IIC实例

/* * linux/lib/vsprintf.c * * Copyright (C) 1991, 1992 Linus Torvalds */ /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */ /* * Wirzenius wrote this portably, Torvalds fucked it up :-) */ /* * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com> * - changed to provide snprintf and vsnprintf functions * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de> * - scnprintf and vscnprintf */ //#include <stdarg.h> //#include <linux/module.h> #include "types.h" #include "kernel.h" #include "ctype.h" #include "string.h" #include "div64.h" #include "vsprintf.h" #define unlikely(x) __builtin_expect(!!(x), 0) /** * simple_strtoul - convert a string to an unsigned long * @cp: The start of the string * @endp: A pointer to the end of the parsed string will be placed here * @base: The number base to use */ unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base) { unsigned long result = 0,value; if (!base) { base = 10; if (*cp == '0') { base = 8; cp++; if ((toupper(*cp) == 'X') && isxdigit(cp[1])) { cp++; base = 16; } } } else if (base == 16) { if (cp[0] == '0' && toupper(cp[1]) == 'X') cp += 2; } while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : toupper(*cp)-'A'+10) < base) { result = result*base + value; cp++; } if (endp) *endp = (char *)cp; return result; } //EXPORT_SYMBOL(simple_strtoul); /** * simple_strtol - convert a string to a signed long * @cp: The start of the string * @endp: A pointer to the end of the parsed string will be placed here * @base: The number base to use */ long simple_strtol(const char *cp,char **endp,unsigned int base) { if(*cp=='-') return -simple_strtoul(cp+1,endp,base); return simple_strtoul(cp,endp,base); } //EXPORT_SYMBOL(simple_strtol); /** * simple_strtoull - convert a string to an unsigned long long * @cp: The start of the string * @endp: A pointer to the end of the parsed string will be placed here * @base: The number base to use */ unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base) { unsigned long long result = 0,value; if (!base) { base = 10; if (*cp == '0') { base = 8; cp++; if ((toupper(*cp) == 'X') && isxdigit(cp[1])) { cp++; base = 16; } } } else if (base == 16) { if (cp[0] == '0' && toupper(cp[1]) == 'X') cp += 2; } while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp) ? toupper(*cp) : *cp)-'A'+10) < base) { result = result*base + value; cp++; } if (endp) *endp = (char *)cp; return result; } //EXPORT_SYMBOL(simple_strtoull); /** * simple_strtoll - convert a string to a signed long long * @cp: The start of the string * @endp: A pointer to the end of the parsed string will be placed here * @base: The number base to use */ long long simple_strtoll(const char *cp,char **endp,unsigned int base) { if(*cp=='-') return -simple_strtoull(cp+1,endp,base); return simple_strtoull(cp,endp,base); } static int skip_atoi(const char **s) { int i=0; while (isdigit(**s)) i = i*10 + *((*s)++) - '0'; return i; } #define ZEROPAD 1 /* pad with zero */ #define SIGN 2 /* unsigned/signed long */ #define PLUS 4 /* show plus */ #define SPACE 8 /* space if plus */ #define LEFT 16 /* left justified */ #define SPECIAL 32 /* 0x */ #define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */ static char * number(char * buf, char * end, unsigned long long num, int base, int size, int precision, int type) { char c,sign,tmp[66]; const char *digits; static const char small_digits[] = "0123456789abcdefghijklmnopqrstuvwxyz"; static const char large_digits[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; int i; digits = (type & LARGE) ? large_digits : small_digits; if (type & LEFT) type &= ~ZEROPAD; if (base < 2 || base > 36) return NULL; c = (type & ZEROPAD) ? '0' : ' '; sign = 0; if (type & SIGN) { if ((signed long long) num < 0) { sign = '-'; num = - (signed long long) num; size--; } else if (type & PLUS) { sign = '+'; size--; } else if (type & SPACE) { sign = ' '; size--; } } if (type & SPECIAL) { if (base == 16) size -= 2; else if (base == 8) size--; } i = 0; if (num == 0) tmp[i++]='0'; else while (num != 0) tmp[i++] = digits[do_div(num,base)]; if (i > precision) precision = i; size -= precision; if (!(type&(ZEROPAD+LEFT))) { while(size-->0) { if (buf <= end) *buf = ' '; ++buf; } } if (sign) { if (buf <= end) *buf = sign; ++buf; } if (type & SPECIAL) { if (base==8) { if (buf <= end) *buf = '0'; ++buf; } else if (base==16) { if (buf <= end) *buf = '0'; ++buf; if (buf <= end) *buf = digits[33]; ++buf; } } if (!(type & LEFT)) { while (size-- > 0) { if (buf <= end) *buf = c; ++buf; } } while (i < precision--) { if (buf <= end) *buf = '0'; ++buf; } while (i-- > 0) { if (buf <= end) *buf = tmp[i]; ++buf; } while (size-- > 0) { if (buf <= end) *buf = ' '; ++buf; } return buf; } /** * vsnprintf - Format a string and place it in a buffer * @buf: The buffer to place the result into * @size: The size of the buffer, including the trailing null space * @fmt: The format string to use * @args: Arguments for the format string * * The return value is the number of characters which would * be generated for the given input, excluding the trailing * '\0', as per ISO C99. If you want to have the exact * number of characters written into @buf as return value * (not including the trailing '\0'), use vscnprintf. If the * return is greater than or equal to @size, the resulting * string is truncated. * * Call this function if you are already dealing with a va_list. * You probably want snprintf instead. */ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) { int len; unsigned long long num; int i, base; char *str, *end, c; const char *s; int flags; /* flags to number() */ int field_width; /* width of output field */ int precision; /* min. # of digits for integers; max number of chars for from string */ int qualifier; /* 'h', 'l', or 'L' for integer fields */ /* 'z' support added 23/7/1999 S.H. */ /* 'z' changed to 'Z' --davidm 1/25/99 */ /* Reject out-of-range values early */ if (unlikely((int) size < 0)) { /* There can be only one.. */ static int warn = 1; // WARN_ON(warn); warn = 0; return 0; } str = buf; end = buf + size - 1; if (end < buf - 1) { end = ((void *) -1); size = end - buf + 1; } for (; *fmt ; ++fmt) { if (*fmt != '%') { if (str <= end) *str = *fmt; ++str; continue; } /* process flags */ flags = 0; repeat: ++fmt; /* this also skips first '%' */ switch (*fmt) { case '-': flags |= LEFT; goto repeat; case '+': flags |= PLUS; goto repeat; case ' ': flags |= SPACE; goto repeat; case '#': flags |= SPECIAL; goto repeat; case '0': flags |= ZEROPAD; goto repeat; } /* get field width */ field_width = -1; if (isdigit(*fmt)) field_width = skip_atoi(&fmt); else if (*fmt == '*') { ++fmt; /* it's the next argument */ field_width = va_arg(args, int); if (field_width < 0) { field_width = -field_width; flags |= LEFT; } } /* get the precision */ precision = -1; if (*fmt == '.') { ++fmt; if (isdigit(*fmt)) precision = skip_atoi(&fmt); else if (*fmt == '*') { ++fmt; /* it's the next argument */ precision = va_arg(args, int); } if (precision < 0) precision = 0; } /* get the conversion qualifier */ qualifier = -1; if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || *fmt =='Z' || *fmt == 'z') { qualifier = *fmt; ++fmt; if (qualifier == 'l' && *fmt == 'l') { qualifier = 'L'; ++fmt; } } /* default base */ base = 10; switch (*fmt) { case 'c': if (!(flags & LEFT)) { while (--field_width > 0)