diff options
| -rw-r--r-- | toys/pending/printf.c | 196 |
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; + } + } } |