7 static int intern_printf(int out, char *buf, unsigned long sz, const char *fmt, va_list ap);
8 static void bwrite(int out, char *buf, unsigned long buf_sz, char *str, int sz);
10 int sprintf(char *buf, const char *fmt, ...)
16 res = intern_printf(OUT_BUF, buf, 0, fmt, ap);
21 int vsprintf(char *buf, const char *fmt, va_list ap)
23 return intern_printf(OUT_BUF, buf, 0, fmt, ap);
26 int snprintf(char *buf, unsigned long sz, const char *fmt, ...)
32 res = intern_printf(OUT_BUF, buf, sz, fmt, ap);
37 int vsnprintf(char *buf, unsigned long sz, const char *fmt, va_list ap)
39 return intern_printf(OUT_BUF, buf, sz, fmt, ap);
42 /* intern_printf provides all the functionality needed by all the printf
44 * - buf: optional buffer onto which the formatted results are written. If null
45 * then the output goes to the terminal through putchar calls. This is used
46 * by the (v)sprintf variants which write to an array of char.
47 * - sz: optional maximum size of the output, 0 means unlimited. This is used
48 * by the (v)snprintf variants to avoid buffer overflows.
49 * The rest are obvious, format string and variable argument list.
51 static char *convc = "dioxXucsfeEgGpn%";
53 #define IS_CONV(c) strchr(convc, c)
55 #define BUF(x) ((x) ? (x) + cnum : (x))
56 #define SZ(x) ((x) ? (x) - cnum : (x))
58 static int intern_printf(int out, char *buf, unsigned long sz, const char *fmt, va_list ap)
63 const char *fstart = 0;
94 bwrite(out, BUF(buf), SZ(sz), "0x", 2);
106 bwrite(out, BUF(buf), SZ(sz), "0", 1);
114 unum = va_arg(ap, unsigned int);
115 utoa(unum, conv_buf, base);
117 num = va_arg(ap, int);
118 itoa(num, conv_buf, base);
121 for(i=0; conv_buf[i]; i++) {
122 conv_buf[i] = toupper(conv_buf[i]);
126 slen = strlen(conv_buf);
129 if(!unsig && sign && num >= 0) {
130 bwrite(out, BUF(buf), SZ(sz), "+", 1);
133 bwrite(out, BUF(buf), SZ(sz), conv_buf, slen);
137 for(i=slen; i<fwidth; i++) {
138 bwrite(out, BUF(buf), SZ(sz), (char*)&padc, 1);
142 if(!unsig && sign && num >= 0) {
143 bwrite(out, BUF(buf), SZ(sz), "+", 1);
146 bwrite(out, BUF(buf), SZ(sz), conv_buf, slen);
153 char c = va_arg(ap, int);
154 bwrite(out, BUF(buf), SZ(sz), &c, 1);
160 str = va_arg(ap, char*);
164 bwrite(out, BUF(buf), SZ(sz), str, slen);
168 for(i=slen; i<fwidth; i++) {
169 bwrite(out, BUF(buf), SZ(sz), (char*)&padc, 1);
173 bwrite(out, BUF(buf), SZ(sz), str, slen);
179 *va_arg(ap, int*) = cnum;
186 /* restore default conversion state */
219 const char *fw = fmt;
220 while(*fmt && isdigit(*fmt)) fmt++;
229 bwrite(out, BUF(buf), SZ(sz), (char*)fmt++, 1);
237 /* bwrite is called by intern_printf to transparently handle writing into a
238 * buffer or to the terminal
240 static void bwrite(int out, char *buf, unsigned long buf_sz, char *str, int sz)
245 if(buf_sz && buf_sz <= sz) sz = buf_sz;
247 memcpy(buf, str, sz);