string.cpp

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/* $Id: string.cpp 14557 2008-11-02 11:41:13Z skidd13 $ */

#include "stdafx.h"
#include "openttd.h"
#include "debug.h"
#include "core/alloc_func.hpp"
#include "core/math_func.hpp"
#include "string_func.h"

#include "table/control_codes.h"

#include <stdarg.h>
#include <ctype.h> // required for tolower()

static int CDECL vseprintf(char *str, const char *last, const char *format, va_list ap)
{
  if (str >= last) return 0;
  size_t size = last - str;
  return min((int)size, vsnprintf(str, size, format, ap));
}

void ttd_strlcat(char *dst, const char *src, size_t size)
{
  assert(size > 0);
  while (size > 0 && *dst != '\0') {
    size--;
    dst++;
  }

  ttd_strlcpy(dst, src, size);
}


void ttd_strlcpy(char *dst, const char *src, size_t size)
{
  assert(size > 0);
  while (--size > 0 && *src != '\0') {
    *dst++ = *src++;
  }
  *dst = '\0';
}


char* strecat(char* dst, const char* src, const char* last)
{
  assert(dst <= last);
  while (*dst != '\0') {
    if (dst == last) return dst;
    dst++;
  }

  return strecpy(dst, src, last);
}


char* strecpy(char* dst, const char* src, const char* last)
{
  assert(dst <= last);
  while (dst != last && *src != '\0') {
    *dst++ = *src++;
  }
  *dst = '\0';

  if (dst == last && *src != '\0') {
#ifdef STRGEN
    error("String too long for destination buffer");
#else /* STRGEN */
    DEBUG(misc, 0, "String too long for destination buffer");
#endif /* STRGEN */
  }
  return dst;
}


char *CDECL str_fmt(const char *str, ...)
{
  char buf[4096];
  va_list va;

  va_start(va, str);
  int len = vseprintf(buf, lastof(buf), str, va);
  va_end(va);
  char *p = MallocT<char>(len + 1);
  memcpy(p, buf, len + 1);
  return p;
}


void str_validate(char *str)
{
  char *dst = str;
  WChar c;
  size_t len;

  for (len = Utf8Decode(&c, str); c != '\0'; len = Utf8Decode(&c, str)) {
    if (IsPrintable(c) && (c < SCC_SPRITE_START || c > SCC_SPRITE_END ||
      IsValidChar(c - SCC_SPRITE_START, CS_ALPHANUMERAL))) {
      /* Copy the character back. Even if dst is current the same as str
       * (i.e. no characters have been changed) this is quicker than
       * moving the pointers ahead by len */
      do {
        *dst++ = *str++;
      } while (--len != 0);
    } else {
      /* Replace the undesirable character with a question mark */
      str += len;
      *dst++ = '?';
    }
  }

  *dst = '\0';
}


void str_strip_colours(char *str)
{
  char *dst = str;
  WChar c;
  size_t len;

  for (len = Utf8Decode(&c, str); c != '\0'; len = Utf8Decode(&c, str)) {
    if (c < SCC_BLUE || c > SCC_BLACK) {
      /* Copy the character back. Even if dst is current the same as str
       * (i.e. no characters have been changed) this is quicker than
       * moving the pointers ahead by len */
      do {
        *dst++ = *str++;
      } while (--len != 0);
    } else {
      /* Just skip (strip) the colour codes */
      str += len;
    }
  }
  *dst = '\0';
}

void strtolower(char *str)
{
  for (; *str != '\0'; str++) *str = tolower(*str);
}

bool IsValidChar(WChar key, CharSetFilter afilter)
{
  switch (afilter) {
    case CS_ALPHANUMERAL: return IsPrintable(key);
    case CS_NUMERAL:      return (key >= '0' && key <= '9');
    case CS_ALPHA:        return IsPrintable(key) && !(key >= '0' && key <= '9');
  }

  return false;
}

#ifdef WIN32
/* Since version 3.14, MinGW Runtime has snprintf() and vsnprintf() conform to C99 but it's not the case for older versions */
#if (__MINGW32_MAJOR_VERSION < 3) || ((__MINGW32_MAJOR_VERSION == 3) && (__MINGW32_MINOR_VERSION < 14))
int CDECL snprintf(char *str, size_t size, const char *format, ...)
{
  va_list ap;
  int ret;

  va_start(ap, format);
  ret = vsnprintf(str, size, format, ap);
  va_end(ap);
  return ret;
}
#endif /* MinGW Runtime < 3.14 */

#ifdef _MSC_VER
/* *nprintf broken, not POSIX compliant, MSDN description
 * - If len < count, then len characters are stored in buffer, a null-terminator is appended, and len is returned.
 * - If len = count, then len characters are stored in buffer, no null-terminator is appended, and len is returned.
 * - If len > count, then count characters are stored in buffer, no null-terminator is appended, and a negative value is returned
 */
int CDECL vsnprintf(char *str, size_t size, const char *format, va_list ap)
{
  int ret;
  ret = _vsnprintf(str, size, format, ap);
  if (ret < 0 || ret == size) str[size - 1] = '\0';
  return ret;
}
#endif /* _MSC_VER */

#endif /* WIN32 */

int CDECL seprintf(char *str, const char *last, const char *format, ...)
{
  va_list ap;

  va_start(ap, format);
  int ret = vseprintf(str, last, format, ap);
  va_end(ap);
  return ret;
}


char *md5sumToString(char *buf, const char *last, const uint8 md5sum[16])
{
  char *p = buf;

  for (uint i = 0; i < 16; i++) {
    p += seprintf(p, last, "%02X", md5sum[i]);
  }

  return p;
}


/* UTF-8 handling routines */


/* Decode and consume the next UTF-8 encoded character
 * @param c Buffer to place decoded character.
 * @param s Character stream to retrieve character from.
 * @return Number of characters in the sequence.
 */
size_t Utf8Decode(WChar *c, const char *s)
{
  assert(c != NULL);

  if (!HasBit(s[0], 7)) {
    /* Single byte character: 0xxxxxxx */
    *c = s[0];
    return 1;
  } else if (GB(s[0], 5, 3) == 6) {
    if (IsUtf8Part(s[1])) {
      /* Double byte character: 110xxxxx 10xxxxxx */
      *c = GB(s[0], 0, 5) << 6 | GB(s[1], 0, 6);
      if (*c >= 0x80) return 2;
    }
  } else if (GB(s[0], 4, 4) == 14) {
    if (IsUtf8Part(s[1]) && IsUtf8Part(s[2])) {
      /* Triple byte character: 1110xxxx 10xxxxxx 10xxxxxx */
      *c = GB(s[0], 0, 4) << 12 | GB(s[1], 0, 6) << 6 | GB(s[2], 0, 6);
      if (*c >= 0x800) return 3;
    }
  } else if (GB(s[0], 3, 5) == 30) {
    if (IsUtf8Part(s[1]) && IsUtf8Part(s[2]) && IsUtf8Part(s[3])) {
      /* 4 byte character: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
      *c = GB(s[0], 0, 3) << 18 | GB(s[1], 0, 6) << 12 | GB(s[2], 0, 6) << 6 | GB(s[3], 0, 6);
      if (*c >= 0x10000 && *c <= 0x10FFFF) return 4;
    }
  }

  //DEBUG(misc, 1, "[utf8] invalid UTF-8 sequence");
  *c = '?';
  return 1;
}


/* Encode a unicode character and place it in the buffer
 * @param buf Buffer to place character.
 * @param c   Unicode character to encode.
 * @return Number of characters in the encoded sequence.
 */
size_t Utf8Encode(char *buf, WChar c)
{
  if (c < 0x80) {
    *buf = c;
    return 1;
  } else if (c < 0x800) {
    *buf++ = 0xC0 + GB(c,  6, 5);
    *buf   = 0x80 + GB(c,  0, 6);
    return 2;
  } else if (c < 0x10000) {
    *buf++ = 0xE0 + GB(c, 12, 4);
    *buf++ = 0x80 + GB(c,  6, 6);
    *buf   = 0x80 + GB(c,  0, 6);
    return 3;
  } else if (c < 0x110000) {
    *buf++ = 0xF0 + GB(c, 18, 3);
    *buf++ = 0x80 + GB(c, 12, 6);
    *buf++ = 0x80 + GB(c,  6, 6);
    *buf   = 0x80 + GB(c,  0, 6);
    return 4;
  }

  //DEBUG(misc, 1, "[utf8] can't UTF-8 encode value 0x%X", c);
  *buf = '?';
  return 1;
}

size_t Utf8TrimString(char *s, size_t maxlen)
{
  size_t length = 0;

  for (const char *ptr = strchr(s, '\0'); *s != '\0';) {
    size_t len = Utf8EncodedCharLen(*s);
    /* Silently ignore invalid UTF8 sequences, our only concern trimming */
    if (len == 0) len = 1;

    /* Take care when a hard cutoff was made for the string and
     * the last UTF8 sequence is invalid */
    if (length + len >= maxlen || (s + len > ptr)) break;
    s += len;
    length += len;
  }

  *s = '\0';
  return length;
}

#ifndef _GNU_SOURCE
#include "core/math_func.hpp"
char *strndup(const char *s, size_t len)
{
  len = min(strlen(s), len);
  char *tmp = CallocT<char>(len + 1);
  memcpy(tmp, s, len);
  return tmp;
}
#endif /* !_GNU_SOURCE */