/* * 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 <linux/types.h> #include <linux/string.h> #include <linux/ctype.h> #include <linux/kernel.h> #include <linux/kallsyms.h> #include <linux/uaccess.h> #include <linux/ioport.h> #include <asm/page.h> /* for PAGE_SIZE */ #include <asm/div64.h> #include <asm/sections.h> /* for dereference_function_descriptor() */ /* Works only for digits and letters, but small and fast */ #define TOLOWER(x) ((x) | 0x20) static unsigned int simple_guess_base(const char *cp) { if (cp[0] == '0') { if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2])) return 16; else return 8; } else { return 10; } } /** * 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; if (!base) base = simple_guess_base(cp); if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x') cp += 2; while (isxdigit(*cp)) { unsigned int value; value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10; if (value >= base) break; 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; if (!base) base = simple_guess_base(cp); if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x') cp += 2; while (isxdigit(*cp)) { unsigned int value; value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10; if (value >= base) break; 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); } /** * strict_strtoul - convert a string to an unsigned long strictly * @cp: The string to be converted * @base: The number base to use * @res: The converted result value * * strict_strtoul converts a string to an unsigned long only if the * string is really an unsigned long string, any string containing * any invalid char at the tail will be rejected and -EINVAL is returned, * only a newline char at the tail is acceptible because people generally * change a module parameter in the following way: * * echo 1024 > /sys/module/e1000/parameters/copybreak * * echo will append a newline to the tail. * * It returns 0 if conversion is successful and *res is set to the converted * value, otherwise it returns -EINVAL and *res is set to 0. * * simple_strtoul just ignores the successive invalid characters and * return the converted value of prefix part of the string. */ int strict_strtoul(const char *cp, unsigned int base, unsigned long *res) { char *tail; unsigned long val; size_t len; *res = 0; len = strlen(cp); if (len == 0) return -EINVAL; val = simple_strtoul(cp, &tail, base); if ((*tail == '\0') || ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) { *res = val; return 0; } return -EINVAL; } EXPORT_SYMBOL(strict_strtoul); /** * strict_strtol - convert a string to a long strictly * @cp: The string to be converted * @base: The number base to use * @res: The converted result value * * strict_strtol is similiar to strict_strtoul, but it allows the first * character of a string is '-'. * * It returns 0 if conversion is successful and *res is set to the converted * value, otherwise it returns -EINVAL and *res is set to 0. */ int strict_strtol(const char *cp, unsigned int base, long *res) { int ret; if (*cp == '-') { ret = strict_strtoul(cp + 1, base, (unsigned long *)res); if (!ret) *res = -(*res); } else { ret = strict_strtoul(cp, base, (unsigned long *)res); } return ret; } EXPORT_SYMBOL(strict_strtol); /** * strict_strtoull - convert a string to an unsigned long long strictly * @cp: The string to be converted * @base: The number base to use * @res: The converted result value * * strict_strtoull converts a string to an unsigned long long only if the * string is really an unsigned long long string, any string containing * any invalid char at the tail will be rejected and -EINVAL is returned, * only a newline char at the tail is acceptible because people generally * change a module parameter in the following way: * * echo 1024 > /sys/module/e1000/parameters/copybreak * * echo will append a newline to the tail of the string. * * It returns 0 if conversion is successful and *res is set to the converted * value, otherwise it returns -EINVAL and *res is set to 0. * * simple_strtoull just ignores the successive invalid characters and * return the converted value of prefix part of the string. */ int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res) { char *tail; unsigned long long val; size_t len; *res = 0; len = strlen(cp); if (len == 0) return -EINVAL; val = simple_strtoull(cp, &tail, base); if ((*tail == '\0') || ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) { *res = val; return 0; } return -EINVAL; } EXPORT_SYMBOL(strict_strtoull); /** * strict_strtoll - convert a string to a long long strictly * @cp: The string to be converted * @base: The number base to use * @res: The converted result value * * strict_strtoll is similiar to strict_strtoull, but it allows the first * character of a string is '-'. * * It returns 0 if conversion is successful and *res is set to the converted * value, otherwise it returns -EINVAL and *res is set to 0. */ int strict_strtoll(const char *cp, unsigned int base, long long *res) { int ret; if (*cp == '-') { ret = strict_strtoull(cp + 1, base, (unsigned long long *)res); if (!ret) *res = -(*res); } else { ret = strict_strtoull(cp, base, (unsigned long long *)res); } return ret; } EXPORT_SYMBOL(strict_strtoll); static int skip_atoi(const char **s) { int i=0; while (isdigit(**s)) i = i*10 + *((*s)++) - '0'; return i; } /* Decimal conversion is by far the most typical, and is used * for /proc and /sys data. This directly impacts e.g. top performance * with many processes running. We optimize it for speed * using code from * http://www.cs.uiowa.edu/~jones/bcd/decimal.html * (with permission from the author, Douglas W. Jones). */ /* Formats correctly any integer in [0,99999]. * Outputs from one to five digits depending on input. * On i386 gcc 4.1.2 -O2: ~250 bytes of code. */ static char* put_dec_trunc(char *buf, unsigned q) { unsigned d3, d2, d1, d0; d1 = (q>>4) & 0xf; d2 = (q>>8) & 0xf; d3 = (q>>12); d0 = 6*(d3 + d2 + d1) + (q & 0xf); q = (d0 * 0xcd) >> 11; d0 = d0 - 10*q; *buf++ = d0 + '0'; /* least significant digit */ d1 = q + 9*d3 + 5*d2 + d1; if (d1 != 0) { q = (d1 * 0xcd) >> 11; d1 = d1 - 10*q; *buf++ = d1 + '0'; /* next digit */ d2 = q + 2*d2; if ((d2 != 0) || (d3 != 0)) { q = (d2 * 0xd) >> 7; d2 = d2 - 10*q; *buf++ = d2 + '0'; /* next digit */ d3 = q + 4*d3; if (d3 != 0) { q = (d3 * 0xcd) >> 11; d3 = d3 - 10*q; *buf++ = d3 + '0'; /* next digit */ if (q != 0) *buf++ = q + '0'; /* most sign. digit */ } } } return buf; } /* Same with if's removed. Always emits five digits */ static char* put_dec_full(char *buf, unsigned q) { /* BTW, if q is in [0,9999], 8-bit ints will be enough, */ /* but anyway, gcc produces better code with full-sized ints */ unsigned d3, d2, d1, d0; d1 = (q>>4) & 0xf; d2 = (q>>8) & 0xf; d3 = (q>>12); /* Possible ways to approx. divide by 10 */ /* gcc -O2 replaces multiply with shifts and adds */ // (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386) // (x * 0x67) >> 10: 1100111 // (x * 0x34) >> 9: 110100 - same // (x * 0x1a) >> 8: 11010 - same // (x * 0x0d) >> 7: 1101 - same, shortest code (on i386) d0 = 6*(d3 + d2 + d1) + (q & 0xf); q = (d0 * 0xcd) >> 11; d0 = d0 - 10*q; *buf++ = d0 + '0'; d1 = q + 9*d3 + 5*d2 + d1; q = (d1 * 0xcd) >> 11; d1 = d1 - 10*q; *buf++ = d1 + '0'; d2 = q + 2*d2; q = (d2 * 0xd) >> 7; d2 = d2 - 10*q; *buf++ = d2 + '0'; d3 = q + 4*d3; q = (d3 * 0xcd) >> 11; /* - shorter code */ /* q = (d3 * 0x67) >> 10; - would also work */ d3 = d3 - 10*q; *buf++ = d3 + '0'; *buf++ = q + '0'; return buf; } /* No inlining helps gcc to use registers better */ static noinline char* put_dec(char *buf, unsigned long long num) { while (1) { unsigned rem; if (num < 100000) return put_dec_trunc(buf, num); rem = do_div(num, 100000); buf = put_dec_full(buf, rem); } } #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 SMALL 32 /* Must be 32 == 0x20 */ #define SPECIAL 64 /* 0x */ static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type) { /* we are called with base 8, 10 or 16, only, thus don't need "G..." */ static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ char tmp[66]; char sign; char locase; int need_pfx = ((type & SPECIAL) && base != 10); int i; /* locase = 0 or 0x20. ORing digits or letters with 'locase' * produces same digits or (maybe lowercased) letters */ locase = (type & SMALL); if (type & LEFT) type &= ~ZEROPAD; 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 (need_pfx) { size--; if (base == 16) size--; } /* generate full string in tmp[], in reverse order */ i = 0; if (num == 0) tmp[i++] = '0'; /* Generic code, for any base: else do { tmp[i++] = (digits[do_div(num,base)] | locase); } while (num != 0); */ else if (base != 10) { /* 8 or 16 */ int mask = base - 1; int shift = 3; if (base == 16) shift = 4; do { tmp[i++] = (digits[((unsigned char)num) & mask] | locase); num >>= shift; } while (num); } else { /* base 10 */ i = put_dec(tmp, num) - tmp; } /* printing 100 using %2d gives "100", not "00" */ if (i > precision) precision = i; /* leading space padding */ size -= precision; if (!(type & (ZEROPAD+LEFT))) { while(--size >= 0) { if (buf < end) *buf = ' '; ++buf; } } /* sign */ if (sign) { if (buf < end) *buf = sign; ++buf; } /* "0x" / "0" prefix */ if (need_pfx) { if (buf < end) *buf = '0'; ++buf; if (base == 16) { if (buf < end) *buf = ('X' | locase); ++buf; } } /* zero or space padding */ if (!(type & LEFT)) { char c = (type & ZEROPAD) ? '0' : ' '; while (--size >= 0) { if (buf < end) *buf = c; ++buf; } } /* hmm even more zero padding? */ while (i <= --precision) { if (buf < end) *buf = '0'; ++buf; } /* actual digits of result */ while (--i >= 0) { if (buf < end) *buf = tmp[i]; ++buf; } /* trailing space padding */ while (--size >= 0) { if (buf < end) *buf = ' '; ++buf; } return buf; } static char *string(char *buf, char *end, char *s, int field_width, int precision, int flags) { int len, i; if ((unsigned long)s < PAGE_SIZE) s = "<NULL>"; len = strnlen(s, precision); if (!(flags & LEFT)) { while (len < field_width--) { if (buf < end) *buf = ' '; ++buf; } } for (i = 0; i < len; ++i) { if (buf < end) *buf = *s; ++buf; ++s; } while (len < field_width--) { if (buf < end) *buf = ' '; ++buf; } return buf; } static char *symbol_string(char *buf, char *end, void *ptr, int field_width, int precision, int flags) { unsigned long value = (unsigned long) ptr; #ifdef CONFIG_KALLSYMS char sym[KSYM_SYMBOL_LEN]; sprint_symbol(sym, value); return string(buf, end, sym, field_width, precision, flags); #else field_width = 2*sizeof(void *); flags |= SPECIAL | SMALL | ZEROPAD; return number(buf, end, value, 16, field_width, precision, flags); #endif } static char *resource_string(char *buf, char *end, struct resource *res, int field_width, int precision, int flags) { #ifndef IO_RSRC_PRINTK_SIZE #define IO_RSRC_PRINTK_SIZE 4 #endif #ifndef MEM_RSRC_PRINTK_SIZE #define MEM_RSRC_PRINTK_SIZE 8 #endif /* room for the actual numbers, the two "0x", -, [, ] and the final zero */ char sym[4*sizeof(resource_size_t) + 8]; char *p = sym, *pend = sym + sizeof(sym); int size = -1; if (res->flags & IORESOURCE_IO) size = IO_RSRC_PRINTK_SIZE; else if (res->flags & IORESOURCE_MEM) size = MEM_RSRC_PRINTK_SIZE; *p++ = '['; p = number(p, pend, res->start, 16, size, -1, SPECIAL | SMALL | ZEROPAD); *p++ = '-'; p = number(p, pend, res->end, 16, size, -1, SPECIAL | SMALL | ZEROPAD); *p++ = ']'; *p = 0; return string(buf, end, sym, field_width, precision, flags); } static char *mac_address_string(char *buf, char *end, u8 *addr, int field_width, int precision, int flags) { char mac_addr[6 * 3]; /* (6 * 2 hex digits), 5 colons and trailing zero */ char *p = mac_addr; int i; for (i = 0; i < 6; i++) { p = pack_hex_byte(p, addr[i]); if (!(flags & SPECIAL) && i != 5) *p++ = ':'; } *p = '\0'; return string(buf, end, mac_addr, field_width, precision, flags & ~SPECIAL); } static char *ip6_addr_string(char *buf, char *end, u8 *addr, int field_width, int precision, int flags) { char ip6_addr[8 * 5]; /* (8 * 4 hex digits), 7 colons and trailing zero */ char *p = ip6_addr; int i; for (i = 0; i < 8; i++) { p = pack_hex_byte(p, addr[2 * i]); p = pack_hex_byte(p, addr[2 * i + 1]); if (!(flags & SPECIAL) && i != 7) *p++ = ':'; } *p = '\0'; return string(buf, end, ip6_addr, field_width, precision, flags & ~SPECIAL); } static char *ip4_addr_string(char *buf, char *end, u8 *addr, int field_width, int precision, int flags) { char ip4_addr[4 * 4]; /* (4 * 3 decimal digits), 3 dots and trailing zero */ char temp[3]; /* hold each IP quad in reverse order */ char *p = ip4_addr; int i, digits; for (i = 0; i < 4; i++) { digits = put_dec_trunc(temp, addr[i]) - temp; /* reverse the digits in the quad */ while (digits--) *p++ = temp[digits]; if (i != 3) *p++ = '.'; } *p = '\0'; return string(buf, end, ip4_addr, field_width, precision, flags & ~SPECIAL); } /* * Show a '%p' thing. A kernel extension is that the '%p' is followed * by an extra set of alphanumeric characters that are extended format * specifiers. * * Right now we handle: * * - 'F' For symbolic function descriptor pointers * - 'S' For symbolic direct pointers * - 'R' For a struct resource pointer, it prints the range of * addresses (not the name nor the flags) * - 'M' For a 6-byte MAC address, it prints the address in the * usual colon-separated hex notation * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way (dot-separated * decimal for v4 and colon separated network-order 16 bit hex for v6) * - 'i' [46] for 'raw' IPv4/IPv6 addresses, IPv6 omits the colons, IPv4 is * currently the same * * Note: The difference between 'S' and 'F' is that on ia64 and ppc64 * function pointers are really function descriptors, which contain a * pointer to the real address. */ static char *pointer(const char *fmt, char *buf, char *end, void *ptr, int field_width, int precision, int flags) { if (!ptr) return string(buf, end, "(null)", field_width, precision, flags); switch (*fmt) { case 'F': ptr = dereference_function_descriptor(ptr); /* Fallthrough */ case 'S': return symbol_string(buf, end, ptr, field_width, precision, flags); case 'R': return resource_string(buf, end, ptr, field_width, precision, flags); case 'm': flags |= SPECIAL; /* Fallthrough */ case 'M': return mac_address_string(buf, end, ptr, field_width, precision, flags); case 'i': flags |= SPECIAL; /* Fallthrough */ case 'I': if (fmt[1] == '6') return ip6_addr_string(buf, end, ptr, field_width, precision, flags); if (fmt[1] == '4') return ip4_addr_string(buf, end, ptr, field_width, precision, flags); flags &= ~SPECIAL; break; } flags |= SMALL; if (field_width == -1) { field_width = 2*sizeof(void *); flags |= ZEROPAD; } return number(buf, end, (unsigned long) ptr, 16, field_width, precision, flags); } /** * 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 * * This function follows C99 vsnprintf, but has some extensions: * %pS output the name of a text symbol * %pF output the name of a function pointer * %pR output the address range in a struct resource * * 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) { unsigned long long num; int base; char *str, *end, c; 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 */ /* 't' added for ptrdiff_t */ /* Reject out-of-range values early. Large positive sizes are used for unknown buffer sizes. */ if (unlikely((int) size < 0)) { /* There can be only one.. */ static char warn = 1; WARN_ON(warn); warn = 0; return 0; } str = buf; end = buf + size; /* Make sure end is always >= buf */ if (end < buf) { end = ((void *)-1); size = end - buf; } 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' || *fmt == 't') { 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) { if (str < end) *str = ' '; ++str; } } c = (unsigned char) va_arg(args, int); if (str < end) *str = c; ++str; while (--field_width > 0) { if (str < end) *str = ' '; ++str; } continue; case 's': str = string(str, end, va_arg(args, char *), field_width, precision, flags); continue; case 'p': str = pointer(fmt+1, str, end, va_arg(args, void *), field_width, precision, flags); /* Skip all alphanumeric pointer suffixes */ while (isalnum(fmt[1])) fmt++; continue; case 'n': /* FIXME: * What does C99 say about the overflow case here? */ if (qualifier == 'l') { long * ip = va_arg(args, long *); *ip = (str - buf); } else if (qualifier == 'Z' || qualifier == 'z') { size_t * ip = va_arg(args, size_t *); *ip = (str - buf); } else { int * ip = va_arg(args, int *); *ip = (str - buf); } continue; case '%': if (str < end) *str = '%'; ++str; continue; /* integer number formats - set up the flags and "break" */ case 'o': base = 8; break; case 'x': flags |= SMALL; case 'X': base = 16; break; case 'd': case 'i': flags |= SIGN; case 'u': break; default: if (str < end) *str = '%'; ++str; if (*fmt) { if (str < end) *str = *fmt; ++str; } else { --fmt; } continue; } if (qualifier == 'L') num = va_arg(args, long long); else if (qualifier == 'l') { num = va_arg(args, unsigned long); if (flags & SIGN) num = (signed long) num; } else if (qualifier == 'Z' || qualifier == 'z') { num = va_arg(args, size_t); } else if (qualifier == 't') { num = va_arg(args, ptrdiff_t); } else if (qualifier == 'h') { num = (unsigned short) va_arg(args, int); if (flags & SIGN) num = (signed short) num; } else { num = va_arg(args, unsigned int); if (flags & SIGN) num = (signed int) num; } str = number(str, end, num, base, field_width, precision, flags); } if (size > 0) { if (str < end) *str = '\0'; else end[-1] = '\0'; } /* the trailing null byte doesn't count towards the total */ return str-buf; } EXPORT_SYMBOL(vsnprintf); /** * vscnprintf - 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 have been written into * the @buf not including the trailing '\0'. If @size is <= 0 the function * returns 0. * * Call this function if you are already dealing with a va_list. * You probably want scnprintf() instead. * * See the vsnprintf() documentation for format string extensions over C99. */ int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) { int i; i=vsnprintf(buf,size,fmt,args); return (i >= size) ? (size - 1) : i; } EXPORT_SYMBOL(vscnprintf); /** * snprintf - 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 * @...: Arguments for the format string * * The return value is the number of characters which would be * generated for the given input, excluding the trailing null, * as per ISO C99. If the return is greater than or equal to * @size, the resulting string is truncated. * * See the vsnprintf() documentation for format string extensions over C99. */ int snprintf(char * buf, size_t size, const char *fmt, ...) { va_list args; int i; va_start(args, fmt); i=vsnprintf(buf,size,fmt,args); va_end(args); return i; } EXPORT_SYMBOL(snprintf); /** * scnprintf - 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 * @...: Arguments for the format string * * The return value is the number of characters written into @buf not including * the trailing '\0'. If @size is <= 0 the function returns 0. */ int scnprintf(char * buf, size_t size, const char *fmt, ...) { va_list args; int i; va_start(args, fmt); i = vsnprintf(buf, size, fmt, args); va_end(args); return (i >= size) ? (size - 1) : i; } EXPORT_SYMBOL(scnprintf); /** * vsprintf - Format a string and place it in a buffer * @buf: The buffer to place the result into * @fmt: The format string to use * @args: Arguments for the format string * * The function returns the number of characters written * into @buf. Use vsnprintf() or vscnprintf() in order to avoid * buffer overflows. * * Call this function if you are already dealing with a va_list. * You probably want sprintf() instead. * * See the vsnprintf() documentation for format string extensions over C99. */ int vsprintf(char *buf, const char *fmt, va_list args) { return vsnprintf(buf, INT_MAX, fmt, args); } EXPORT_SYMBOL(vsprintf); /** * sprintf - Format a string and place it in a buffer * @buf: The buffer to place the result into * @fmt: The format string to use * @...: Arguments for the format string * * The function returns the number of characters written * into @buf. Use snprintf() or scnprintf() in order to avoid * buffer overflows. * * See the vsnprintf() documentation for format string extensions over C99. */ int sprintf(char * buf, const char *fmt, ...) { va_list args; int i; va_start(args, fmt); i=vsnprintf(buf, INT_MAX, fmt, args); va_end(args); return i; } EXPORT_SYMBOL(sprintf); /** * vsscanf - Unformat a buffer into a list of arguments * @buf: input buffer * @fmt: format of buffer * @args: arguments */ int vsscanf(const char * buf, const char * fmt, va_list args) { const char *str = buf; char *next; char digit; int num = 0; int qualifier; int base; int field_width; int is_sign = 0; while(*fmt && *str) { /* skip any white space in format */ /* white space in format matchs any amount of * white space, including none, in the input. */ if (isspace(*fmt)) { while (isspace(*fmt)) ++fmt; while (isspace(*str)) ++str; } /* anything that is not a conversion must match exactly */ if (*fmt != '%' && *fmt) { if (*fmt++ != *str++) break; continue; } if (!*fmt) break; ++fmt; /* skip this conversion. * advance both strings to next white space */ if (*fmt == '*') { while (!isspace(*fmt) && *fmt) fmt++; while (!isspace(*str) && *str) str++; continue; } /* get field width */ field_width = -1; if (isdigit(*fmt)) field_width = skip_atoi(&fmt); /* get conversion qualifier */ qualifier = -1; if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || *fmt == 'Z' || *fmt == 'z') { qualifier = *fmt++; if (unlikely(qualifier == *fmt)) { if (qualifier == 'h') { qualifier = 'H'; fmt++; } else if (qualifier == 'l') { qualifier = 'L'; fmt++; } } } base = 10; is_sign = 0; if (!*fmt || !*str) break; switch(*fmt++) { case 'c': { char *s = (char *) va_arg(args,char*); if (field_width == -1) field_width = 1; do { *s++ = *str++; } while (--field_width > 0 && *str); num++; } continue; case 's': { char *s = (char *) va_arg(args, char *); if(field_width == -1) field_width = INT_MAX; /* first, skip leading white space in buffer */ while (isspace(*str)) str++; /* now copy until next white space */ while (*str && !isspace(*str) && field_width--) { *s++ = *str++; } *s = '\0'; num++; } continue; case 'n': /* return number of characters read so far */ { int *i = (int *)va_arg(args,int*); *i = str - buf; } continue; case 'o': base = 8; break; case 'x': case 'X': base = 16; break; case 'i': base = 0; case 'd': is_sign = 1; case 'u': break; case '%': /* looking for '%' in str */ if (*str++ != '%') return num; continue; default: /* invalid format; stop here */ return num; } /* have some sort of integer conversion. * first, skip white space in buffer. */ while (isspace(*str)) str++; digit = *str; if (is_sign && digit == '-') digit = *(str + 1); if (!digit || (base == 16 && !isxdigit(digit)) || (base == 10 && !isdigit(digit)) || (base == 8 && (!isdigit(digit) || digit > '7')) || (base == 0 && !isdigit(digit))) break; switch(qualifier) { case 'H': /* that's 'hh' in format */ if (is_sign) { signed char *s = (signed char *) va_arg(args,signed char *); *s = (signed char) simple_strtol(str,&next,base); } else { unsigned char *s = (unsigned char *) va_arg(args, unsigned char *); *s = (unsigned char) simple_strtoul(str, &next, base); } break; case 'h': if (is_sign) { short *s = (short *) va_arg(args,short *); *s = (short) simple_strtol(str,&next,base); } else { unsigned short *s = (unsigned short *) va_arg(args, unsigned short *); *s = (unsigned short) simple_strtoul(str, &next, base); } break; case 'l': if (is_sign) { long *l = (long *) va_arg(args,long *); *l = simple_strtol(str,&next,base); } else { unsigned long *l = (unsigned long*) va_arg(args,unsigned long*); *l = simple_strtoul(str,&next,base); } break; case 'L': if (is_sign) { long long *l = (long long*) va_arg(args,long long *); *l = simple_strtoll(str,&next,base); } else { unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*); *l = simple_strtoull(str,&next,base); } break; case 'Z': case 'z': { size_t *s = (size_t*) va_arg(args,size_t*); *s = (size_t) simple_strtoul(str,&next,base); } break; default: if (is_sign) { int *i = (int *) va_arg(args, int*); *i = (int) simple_strtol(str,&next,base); } else { unsigned int *i = (unsigned int*) va_arg(args, unsigned int*); *i = (unsigned int) simple_strtoul(str,&next,base); } break; } num++; if (!next) break; str = next; } /* * Now we've come all the way through so either the input string or the * format ended. In the former case, there can be a %n at the current * position in the format that needs to be filled. */ if (*fmt == '%' && *(fmt + 1) == 'n') { int *p = (int *)va_arg(args, int *); *p = str - buf; } return num; } EXPORT_SYMBOL(vsscanf); /** * sscanf - Unformat a buffer into a list of arguments * @buf: input buffer * @fmt: formatting of buffer * @...: resulting arguments */ int sscanf(const char * buf, const char * fmt, ...) { va_list args; int i; va_start(args,fmt); i = vsscanf(buf,fmt,args); va_end(args); return i; } EXPORT_SYMBOL(sscanf);