--- /dev/null
+#include "vilibc.h"
+
+enum {
+ OUT_BUF
+};
+
+static int intern_printf(int out, char *buf, unsigned long sz, const char *fmt, va_list ap);
+static void bwrite(int out, char *buf, unsigned long buf_sz, char *str, int sz);
+
+int sprintf(char *buf, const char *fmt, ...)
+{
+ int res;
+ va_list ap;
+
+ va_start(ap, fmt);
+ res = intern_printf(OUT_BUF, buf, 0, fmt, ap);
+ va_end(ap);
+ return res;
+}
+
+int vsprintf(char *buf, const char *fmt, va_list ap)
+{
+ return intern_printf(OUT_BUF, buf, 0, fmt, ap);
+}
+
+int snprintf(char *buf, unsigned long sz, const char *fmt, ...)
+{
+ int res;
+ va_list ap;
+
+ va_start(ap, fmt);
+ res = intern_printf(OUT_BUF, buf, sz, fmt, ap);
+ va_end(ap);
+ return res;
+}
+
+int vsnprintf(char *buf, unsigned long sz, const char *fmt, va_list ap)
+{
+ return intern_printf(OUT_BUF, buf, sz, fmt, ap);
+}
+
+/* intern_printf provides all the functionality needed by all the printf
+ * variants.
+ * - buf: optional buffer onto which the formatted results are written. If null
+ * then the output goes to the terminal through putchar calls. This is used
+ * by the (v)sprintf variants which write to an array of char.
+ * - sz: optional maximum size of the output, 0 means unlimited. This is used
+ * by the (v)snprintf variants to avoid buffer overflows.
+ * The rest are obvious, format string and variable argument list.
+ */
+static char *convc = "dioxXucsfeEgGpn%";
+
+#define IS_CONV(c) strchr(convc, c)
+
+#define BUF(x) ((x) ? (x) + cnum : (x))
+#define SZ(x) ((x) ? (x) - cnum : (x))
+
+static int intern_printf(int out, char *buf, unsigned long sz, const char *fmt, va_list ap)
+{
+ char conv_buf[32];
+ char *str;
+ int i, slen;
+ const char *fstart = 0;
+
+ /* state */
+ int cnum = 0;
+ int base = 10;
+ int alt = 0;
+ int fwidth = 0;
+ int padc = ' ';
+ int sign = 0;
+ int left_align = 0;
+ int hex_caps = 0;
+ int unsig = 0;
+ int num, unum;
+
+ while(*fmt) {
+ if(*fmt == '%') {
+ fstart = fmt++;
+ continue;
+ }
+
+ if(fstart) {
+ if(IS_CONV(*fmt)) {
+ switch(*fmt) {
+ case 'X':
+ hex_caps = 1;
+
+ case 'x':
+ case 'p':
+ base = 16;
+
+ if(alt) {
+ bwrite(out, BUF(buf), SZ(sz), "0x", 2);
+ cnum += 2;
+ }
+
+ case 'u':
+ unsig = 1;
+
+ if(0) {
+ case 'o':
+ base = 8;
+
+ if(alt) {
+ bwrite(out, BUF(buf), SZ(sz), "0", 1);
+ cnum++;
+ }
+ }
+
+ case 'd':
+ case 'i':
+ if(unsig) {
+ unum = va_arg(ap, unsigned int);
+ utoa(unum, conv_buf, base);
+ } else {
+ num = va_arg(ap, int);
+ itoa(num, conv_buf, base);
+ }
+ if(hex_caps) {
+ for(i=0; conv_buf[i]; i++) {
+ conv_buf[i] = toupper(conv_buf[i]);
+ }
+ }
+
+ slen = strlen(conv_buf);
+
+ if(left_align) {
+ if(!unsig && sign && num >= 0) {
+ bwrite(out, BUF(buf), SZ(sz), "+", 1);
+ cnum++;
+ }
+ bwrite(out, BUF(buf), SZ(sz), conv_buf, slen);
+ cnum += slen;
+ padc = ' ';
+ }
+ for(i=slen; i<fwidth; i++) {
+ bwrite(out, BUF(buf), SZ(sz), (char*)&padc, 1);
+ cnum++;
+ }
+ if(!left_align) {
+ if(!unsig && sign && num >= 0) {
+ bwrite(out, BUF(buf), SZ(sz), "+", 1);
+ cnum++;
+ }
+ bwrite(out, BUF(buf), SZ(sz), conv_buf, slen);
+ cnum += slen;
+ }
+ break;
+
+ case 'c':
+ {
+ char c = va_arg(ap, int);
+ bwrite(out, BUF(buf), SZ(sz), &c, 1);
+ cnum++;
+ }
+ break;
+
+ case 's':
+ str = va_arg(ap, char*);
+ slen = strlen(str);
+
+ if(left_align) {
+ bwrite(out, BUF(buf), SZ(sz), str, slen);
+ cnum += slen;
+ padc = ' ';
+ }
+ for(i=slen; i<fwidth; i++) {
+ bwrite(out, BUF(buf), SZ(sz), (char*)&padc, 1);
+ cnum++;
+ }
+ if(!left_align) {
+ bwrite(out, BUF(buf), SZ(sz), str, slen);
+ cnum += slen;
+ }
+ break;
+
+ case 'n':
+ *va_arg(ap, int*) = cnum;
+ break;
+
+ default:
+ break;
+ }
+
+ /* restore default conversion state */
+ base = 10;
+ alt = 0;
+ fwidth = 0;
+ padc = ' ';
+ hex_caps = 0;
+
+ fstart = 0;
+ fmt++;
+ } else {
+ switch(*fmt) {
+ case '#':
+ alt = 1;
+ break;
+
+ case '+':
+ sign = 1;
+ break;
+
+ case '-':
+ left_align = 1;
+ break;
+
+ case 'l':
+ case 'L':
+ break;
+
+ case '0':
+ padc = '0';
+ break;
+
+ default:
+ if(isdigit(*fmt)) {
+ const char *fw = fmt;
+ while(*fmt && isdigit(*fmt)) fmt++;
+
+ fwidth = atoi(fw);
+ continue;
+ }
+ }
+ fmt++;
+ }
+ } else {
+ bwrite(out, BUF(buf), SZ(sz), (char*)fmt++, 1);
+ cnum++;
+ }
+ }
+
+ return cnum;
+}
+
+/* bwrite is called by intern_printf to transparently handle writing into a
+ * buffer or to the terminal
+ */
+static void bwrite(int out, char *buf, unsigned long buf_sz, char *str, int sz)
+{
+ int i;
+
+ if(out == OUT_BUF) {
+ if(buf_sz && buf_sz <= sz) sz = buf_sz;
+ buf[sz] = 0;
+ memcpy(buf, str, sz);
+ }
+}
projects / visor / blobdiff