   -3 right justif.
+ */
+
+#endif