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-rw-r--r--toys/pending/printf.c196
1 files changed, 73 insertions, 123 deletions
diff --git a/toys/pending/printf.c b/toys/pending/printf.c
index 3ec20813..b683128f 100644
--- a/toys/pending/printf.c
+++ b/toys/pending/printf.c
@@ -27,19 +27,14 @@ GLOBALS(
int encountered;
)
-// Calculate width and precision from format string
-static int get_w_p()
+// Detect matching character (return true/valse) and advance pointer if match.
+static int eat(char **s, char c)
{
- char *ptr, *str = *toys.optargs;
+ int x = (**s == c);
- errno = 0;
- if (*str == '-') str++;
- long value = strtol(str, &ptr, 10);
- if (errno || (ptr && (*ptr != '\0' || ptr == str)))
- perror_msg("Invalid num %s", *toys.optargs);
- if (*--str == '-') return (int)(-1 * value);
+ if (x) ++*s;
- return value;
+ return x;
}
// Add ll and L to Interger and floating point formats respectively.
@@ -101,133 +96,88 @@ static void print(char *fmt, int w, int p)
if (format) free(format);
}
-// Handle the escape sequences.
+// Parse escape sequences.
static int handle_slash(char **esc_val)
{
char *ptr = *esc_val;
- int esc_length = 0;
- unsigned base = 0, num = 0, result = 0, count = 0;
-
- /*
- * Hex escape sequence have only 1 or 2 digits, xHH. Oct escape sequence
- * have 1,2 or 3 digits, xHHH. Leading "0" (\0HHH) we are ignoring.
- */
- if (*ptr == 'x') {
- ptr++;
- esc_length++;
- base = 16;
- } else if (isdigit(*ptr)) base = 8;
+ int len = 1, base = 0;
+ unsigned result = 0;
+
+ if (*ptr == 'c') xexit();
+
+ // 0x12 hex escapes have 1-2 digits, \123 octal escapes have 1-3 digits.
+ if (eat(&ptr, 'x')) base = 16;
+ else if (*ptr >= '0' && *ptr <= '8') base = 8;
+ len += (base-8)/8;
+
+ // Not a hex or octal escape? (This catches trailing \)
+ if (!len) {
+ if (!(result = unescape(*ptr))) result = '\\';
+ else ++*esc_val;
+
+ return result;
+ }
- while (esc_length < 3 && base) {
- num = tolower(*ptr) - '0';
- if (num > 10) num += ('0' - 'a' + 10);
+ while (len) {
+ unsigned num = tolower(*ptr)-'0';
+
+ if (num > 10) num += '0'-'a'+10;
if (num >= base) {
- if (base == 16) {
- esc_length--;
- if (!esc_length) {// Invalid hex value eg. /xvd, print as it is /xvd
- result = '\\';
- ptr--;
- }
+ // Don't parse invalid hex value ala "\xvd", print it verbatim
+ if (base == 16 && len == 2) {
+ ptr--;
+ result = '\\';
}
break;
}
- esc_length++;
- count = result = (count * base) + num;
+ result = (result*base)+num;
ptr++;
- }
- if (base) ptr--;
- else if (!(result = unescape(*ptr))) {
- result = '\\';
- ptr--; // Let pointer pointing to / we will increment after returning.
+ len--;
}
*esc_val = ptr;
- return (char)result;
-}
-// Handle "%b" option with '\' interpreted.
-static void print_esc_str(char *str)
-{
- for (; *str; str++) {
- if (*str == '\\') {
- str++;
- xputc(handle_slash(&str)); //print corresponding char
- } else xputc(*str);
- }
-}
-
-// Parse the format string and print.
-static void parse_print(char *format)
-{
- char *start, *p, *f = format;
- int len = 0, width = 0, prec = 0;
-
- while (*f) {
- if (*f == '%') {
- start = f++;
- len++;
- if (*f == '%') {
- xputc('%');
- break;
- }
- if (*f == 'b') {
- if (*toys.optargs) {
- print_esc_str(*toys.optargs++);
- TT.encountered = 1;
- } else print_esc_str("");
- break;
- }
- if (strchr("-+# ", *f)) f++, len++;
- if (*f == '*') {
- f++, len++;
- if (*toys.optargs) {
- width = get_w_p();
- toys.optargs++;
- }
- } else while (isdigit(*f)) f++, len++;
-
- if (*f == '.') {
- f++, len++;
- if (*f == '*') {
- f++, len++;
- if (*toys.optargs) {
- prec = get_w_p();
- toys.optargs++;
- }
- } else {
- while (isdigit(*f)) f++, len++;
- }
- }
- if (!(p = strchr("diouxXfeEgGcs", *f)))
- perror_exit("bad format@%ld", f-format);
- else {
- len++;
- TT.hv_p = strstr(start, ".*");
- TT.hv_w = strchr(start, '*');
- //pitfall: handle diff b/w * and .*
- if ((TT.hv_w-1) == TT.hv_p) TT.hv_w = NULL;
- memcpy((p = xzalloc(len+1)), start, len);
- print(p+len-1, width, prec);
- if (*toys.optargs) toys.optargs++;
- free(p);
- p = NULL;
- }
- TT.encountered = 1;
- } else if (*f == '\\' && f[1]) {
- if (*++f == 'c') exit(0); //Got '\c', so no further output
- xputc(handle_slash(&f));
- } else xputc(*f);
- f++;
- len = 0;
- }
+ return (char)result;
}
void printf_main(void)
{
- char *format = *toys.optargs++;
-
- TT.encountered = 0;
- parse_print(format); //printf acc. to format.
- //Re-use FORMAT arg as necessary to convert all given ARGS.
- while (*toys.optargs && TT.encountered) parse_print(format);
- xflush();
+ char *format = *toys.optargs, **arg = toys.optargs+1, *f, *p;
+
+ for (f = format; *f; f++) {
+ if (eat(&f, '\\')) putchar(handle_slash(&f));
+ else if (*f != '%' || *++f == '%') xputc(*f);
+ else if (*f == 'b')
+ for (p = *arg ? *(arg++) : ""; *p; p++)
+ putchar(eat(&p, '\\') ? handle_slash(&p) : *p);
+ else {
+ char *start = f;
+ int wp[2], i;
+
+ // todo: we currently ignore these?
+ if (strchr("-+# ", *f)) f++;
+ memset(wp, 0, 8);
+ for (i=0; i<2; i++) {
+ if (eat(&f, '*')) {
+ if (*arg) wp[i] = atolx(*(arg++));
+ } else while (isdigit(*f)) f++;
+ if (!eat(&f, '.')) break;
+ }
+ if (!(p = strchr("diouxXfeEgGcs", *f)))
+ perror_exit("bad format@%ld", f-format);
+ else {
+ int len = f-start;
+
+ TT.hv_p = strstr(start, ".*");
+ TT.hv_w = strchr(start, '*');
+ //pitfall: handle diff b/w * and .*
+ if ((TT.hv_w-1) == TT.hv_p) TT.hv_w = NULL;
+ memcpy((p = xzalloc(len+1)), start, len);
+ print(p+len-1, wp[0], wp[1]);
+ if (*arg) arg++;
+ free(p);
+ p = NULL;
+ }
+ TT.encountered = 1;
+ }
+ }
}