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  1. /*
  2.  * Copyright (c) 2005 Martin Decky
  3.  * Copyright (c) 2008 Jiri Svoboda
  4.  * All rights reserved.
  5.  *
  6.  * Redistribution and use in source and binary forms, with or without
  7.  * modification, are permitted provided that the following conditions
  8.  * are met:
  9.  *
  10.  * - Redistributions of source code must retain the above copyright
  11.  *   notice, this list of conditions and the following disclaimer.
  12.  * - Redistributions in binary form must reproduce the above copyright
  13.  *   notice, this list of conditions and the following disclaimer in the
  14.  *   documentation and/or other materials provided with the distribution.
  15.  * - The name of the author may not be used to endorse or promote products
  16.  *   derived from this software without specific prior written permission.
  17.  *
  18.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28.  */
  29.  
  30. /** @addtogroup libc
  31.  * @{
  32.  */
  33. /** @file
  34.  */
  35.  
  36. #include <string.h>
  37. #include <stdlib.h>
  38. #include <limits.h>
  39. #include <ctype.h>
  40. #include <malloc.h>
  41. #include <errno.h>
  42. #include <align.h>
  43. #include <string.h>
  44.  
  45. /** Byte mask consisting of lowest @n bits (out of 8) */
  46. #define LO_MASK_8(n)  ((uint8_t) ((1 << (n)) - 1))
  47.  
  48. /** Byte mask consisting of lowest @n bits (out of 32) */
  49. #define LO_MASK_32(n)  ((uint32_t) ((1 << (n)) - 1))
  50.  
  51. /** Byte mask consisting of highest @n bits (out of 8) */
  52. #define HI_MASK_8(n)  (~LO_MASK_8(8 - (n)))
  53.  
  54. /** Number of data bits in a UTF-8 continuation byte */
  55. #define CONT_BITS  6
  56.  
  57. /** Decode a single character from a string.
  58.  *
  59.  * Decode a single character from a string of size @a size. Decoding starts
  60.  * at @a offset and this offset is moved to the beginning of the next
  61.  * character. In case of decoding error, offset generally advances at least
  62.  * by one. However, offset is never moved beyond size.
  63.  *
  64.  * @param str    String (not necessarily NULL-terminated).
  65.  * @param offset Byte offset in string where to start decoding.
  66.  * @param size   Size of the string (in bytes).
  67.  *
  68.  * @return Value of decoded character, U_SPECIAL on decoding error or
  69.  *         NULL if attempt to decode beyond @a size.
  70.  *
  71.  */
  72. wchar_t str_decode(const char *str, size_t *offset, size_t size)
  73. {
  74.     if (*offset + 1 > size)
  75.         return 0;
  76.    
  77.     /* First byte read from string */
  78.     uint8_t b0 = (uint8_t) str[(*offset)++];
  79.    
  80.     /* Determine code length */
  81.    
  82.     unsigned int b0_bits;  /* Data bits in first byte */
  83.     unsigned int cbytes;   /* Number of continuation bytes */
  84.    
  85.     if ((b0 & 0x80) == 0) {
  86.         /* 0xxxxxxx (Plain ASCII) */
  87.         b0_bits = 7;
  88.         cbytes = 0;
  89.     } else if ((b0 & 0xe0) == 0xc0) {
  90.         /* 110xxxxx 10xxxxxx */
  91.         b0_bits = 5;
  92.         cbytes = 1;
  93.     } else if ((b0 & 0xf0) == 0xe0) {
  94.         /* 1110xxxx 10xxxxxx 10xxxxxx */
  95.         b0_bits = 4;
  96.         cbytes = 2;
  97.     } else if ((b0 & 0xf8) == 0xf0) {
  98.         /* 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
  99.         b0_bits = 3;
  100.         cbytes = 3;
  101.     } else {
  102.         /* 10xxxxxx -- unexpected continuation byte */
  103.         return U_SPECIAL;
  104.     }
  105.    
  106.     if (*offset + cbytes > size)
  107.         return U_SPECIAL;
  108.    
  109.     wchar_t ch = b0 & LO_MASK_8(b0_bits);
  110.    
  111.     /* Decode continuation bytes */
  112.     while (cbytes > 0) {
  113.         uint8_t b = (uint8_t) str[(*offset)++];
  114.        
  115.         /* Must be 10xxxxxx */
  116.         if ((b & 0xc0) != 0x80)
  117.             return U_SPECIAL;
  118.        
  119.         /* Shift data bits to ch */
  120.         ch = (ch << CONT_BITS) | (wchar_t) (b & LO_MASK_8(CONT_BITS));
  121.         cbytes--;
  122.     }
  123.    
  124.     return ch;
  125. }
  126.  
  127. /** Encode a single character to string representation.
  128.  *
  129.  * Encode a single character to string representation (i.e. UTF-8) and store
  130.  * it into a buffer at @a offset. Encoding starts at @a offset and this offset
  131.  * is moved to the position where the next character can be written to.
  132.  *
  133.  * @param ch     Input character.
  134.  * @param str    Output buffer.
  135.  * @param offset Byte offset where to start writing.
  136.  * @param size   Size of the output buffer (in bytes).
  137.  *
  138.  * @return EOK if the character was encoded successfully, EOVERFLOW if there
  139.  *     was not enough space in the output buffer or EINVAL if the character
  140.  *     code was invalid.
  141.  */
  142. int chr_encode(const wchar_t ch, char *str, size_t *offset, size_t size)
  143. {
  144.     if (*offset >= size)
  145.         return EOVERFLOW;
  146.    
  147.     if (!chr_check(ch))
  148.         return EINVAL;
  149.    
  150.     /* Unsigned version of ch (bit operations should only be done
  151.        on unsigned types). */
  152.     uint32_t cc = (uint32_t) ch;
  153.    
  154.     /* Determine how many continuation bytes are needed */
  155.    
  156.     unsigned int b0_bits;  /* Data bits in first byte */
  157.     unsigned int cbytes;   /* Number of continuation bytes */
  158.    
  159.     if ((cc & ~LO_MASK_32(7)) == 0) {
  160.         b0_bits = 7;
  161.         cbytes = 0;
  162.     } else if ((cc & ~LO_MASK_32(11)) == 0) {
  163.         b0_bits = 5;
  164.         cbytes = 1;
  165.     } else if ((cc & ~LO_MASK_32(16)) == 0) {
  166.         b0_bits = 4;
  167.         cbytes = 2;
  168.     } else if ((cc & ~LO_MASK_32(21)) == 0) {
  169.         b0_bits = 3;
  170.         cbytes = 3;
  171.     } else {
  172.         /* Codes longer than 21 bits are not supported */
  173.         return EINVAL;
  174.     }
  175.    
  176.     /* Check for available space in buffer */
  177.     if (*offset + cbytes >= size)
  178.         return EOVERFLOW;
  179.    
  180.     /* Encode continuation bytes */
  181.     unsigned int i;
  182.     for (i = cbytes; i > 0; i--) {
  183.         str[*offset + i] = 0x80 | (cc & LO_MASK_32(CONT_BITS));
  184.         cc = cc >> CONT_BITS;
  185.     }
  186.    
  187.     /* Encode first byte */
  188.     str[*offset] = (cc & LO_MASK_32(b0_bits)) | HI_MASK_8(8 - b0_bits - 1);
  189.    
  190.     /* Advance offset */
  191.     *offset += cbytes + 1;
  192.    
  193.     return EOK;
  194. }
  195.  
  196. /** Get size of string.
  197.  *
  198.  * Get the number of bytes which are used by the string @a str (excluding the
  199.  * NULL-terminator).
  200.  *
  201.  * @param str String to consider.
  202.  *
  203.  * @return Number of bytes used by the string
  204.  *
  205.  */
  206. size_t str_size(const char *str)
  207. {
  208.     size_t size = 0;
  209.    
  210.     while (*str++ != 0)
  211.         size++;
  212.    
  213.     return size;
  214. }
  215.  
  216. /** Get size of wide string.
  217.  *
  218.  * Get the number of bytes which are used by the wide string @a str (excluding the
  219.  * NULL-terminator).
  220.  *
  221.  * @param str Wide string to consider.
  222.  *
  223.  * @return Number of bytes used by the wide string
  224.  *
  225.  */
  226. size_t wstr_size(const wchar_t *str)
  227. {
  228.     return (wstr_length(str) * sizeof(wchar_t));
  229. }
  230.  
  231. /** Get size of string with length limit.
  232.  *
  233.  * Get the number of bytes which are used by up to @a max_len first
  234.  * characters in the string @a str. If @a max_len is greater than
  235.  * the length of @a str, the entire string is measured (excluding the
  236.  * NULL-terminator).
  237.  *
  238.  * @param str     String to consider.
  239.  * @param max_len Maximum number of characters to measure.
  240.  *
  241.  * @return Number of bytes used by the characters.
  242.  *
  243.  */
  244. size_t str_lsize(const char *str, count_t max_len)
  245. {
  246.     count_t len = 0;
  247.     size_t offset = 0;
  248.    
  249.     while (len < max_len) {
  250.         if (str_decode(str, &offset, STR_NO_LIMIT) == 0)
  251.             break;
  252.        
  253.         len++;
  254.     }
  255.    
  256.     return offset;
  257. }
  258.  
  259. /** Get size of wide string with length limit.
  260.  *
  261.  * Get the number of bytes which are used by up to @a max_len first
  262.  * wide characters in the wide string @a str. If @a max_len is greater than
  263.  * the length of @a str, the entire wide string is measured (excluding the
  264.  * NULL-terminator).
  265.  *
  266.  * @param str     Wide string to consider.
  267.  * @param max_len Maximum number of wide characters to measure.
  268.  *
  269.  * @return Number of bytes used by the wide characters.
  270.  *
  271.  */
  272. size_t wstr_lsize(const wchar_t *str, count_t max_len)
  273. {
  274.     return (wstr_nlength(str, max_len * sizeof(wchar_t)) * sizeof(wchar_t));
  275. }
  276.  
  277. /** Get number of characters in a string.
  278.  *
  279.  * @param str NULL-terminated string.
  280.  *
  281.  * @return Number of characters in string.
  282.  *
  283.  */
  284. count_t str_length(const char *str)
  285. {
  286.     count_t len = 0;
  287.     size_t offset = 0;
  288.    
  289.     while (str_decode(str, &offset, STR_NO_LIMIT) != 0)
  290.         len++;
  291.    
  292.     return len;
  293. }
  294.  
  295. /** Get number of characters in a wide string.
  296.  *
  297.  * @param str NULL-terminated wide string.
  298.  *
  299.  * @return Number of characters in @a str.
  300.  *
  301.  */
  302. count_t wstr_length(const wchar_t *wstr)
  303. {
  304.     count_t len = 0;
  305.    
  306.     while (*wstr++ != 0)
  307.         len++;
  308.    
  309.     return len;
  310. }
  311.  
  312. /** Get number of characters in a string with size limit.
  313.  *
  314.  * @param str  NULL-terminated string.
  315.  * @param size Maximum number of bytes to consider.
  316.  *
  317.  * @return Number of characters in string.
  318.  *
  319.  */
  320. count_t str_nlength(const char *str, size_t size)
  321. {
  322.     count_t len = 0;
  323.     size_t offset = 0;
  324.    
  325.     while (str_decode(str, &offset, size) != 0)
  326.         len++;
  327.    
  328.     return len;
  329. }
  330.  
  331. /** Get number of characters in a string with size limit.
  332.  *
  333.  * @param str  NULL-terminated string.
  334.  * @param size Maximum number of bytes to consider.
  335.  *
  336.  * @return Number of characters in string.
  337.  *
  338.  */
  339. count_t wstr_nlength(const wchar_t *str, size_t size)
  340. {
  341.     count_t len = 0;
  342.     count_t limit = ALIGN_DOWN(size, sizeof(wchar_t));
  343.     count_t offset = 0;
  344.    
  345.     while ((offset < limit) && (*str++ != 0)) {
  346.         len++;
  347.         offset += sizeof(wchar_t);
  348.     }
  349.    
  350.     return len;
  351. }
  352.  
  353. /** Check whether character is plain ASCII.
  354.  *
  355.  * @return True if character is plain ASCII.
  356.  *
  357.  */
  358. bool ascii_check(wchar_t ch)
  359. {
  360.     if ((ch >= 0) && (ch <= 127))
  361.         return true;
  362.    
  363.     return false;
  364. }
  365.  
  366. /** Check whether character is valid
  367.  *
  368.  * @return True if character is a valid Unicode code point.
  369.  *
  370.  */
  371. bool chr_check(wchar_t ch)
  372. {
  373.     if ((ch >= 0) && (ch <= 1114111))
  374.         return true;
  375.    
  376.     return false;
  377. }
  378.  
  379. /** Compare two NULL terminated strings.
  380.  *
  381.  * Do a char-by-char comparison of two NULL-terminated strings.
  382.  * The strings are considered equal iff they consist of the same
  383.  * characters on the minimum of their lengths.
  384.  *
  385.  * @param s1 First string to compare.
  386.  * @param s2 Second string to compare.
  387.  *
  388.  * @return 0 if the strings are equal, -1 if first is smaller,
  389.  *         1 if second smaller.
  390.  *
  391.  */
  392. int str_cmp(const char *s1, const char *s2)
  393. {
  394.     wchar_t c1 = 0;
  395.     wchar_t c2 = 0;
  396.    
  397.     size_t off1 = 0;
  398.     size_t off2 = 0;
  399.  
  400.     while (true) {
  401.         c1 = str_decode(s1, &off1, STR_NO_LIMIT);
  402.         c2 = str_decode(s2, &off2, STR_NO_LIMIT);
  403.  
  404.         if (c1 < c2)
  405.             return -1;
  406.        
  407.         if (c1 > c2)
  408.             return 1;
  409.  
  410.         if (c1 == 0 || c2 == 0)
  411.             break;     
  412.     }
  413.  
  414.     return 0;
  415. }
  416.  
  417. /** Compare two NULL terminated strings with length limit.
  418.  *
  419.  * Do a char-by-char comparison of two NULL-terminated strings.
  420.  * The strings are considered equal iff they consist of the same
  421.  * characters on the minimum of their lengths and the length limit.
  422.  *
  423.  * @param s1      First string to compare.
  424.  * @param s2      Second string to compare.
  425.  * @param max_len Maximum number of characters to consider.
  426.  *
  427.  * @return 0 if the strings are equal, -1 if first is smaller,
  428.  *         1 if second smaller.
  429.  *
  430.  */
  431. int str_lcmp(const char *s1, const char *s2, count_t max_len)
  432. {
  433.     wchar_t c1 = 0;
  434.     wchar_t c2 = 0;
  435.    
  436.     size_t off1 = 0;
  437.     size_t off2 = 0;
  438.    
  439.     count_t len = 0;
  440.  
  441.     while (true) {
  442.         if (len >= max_len)
  443.             break;
  444.  
  445.         c1 = str_decode(s1, &off1, STR_NO_LIMIT);
  446.         c2 = str_decode(s2, &off2, STR_NO_LIMIT);
  447.  
  448.         if (c1 < c2)
  449.             return -1;
  450.  
  451.         if (c1 > c2)
  452.             return 1;
  453.  
  454.         if (c1 == 0 || c2 == 0)
  455.             break;
  456.  
  457.         ++len; 
  458.     }
  459.  
  460.     return 0;
  461.  
  462. }
  463.  
  464. /** Copy NULL-terminated string.
  465.  *
  466.  * Copy source string @a src to destination buffer @a dst.
  467.  * No more than @a size bytes are written. NULL-terminator is always
  468.  * written after the last succesfully copied character (i.e. if the
  469.  * destination buffer is has at least 1 byte, it will be always
  470.  * NULL-terminated).
  471.  *
  472.  * @param src   Source string.
  473.  * @param dst   Destination buffer.
  474.  * @param count Size of the destination buffer.
  475.  *
  476.  */
  477. void str_ncpy(char *dst, const char *src, size_t size)
  478. {
  479.     /* No space for the NULL-terminator in the buffer */
  480.     if (size == 0)
  481.         return;
  482.    
  483.     wchar_t ch;
  484.     size_t str_off = 0;
  485.     size_t dst_off = 0;
  486.    
  487.     while ((ch = str_decode(src, &str_off, STR_NO_LIMIT)) != 0) {
  488.         if (chr_encode(ch, dst, &dst_off, size) != EOK)
  489.             break;
  490.     }
  491.    
  492.     if (dst_off >= size)
  493.         dst[size - 1] = 0;
  494.     else
  495.         dst[dst_off] = 0;
  496. }
  497.  
  498. /** Copy NULL-terminated wide string to string
  499.  *
  500.  * Copy source wide string @a src to destination buffer @a dst.
  501.  * No more than @a size bytes are written. NULL-terminator is always
  502.  * written after the last succesfully copied character (i.e. if the
  503.  * destination buffer is has at least 1 byte, it will be always
  504.  * NULL-terminated).
  505.  *
  506.  * @param src   Source wide string.
  507.  * @param dst   Destination buffer.
  508.  * @param count Size of the destination buffer.
  509.  *
  510.  */
  511. void wstr_nstr(char *dst, const wchar_t *src, size_t size)
  512. {
  513.     /* No space for the NULL-terminator in the buffer */
  514.     if (size == 0)
  515.         return;
  516.    
  517.     wchar_t ch;
  518.     count_t src_idx = 0;
  519.     size_t dst_off = 0;
  520.    
  521.     while ((ch = src[src_idx++]) != 0) {
  522.         if (chr_encode(ch, dst, &dst_off, size) != EOK)
  523.             break;
  524.     }
  525.    
  526.     if (dst_off >= size)
  527.         dst[size - 1] = 0;
  528.     else
  529.         dst[dst_off] = 0;
  530. }
  531.  
  532. /** Find first occurence of character in string.
  533.  *
  534.  * @param str String to search.
  535.  * @param ch  Character to look for.
  536.  *
  537.  * @return Pointer to character in @a str or NULL if not found.
  538.  *
  539.  */
  540. const char *str_chr(const char *str, wchar_t ch)
  541. {
  542.     wchar_t acc;
  543.     size_t off = 0;
  544.    
  545.     while ((acc = str_decode(str, &off, STR_NO_LIMIT)) != 0) {
  546.         if (acc == ch)
  547.             return (str + off);
  548.     }
  549.    
  550.     return NULL;
  551. }
  552.  
  553. /** Insert a wide character into a wide string.
  554.  *
  555.  * Insert a wide character into a wide string at position
  556.  * @a pos. The characters after the position are shifted.
  557.  *
  558.  * @param str     String to insert to.
  559.  * @param ch      Character to insert to.
  560.  * @param pos     Character index where to insert.
  561.  @ @param max_pos Characters in the buffer.
  562.  *
  563.  * @return True if the insertion was sucessful, false if the position
  564.  *         is out of bounds.
  565.  *
  566.  */
  567. bool wstr_linsert(wchar_t *str, wchar_t ch, count_t pos, count_t max_pos)
  568. {
  569.     count_t len = wstr_length(str);
  570.    
  571.     if ((pos > len) || (pos + 1 > max_pos))
  572.         return false;
  573.    
  574.     count_t i;
  575.     for (i = len; i + 1 > pos; i--)
  576.         str[i + 1] = str[i];
  577.    
  578.     str[pos] = ch;
  579.    
  580.     return true;
  581. }
  582.  
  583. /** Remove a wide character from a wide string.
  584.  *
  585.  * Remove a wide character from a wide string at position
  586.  * @a pos. The characters after the position are shifted.
  587.  *
  588.  * @param str String to remove from.
  589.  * @param pos Character index to remove.
  590.  *
  591.  * @return True if the removal was sucessful, false if the position
  592.  *         is out of bounds.
  593.  *
  594.  */
  595. bool wstr_remove(wchar_t *str, count_t pos)
  596. {
  597.     count_t len = wstr_length(str);
  598.    
  599.     if (pos >= len)
  600.         return false;
  601.    
  602.     count_t i;
  603.     for (i = pos + 1; i <= len; i++)
  604.         str[i - 1] = str[i];
  605.    
  606.     return true;
  607. }
  608.  
  609. int strncmp(const char *a, const char *b, size_t n)
  610. {
  611.     size_t c = 0;
  612.  
  613.     while (c < n && a[c] && b[c] && (!(a[c] - b[c])))
  614.         c++;
  615.    
  616.     return ( c < n ? a[c] - b[c] : 0);
  617.    
  618. }
  619.  
  620. int stricmp(const char *a, const char *b)
  621. {
  622.     int c = 0;
  623.    
  624.     while (a[c] && b[c] && (!(tolower(a[c]) - tolower(b[c]))))
  625.         c++;
  626.    
  627.     return (tolower(a[c]) - tolower(b[c]));
  628. }
  629.  
  630. /** Return pointer to the first occurence of character c in string.
  631.  *
  632.  * @param str       Scanned string.
  633.  * @param c     Searched character (taken as one byte).
  634.  * @return      Pointer to the matched character or NULL if it is not
  635.  *          found in given string.
  636.  */
  637. char *strchr(const char *str, int c)
  638. {
  639.     while (*str != '\0') {
  640.         if (*str == (char) c)
  641.             return (char *) str;
  642.         str++;
  643.     }
  644.  
  645.     return NULL;
  646. }
  647.  
  648. /** Return pointer to the last occurence of character c in string.
  649.  *
  650.  * @param str       Scanned string.
  651.  * @param c     Searched character (taken as one byte).
  652.  * @return      Pointer to the matched character or NULL if it is not
  653.  *          found in given string.
  654.  */
  655. char *strrchr(const char *str, int c)
  656. {
  657.     char *retval = NULL;
  658.  
  659.     while (*str != '\0') {
  660.         if (*str == (char) c)
  661.             retval = (char *) str;
  662.         str++;
  663.     }
  664.  
  665.     return (char *) retval;
  666. }
  667.  
  668. /** Convert string to a number.
  669.  * Core of strtol and strtoul functions.
  670.  *
  671.  * @param nptr      Pointer to string.
  672.  * @param endptr    If not NULL, function stores here pointer to the first
  673.  *          invalid character.
  674.  * @param base      Zero or number between 2 and 36 inclusive.
  675.  * @param sgn       It's set to 1 if minus found.
  676.  * @return      Result of conversion.
  677.  */
  678. static unsigned long
  679. _strtoul(const char *nptr, char **endptr, int base, char *sgn)
  680. {
  681.     unsigned char c;
  682.     unsigned long result = 0;
  683.     unsigned long a, b;
  684.     const char *str = nptr;
  685.     const char *tmpptr;
  686.    
  687.     while (isspace(*str))
  688.         str++;
  689.    
  690.     if (*str == '-') {
  691.         *sgn = 1;
  692.         ++str;
  693.     } else if (*str == '+')
  694.         ++str;
  695.    
  696.     if (base) {
  697.         if ((base == 1) || (base > 36)) {
  698.             /* FIXME: set errno to EINVAL */
  699.             return 0;
  700.         }
  701.         if ((base == 16) && (*str == '0') && ((str[1] == 'x') ||
  702.             (str[1] == 'X'))) {
  703.             str += 2;
  704.         }
  705.     } else {
  706.         base = 10;
  707.        
  708.         if (*str == '0') {
  709.             base = 8;
  710.             if ((str[1] == 'X') || (str[1] == 'x'))  {
  711.                 base = 16;
  712.                 str += 2;
  713.             }
  714.         }
  715.     }
  716.    
  717.     tmpptr = str;
  718.  
  719.     while (*str) {
  720.         c = *str;
  721.         c = (c >= 'a' ? c - 'a' + 10 : (c >= 'A' ? c - 'A' + 10 :
  722.             (c <= '9' ? c - '0' : 0xff)));
  723.         if (c > base) {
  724.             break;
  725.         }
  726.        
  727.         a = (result & 0xff) * base + c;
  728.         b = (result >> 8) * base + (a >> 8);
  729.        
  730.         if (b > (ULONG_MAX >> 8)) {
  731.             /* overflow */
  732.             /* FIXME: errno = ERANGE*/
  733.             return ULONG_MAX;
  734.         }
  735.    
  736.         result = (b << 8) + (a & 0xff);
  737.         ++str;
  738.     }
  739.    
  740.     if (str == tmpptr) {
  741.         /*
  742.          * No number was found => first invalid character is the first
  743.          * character of the string.
  744.          */
  745.         /* FIXME: set errno to EINVAL */
  746.         str = nptr;
  747.         result = 0;
  748.     }
  749.    
  750.     if (endptr)
  751.         *endptr = (char *) str;
  752.  
  753.     if (nptr == str) {
  754.         /*FIXME: errno = EINVAL*/
  755.         return 0;
  756.     }
  757.  
  758.     return result;
  759. }
  760.  
  761. /** Convert initial part of string to long int according to given base.
  762.  * The number may begin with an arbitrary number of whitespaces followed by
  763.  * optional sign (`+' or `-'). If the base is 0 or 16, the prefix `0x' may be
  764.  * inserted and the number will be taken as hexadecimal one. If the base is 0
  765.  * and the number begin with a zero, number will be taken as octal one (as with
  766.  * base 8). Otherwise the base 0 is taken as decimal.
  767.  *
  768.  * @param nptr      Pointer to string.
  769.  * @param endptr    If not NULL, function stores here pointer to the first
  770.  *          invalid character.
  771.  * @param base      Zero or number between 2 and 36 inclusive.
  772.  * @return      Result of conversion.
  773.  */
  774. long int strtol(const char *nptr, char **endptr, int base)
  775. {
  776.     char sgn = 0;
  777.     unsigned long number = 0;
  778.    
  779.     number = _strtoul(nptr, endptr, base, &sgn);
  780.  
  781.     if (number > LONG_MAX) {
  782.         if ((sgn) && (number == (unsigned long) (LONG_MAX) + 1)) {
  783.             /* FIXME: set 0 to errno */
  784.             return number;     
  785.         }
  786.         /* FIXME: set ERANGE to errno */
  787.         return (sgn ? LONG_MIN : LONG_MAX);
  788.     }
  789.    
  790.     return (sgn ? -number : number);
  791. }
  792.  
  793.  
  794. /** Convert initial part of string to unsigned long according to given base.
  795.  * The number may begin with an arbitrary number of whitespaces followed by
  796.  * optional sign (`+' or `-'). If the base is 0 or 16, the prefix `0x' may be
  797.  * inserted and the number will be taken as hexadecimal one. If the base is 0
  798.  * and the number begin with a zero, number will be taken as octal one (as with
  799.  * base 8). Otherwise the base 0 is taken as decimal.
  800.  *
  801.  * @param nptr      Pointer to string.
  802.  * @param endptr    If not NULL, function stores here pointer to the first
  803.  *          invalid character
  804.  * @param base      Zero or number between 2 and 36 inclusive.
  805.  * @return      Result of conversion.
  806.  */
  807. unsigned long strtoul(const char *nptr, char **endptr, int base)
  808. {
  809.     char sgn = 0;
  810.     unsigned long number = 0;
  811.    
  812.     number = _strtoul(nptr, endptr, base, &sgn);
  813.  
  814.     return (sgn ? -number : number);
  815. }
  816.  
  817. char *strcpy(char *dest, const char *src)
  818. {
  819.     char *orig = dest;
  820.    
  821.     while ((*(dest++) = *(src++)))
  822.         ;
  823.     return orig;
  824. }
  825.  
  826. char *strncpy(char *dest, const char *src, size_t n)
  827. {
  828.     char *orig = dest;
  829.    
  830.     while ((*(dest++) = *(src++)) && --n)
  831.         ;
  832.     return orig;
  833. }
  834.  
  835. char *strcat(char *dest, const char *src)
  836. {
  837.     char *orig = dest;
  838.     while (*dest++)
  839.         ;
  840.     --dest;
  841.     while ((*dest++ = *src++))
  842.         ;
  843.     return orig;
  844. }
  845.  
  846. char * strdup(const char *s1)
  847. {
  848.     size_t len = str_size(s1) + 1;
  849.     void *ret = malloc(len);
  850.  
  851.     if (ret == NULL)
  852.         return (char *) NULL;
  853.  
  854.     return (char *) memcpy(ret, s1, len);
  855. }
  856.  
  857. char *strtok(char *s, const char *delim)
  858. {
  859.     static char *next;
  860.  
  861.     return strtok_r(s, delim, &next);
  862. }
  863.  
  864. char *strtok_r(char *s, const char *delim, char **next)
  865. {
  866.     char *start, *end;
  867.  
  868.     if (s == NULL)
  869.         s = *next;
  870.  
  871.     /* Skip over leading delimiters. */
  872.     while (*s && (strchr(delim, *s) != NULL)) ++s;
  873.     start = s;
  874.  
  875.     /* Skip over token characters. */
  876.     while (*s && (strchr(delim, *s) == NULL)) ++s;
  877.     end = s;
  878.     *next = (*s ? s + 1 : s);
  879.  
  880.     if (start == end) {
  881.         return NULL;    /* No more tokens. */
  882.     }
  883.  
  884.     /* Overwrite delimiter with NULL terminator. */
  885.     *end = '\0';
  886.     return start;
  887. }
  888.  
  889. /** @}
  890.  */
  891.