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Diffstat (limited to 'missing_d/strtoul.c')
| -rw-r--r-- | missing_d/strtoul.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/missing_d/strtoul.c b/missing_d/strtoul.c new file mode 100644 index 00000000..ccabfbeb --- /dev/null +++ b/missing_d/strtoul.c @@ -0,0 +1,223 @@ +/* + * Very simple implementation of strtoul() for gawk, + * for old systems. Descriptive prose from the Linux man page. + * + * May 2004 + */ + +/* #define TEST 1 */ + +#ifdef TEST +#include <stdio.h> +#include <stdlib.h> +#include <ctype.h> +#include <string.h> +#include <errno.h> +#include <limits.h> +#define TRUE 1 +#define FALSE 0 +#define strtoul mystrtoul +#endif + +#ifndef ULONG_MAX +#define ULONG_MAX (~ 0UL) +#endif + +unsigned long int +strtoul(nptr, endptr, base) +const char *nptr; +char **endptr; +int base; +{ + static char lower[] = "abcdefghijklmnopqrstuvwxyz"; + + unsigned long result = 0UL; + char *nptr_orig = (char *) nptr; + int neg = FALSE; + char *cp, c; + int val; + int sawdigs = FALSE; + + /* + * The strtoul() function converts the initial part of the + * string in nptr to an unsigned long integer value according + * to the given base, which must be between 2 and 36 inclusive, + * or be the special value 0. + */ + + if ((base != 0 && (base < 2 || base > 36)) || nptr == NULL) { + if (endptr != NULL) + *endptr = nptr_orig; + errno = EINVAL; + return 0; + } + + /* + * The string must [sic] begin with an arbitrary amount of white space + * (as determined by isspace(3)) followed by a single optional + * `+' or `-' sign. + */ + while (isspace(*nptr)) + nptr++; + + if (*nptr == '+') + nptr++; + else if (*nptr == '-') { + nptr++; + neg = TRUE; + } + + /* + * If base is zero or 16, the string may then include a `0x' prefix, + * and the number will be read in base 16; otherwise, a zero base is + * taken as 10 (decimal) unless the next character is `0', in which + * case it is taken as 8 (octal). + */ + if ((base == 0 || base == 16) + && nptr[0] == '0' + && (nptr[1] == 'x' || nptr[1] == 'X')) { + base = 16; /* force it */ + nptr += 2; /* skip 0x */ + } else if ((base == 0 || base == 8) && nptr[0] == '0') { + base = 8; + nptr++; + } else if (base == 0) + base = 10; + + /* + * The remainder of the string is converted to an unsigned long int + * value in the obvious manner, stopping at the first character + * which is not a valid digit in the given base. (In bases above 10, + * the letter `A' in either upper or lower case represents 10, + * `B' represents 11, and so forth, with `Z' representing 35.) + */ + for (; *nptr != '\0'; nptr++) { + c = *nptr; +#if ENABLE_NLS && defined(HAVE_LOCALE_H) + if (base == 10 + && loc.thousands_sep != NULL + && loc.thousands_sep[0] != '\0' + && c == loc.thousands_sep[0]) + continue; +#endif + switch (c) { + case '0': case '1': case '2': + case '3': case '4': case '5': + case '6': case '7': case '8': + case '9': + val = c - '0'; + if (val >= base) /* even base 2 allowed ... */ + goto out; + result *= base; + result += val; + sawdigs = TRUE; + break; + case 'A': case 'B': case 'C': case 'D': case 'E': + case 'F': case 'G': case 'H': case 'I': case 'J': + case 'K': case 'L': case 'M': case 'N': case 'O': + case 'P': case 'Q': case 'R': case 'S': case 'T': + case 'U': case 'V': case 'W': case 'X': case 'Y': + case 'Z': + c += 'a' - 'A'; /* downcase */ + /* fall through */ + case 'a': case 'b': case 'c': case 'd': case 'e': + case 'f': case 'g': case 'h': case 'i': case 'j': + case 'k': case 'l': case 'm': case 'n': case 'o': + case 'p': case 'q': case 'r': case 's': case 't': + case 'u': case 'v': case 'w': case 'x': case 'y': + case 'z': + cp = strchr(lower, c); + val = cp - lower; + val += 10; /* 'a' == 10 */ + if (val >= base) + goto out; + result *= base; + result += val; + sawdigs = TRUE; + break; + default: + goto out; + } + } +out: + /* + * If endptr is not NULL, strtoul() stores the address of the + * first invalid character in *endptr. If there were no digits + * at all, strtoul() stores the original value of nptr in *endptr + * (and returns 0). In particular, if *nptr is not `\0' but + * **endptr is `\0' on return, the entire string is valid. + */ + if (endptr != NULL) { + if (! sawdigs) { + *endptr = nptr_orig; + return 0; + } else + *endptr = (char *) nptr; + } + + /* + * RETURN VALUE + * The strtoul() function returns either the result of the + * conversion or, if there was a leading minus sign, the + * negation of the result of the conversion, unless the original + * (non-negated) value would overflow; in the latter case, + * strtoul() returns ULONG_MAX and sets the global variable errno + * to ERANGE. + */ + + /* + * ADR: This computation is probably bogus. If it's a + * problem, upgrade to a modern system. + */ + if (neg && result == ULONG_MAX) { + errno = ERANGE; + return ULONG_MAX; + } else if (neg) + result = -result; + + return result; +} + +#ifdef TEST +#undef strtoul +int main(void) +{ + char *endptr; + unsigned long res1, res2; + + res1 = strtoul("0xdeadBeeF", & endptr, 0), + res2 = mystrtoul("0xdeadBeeF", & endptr, 0), +printf("(real,my)strtoul(\"0xdeadBeeF\", & endptr, 0) is %lu, %lu *endptr = %d\n", + res1, res2, *endptr); + + res1 = strtoul("0101101", & endptr, 2), + res2 = mystrtoul("0101101", & endptr, 2), +printf("(real,my)strtoul(\"0101101\", & endptr, 2) is %lu, %lu *endptr = %d\n", + res1, res2, *endptr); + + res1 = strtoul("01011012", & endptr, 2), + res2 = mystrtoul("01011012", & endptr, 2), +printf("(real,my)strtoul(\"01011012\", & endptr, 2) is %lu, %lu *endptr = %d\n", + res1, res2, *endptr); + + res1 = strtoul(" +42a", & endptr, 0), + res2 = mystrtoul(" +42a", & endptr, 0), +printf("(real,my)strtoul(\" +42a\", & endptr, 0) is %lu, %lu *endptr = %d\n", + res1, res2, *endptr); + + res1 = strtoul("0377", & endptr, 0), + res2 = mystrtoul("0377", & endptr, 0), +printf("(real,my)strtoul(\"0377\", & endptr, 0) is %lu, %lu *endptr = %d\n", + res1, res2, *endptr); + + res1 = strtoul("Z", & endptr, 36), + res2 = mystrtoul("Z", & endptr, 36), +printf("(real,my)strtoul(\"Z\", & endptr, 36) is %lu, %lu *endptr = %d\n", + res1, res2, *endptr); + + res1 = strtoul("qZ*", & endptr, 36), + res2 = mystrtoul("qZ*", & endptr, 36), +printf("(real,my)strtoul(\"qZ*\", & endptr, 36) is %lu, %lu *endptr = %d\n", + res1, res2, *endptr); +} +#endif |