/****strtol.c - Contains C runtimes strtol and strtoul** Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.**Purpose:* strtol - convert ascii string to long signed integer* strtoul - convert ascii string to long unsigned integer********************************************************************************/#include <cruntime.h>#include <stdlib.h>#include <limits.h>#include <errno.h>#include <ctype.h>#include <mtdll.h>#include <setlocal.h>/****strtol, strtoul(nptr,endptr,ibase) - Convert ascii string to long un/signed* int.**Purpose:* Convert an ascii string to a long 32-bit value. The base* used for the caculations is supplied by the caller. The base* must be in the range 0, 2-36. If a base of 0 is supplied, the* ascii string must be examined to determine the base of the* number:* (a) First char = '0', second char = 'x' or 'X',* use base 16.* (b) First char = '0', use base 8* (c) First char in range '1' - '9', use base 10.** If the 'endptr' value is non-NULL, then strtol/strtoul places* a pointer to the terminating character in this value.* See ANSI standard for details**Entry:* nptr == NEAR/FAR pointer to the start of string.* endptr == NEAR/FAR pointer to the end of the string.* ibase == integer base to use for the calculations.** string format: [whitespace] [sign] [0] [x] [digits/letters]**Exit:* Good return:* result** Overflow return:* strtol -- LONG_MAX or LONG_MIN* strtoul -- ULONG_MAX* strtol/strtoul -- errno == ERANGE** No digits or bad base return:* 0* endptr = nptr***Exceptions:* None.*******************************************************************************//* flag values */#define FL_UNSIGNED 1 /* strtoul called */#define FL_NEG 2 /* negative sign found */#define FL_OVERFLOW 4 /* overflow occured */#define FL_READDIGIT 8 /* we've read at least one correct digit */static unsigned long __cdecl strtoxl ( const char *nptr, const char **endptr, int ibase, int flags ){ const char *p; char c; unsigned long number; unsigned digval; unsigned long maxval;#ifdef _MT _ptiddata ptd = _getptd(); pthreadlocinfo ptloci = ptd->ptlocinfo; __UPDATE_LOCALE(ptd, ptloci);#endif /* _MT */ p = nptr; /* p is our scanning pointer */ number = 0; /* start with zero */ c = *p++; /* read char */#ifdef _MT while ( __isspace_mt(ptloci, (int)(unsigned char)c) )#else /* _MT */ while ( isspace((int)(unsigned char)c) )#endif /* _MT */ c = *p++; /* skip whitespace */ if (c == '-') { flags |= FL_NEG; /* remember minus sign */ c = *p++; } else if (c == '+') c = *p++; /* skip sign */ if (ibase < 0 || ibase == 1 || ibase > 36) { /* bad base! */ if (endptr) /* store beginning of string in endptr */ *endptr = nptr; return 0L; /* return 0 */ } else if (ibase == 0) { /* determine base free-lance, based on first two chars of string */ if (c != '0') ibase = 10; else if (*p == 'x' || *p == 'X') ibase = 16; else ibase = 8; } if (ibase == 16) { /* we might have 0x in front of number; remove if there */ if (c == '0' && (*p == 'x' || *p == 'X')) { ++p; c = *p++; /* advance past prefix */ } } /* if our number exceeds this, we will overflow on multiply */ maxval = ULONG_MAX / ibase; for (;;) { /* exit in middle of loop */ /* convert c to value */ if ( __ascii_isdigit((int)(unsigned char)c) ) digval = c - '0'; else if ( __ascii_isalpha((int)(unsigned char)c) ) digval = __ascii_toupper(c) - 'A' + 10; else break; if (digval >= (unsigned)ibase) break; /* exit loop if bad digit found */ /* record the fact we have read one digit */ flags |= FL_READDIGIT; /* we now need to compute number = number * base + digval, but we need to know if overflow occured. This requires a tricky pre-check. */ if (number < maxval || (number == maxval && (unsigned long)digval <= ULONG_MAX % ibase)) { /* we won't overflow, go ahead and multiply */ number = number * ibase + digval; } else { /* we would have overflowed -- set the overflow flag */ flags |= FL_OVERFLOW; } c = *p++; /* read next digit */ } --p; /* point to place that stopped scan */ if (!(flags & FL_READDIGIT)) { /* no number there; return 0 and point to beginning of string */ if (endptr) /* store beginning of string in endptr later on */ p = nptr; number = 0L; /* return 0 */ } else if ( (flags & FL_OVERFLOW) || ( !(flags & FL_UNSIGNED) && ( ( (flags & FL_NEG) && (number > -LONG_MIN) ) || ( !(flags & FL_NEG) && (number > LONG_MAX) ) ) ) ) { /* overflow or signed overflow occurred */ errno = ERANGE; if ( flags & FL_UNSIGNED ) number = ULONG_MAX; else if ( flags & FL_NEG ) number = (unsigned long)(-LONG_MIN); else number = LONG_MAX; } if (endptr != NULL) /* store pointer to char that stopped the scan */ *endptr = p; if (flags & FL_NEG) /* negate result if there was a neg sign */ number = (unsigned long)(-(long)number); return number; /* done. */}long __cdecl strtol ( const char *nptr, char **endptr, int ibase ){ return (long) strtoxl(nptr, endptr, ibase, 0);}unsigned long __cdecl strtoul ( const char *nptr, char **endptr, int ibase ){ return strtoxl(nptr, endptr, ibase, FL_UNSIGNED);}