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