1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/libc/printf.c	Sat Feb 11 08:56:42 2017 +0200
     1.3 @@ -0,0 +1,323 @@
     1.4 +#include <stdio.h>
     1.5 +#include <string.h>
     1.6 +#include <stdlib.h>
     1.7 +#include <ctype.h>
     1.8 +#include <stdarg.h>
     1.9 +
    1.10 +static void bwrite(char *buf, size_t buf_sz, char *str, int sz);
    1.11 +static int intern_printf(char *buf, size_t sz, const char *fmt, va_list ap);
    1.12 +static void itoa(int val, char *buf, int base);
    1.13 +static void utoa(unsigned int val, char *buf, int base);
    1.14 +
    1.15 +
    1.16 +int putchar(int c)
    1.17 +{
    1.18 +	/* TODO */
    1.19 +	return c;
    1.20 +}
    1.21 +
    1.22 +int puts(const char *s)
    1.23 +{
    1.24 +	while(*s) {
    1.25 +		putchar(*s++);
    1.26 +	}
    1.27 +	putchar('\n');
    1.28 +	return 0;
    1.29 +}
    1.30 +
    1.31 +/* -- printf and friends -- */
    1.32 +
    1.33 +static char *convc = "dioxXucsfeEgGpn%";
    1.34 +
    1.35 +#define IS_CONV(c)	strchr(convc, c)
    1.36 +
    1.37 +int printf(const char *fmt, ...)
    1.38 +{
    1.39 +	int res;
    1.40 +	va_list ap;
    1.41 +
    1.42 +	va_start(ap, fmt);
    1.43 +	res = intern_printf(0, 0, fmt, ap);
    1.44 +	va_end(ap);
    1.45 +	return res;
    1.46 +}
    1.47 +
    1.48 +int vprintf(const char *fmt, va_list ap)
    1.49 +{
    1.50 +	return intern_printf(0, 0, fmt, ap);
    1.51 +}
    1.52 +
    1.53 +int sprintf(char *buf, const char *fmt, ...)
    1.54 +{
    1.55 +	int res;
    1.56 +	va_list ap;
    1.57 +
    1.58 +	va_start(ap, fmt);
    1.59 +	res = intern_printf(buf, 0, fmt, ap);
    1.60 +	va_end(ap);
    1.61 +	return res;
    1.62 +}
    1.63 +
    1.64 +int vsprintf(char *buf, const char *fmt, va_list ap)
    1.65 +{
    1.66 +	return intern_printf(buf, 0, fmt, ap);
    1.67 +}
    1.68 +
    1.69 +int snprintf(char *buf, size_t sz, const char *fmt, ...)
    1.70 +{
    1.71 +	int res;
    1.72 +	va_list ap;
    1.73 +
    1.74 +	va_start(ap, fmt);
    1.75 +	res = intern_printf(buf, sz, fmt, ap);
    1.76 +	va_end(ap);
    1.77 +	return res;
    1.78 +}
    1.79 +
    1.80 +int vsnprintf(char *buf, size_t sz, const char *fmt, va_list ap)
    1.81 +{
    1.82 +	return intern_printf(buf, sz, fmt, ap);
    1.83 +}
    1.84 +
    1.85 +
    1.86 +/* intern_printf provides all the functionality needed by all the printf
    1.87 + * variants.
    1.88 + * - buf: optional buffer onto which the formatted results are written. If null
    1.89 + *   then the output goes to the terminal through putchar calls. This is used
    1.90 + *   by the (v)sprintf variants which write to an array of char.
    1.91 + * - sz: optional maximum size of the output, 0 means unlimited. This is used
    1.92 + *   by the (v)snprintf variants to avoid buffer overflows.
    1.93 + * The rest are obvious, format string and variable argument list.
    1.94 + */
    1.95 +
    1.96 +#define BUF(x)	((x) ? (x) + cnum : (x))
    1.97 +#define SZ(x)	((x) ? (x) - cnum : (x))
    1.98 +
    1.99 +static int intern_printf(char *buf, size_t sz, const char *fmt, va_list ap)
   1.100 +{
   1.101 +	char conv_buf[32];
   1.102 +	char *str;
   1.103 +	int i, slen;
   1.104 +	const char *fstart = 0;
   1.105 +
   1.106 +	/* state */
   1.107 +	int cnum = 0;
   1.108 +	int base = 10;
   1.109 +	int alt = 0;
   1.110 +	int fwidth = 0;
   1.111 +	int padc = ' ';
   1.112 +	int sign = 0;
   1.113 +	int left_align = 0;	/* not implemented yet */
   1.114 +	int hex_caps = 0;
   1.115 +	int unsig = 0;
   1.116 +
   1.117 +	while(*fmt) {
   1.118 +		if(*fmt == '%') {
   1.119 +			fstart = fmt++;
   1.120 +			continue;
   1.121 +		}
   1.122 +
   1.123 +		if(fstart) {
   1.124 +			if(IS_CONV(*fmt)) {
   1.125 +				switch(*fmt) {
   1.126 +				case 'X':
   1.127 +					hex_caps = 1;
   1.128 +
   1.129 +				case 'x':
   1.130 +				case 'p':
   1.131 +					base = 16;
   1.132 +
   1.133 +					if(alt) {
   1.134 +						bwrite(BUF(buf), SZ(sz), "0x", 2);
   1.135 +					}
   1.136 +
   1.137 +				case 'u':
   1.138 +					unsig = 1;
   1.139 +
   1.140 +					if(0) {
   1.141 +				case 'o':
   1.142 +						base = 8;
   1.143 +
   1.144 +						if(alt) {
   1.145 +							bwrite(BUF(buf), SZ(sz), "0", 1);
   1.146 +						}
   1.147 +					}
   1.148 +
   1.149 +				case 'd':
   1.150 +				case 'i':
   1.151 +					if(unsig) {
   1.152 +						utoa(va_arg(ap, unsigned int), conv_buf, base);
   1.153 +					} else {
   1.154 +						itoa(va_arg(ap, int), conv_buf, base);
   1.155 +					}
   1.156 +					if(hex_caps) {
   1.157 +						for(i=0; conv_buf[i]; i++) {
   1.158 +							conv_buf[i] = toupper(conv_buf[i]);
   1.159 +						}
   1.160 +					}
   1.161 +
   1.162 +					slen = strlen(conv_buf);
   1.163 +					for(i=slen; i<fwidth; i++) {
   1.164 +						bwrite(BUF(buf), SZ(sz), (char*)&padc, 1);
   1.165 +						cnum++;
   1.166 +					}
   1.167 +
   1.168 +					bwrite(BUF(buf), SZ(sz), conv_buf, strlen(conv_buf));
   1.169 +					cnum += slen;
   1.170 +					break;
   1.171 +
   1.172 +				case 'c':
   1.173 +					{
   1.174 +						char c = va_arg(ap, int);
   1.175 +						bwrite(BUF(buf), SZ(sz), &c, 1);
   1.176 +						cnum++;
   1.177 +					}
   1.178 +					break;
   1.179 +
   1.180 +				case 's':
   1.181 +					str = va_arg(ap, char*);
   1.182 +					slen = strlen(str);
   1.183 +
   1.184 +					for(i=slen; i<fwidth; i++) {
   1.185 +						bwrite(BUF(buf), SZ(sz), (char*)&padc, 1);
   1.186 +						cnum++;
   1.187 +					}
   1.188 +					bwrite(BUF(buf), SZ(sz), str, slen);
   1.189 +					cnum += slen;
   1.190 +					break;
   1.191 +
   1.192 +				case 'n':
   1.193 +					*va_arg(ap, int*) = cnum;
   1.194 +					break;
   1.195 +
   1.196 +				default:
   1.197 +					break;
   1.198 +				}
   1.199 +
   1.200 +				/* restore default conversion state */
   1.201 +				base = 10;
   1.202 +				alt = 0;
   1.203 +				fwidth = 0;
   1.204 +				padc = ' ';
   1.205 +				hex_caps = 0;
   1.206 +
   1.207 +				fstart = 0;
   1.208 +				fmt++;
   1.209 +			} else {
   1.210 +				switch(*fmt) {
   1.211 +				case '#':
   1.212 +					alt = 1;
   1.213 +					break;
   1.214 +
   1.215 +				case '+':
   1.216 +					sign = 1;
   1.217 +					break;
   1.218 +
   1.219 +				case '-':
   1.220 +					left_align = 1;
   1.221 +					break;
   1.222 +
   1.223 +				case 'l':
   1.224 +				case 'L':
   1.225 +					break;
   1.226 +
   1.227 +				case '0':
   1.228 +					padc = '0';
   1.229 +					break;
   1.230 +
   1.231 +				default:
   1.232 +					if(isdigit(*fmt)) {
   1.233 +						const char *fw = fmt;
   1.234 +						while(*fmt && isdigit(*fmt)) fmt++;
   1.235 +
   1.236 +						fwidth = atoi(fw);
   1.237 +						continue;
   1.238 +					}
   1.239 +				}
   1.240 +				fmt++;
   1.241 +			}
   1.242 +		} else {
   1.243 +			bwrite(BUF(buf), SZ(sz), (char*)fmt++, 1);
   1.244 +			cnum++;
   1.245 +		}
   1.246 +	}
   1.247 +
   1.248 +	return 0;
   1.249 +}
   1.250 +
   1.251 +
   1.252 +/* bwrite is called by intern_printf to transparently handle writing into a
   1.253 + * buffer (if buf is non-null) or to the terminal (if buf is null).
   1.254 + */
   1.255 +static void bwrite(char *buf, size_t buf_sz, char *str, int sz)
   1.256 +{
   1.257 +	if(buf) {
   1.258 +		if(buf_sz && buf_sz <= sz) sz = buf_sz - 1;
   1.259 +		memcpy(buf, str, sz);
   1.260 +
   1.261 +		buf[sz] = 0;
   1.262 +	} else {
   1.263 +		int i;
   1.264 +		for(i=0; i<sz; i++) {
   1.265 +			putchar(*str++);
   1.266 +		}
   1.267 +	}
   1.268 +}
   1.269 +
   1.270 +
   1.271 +static void itoa(int val, char *buf, int base)
   1.272 +{
   1.273 +	static char rbuf[16];
   1.274 +	char *ptr = rbuf;
   1.275 +	int neg = 0;
   1.276 +
   1.277 +	if(val < 0) {
   1.278 +		neg = 1;
   1.279 +		val = -val;
   1.280 +	}
   1.281 +
   1.282 +	if(val == 0) {
   1.283 +		*ptr++ = '0';
   1.284 +	}
   1.285 +
   1.286 +	while(val) {
   1.287 +		int digit = val % base;
   1.288 +		*ptr++ = digit < 10 ? (digit + '0') : (digit - 10 + 'a');
   1.289 +		val /= base;
   1.290 +	}
   1.291 +
   1.292 +	if(neg) {
   1.293 +		*ptr++ = '-';
   1.294 +	}
   1.295 +
   1.296 +	ptr--;
   1.297 +
   1.298 +	while(ptr >= rbuf) {
   1.299 +		*buf++ = *ptr--;
   1.300 +	}
   1.301 +	*buf = 0;
   1.302 +}
   1.303 +
   1.304 +static void utoa(unsigned int val, char *buf, int base)
   1.305 +{
   1.306 +	static char rbuf[16];
   1.307 +	char *ptr = rbuf;
   1.308 +
   1.309 +	if(val == 0) {
   1.310 +		*ptr++ = '0';
   1.311 +	}
   1.312 +
   1.313 +	while(val) {
   1.314 +		unsigned int digit = val % base;
   1.315 +		*ptr++ = digit < 10 ? (digit + '0') : (digit - 10 + 'a');
   1.316 +		val /= base;
   1.317 +	}
   1.318 +
   1.319 +	ptr--;
   1.320 +
   1.321 +	while(ptr >= rbuf) {
   1.322 +		*buf++ = *ptr--;
   1.323 +	}
   1.324 +	*buf = 0;
   1.325 +}
   1.326 +