strlib.c

   1 /*
   2 ** strlib.c
   3 ** String library to LUA
   4 **
   5 ** Waldemar Celes Filho
   6 ** TeCGraf - PUC-Rio
   7 ** 19 May 93
   8 */
   9
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <ctype.h>
  13
  14
  15 #include "lua.h"
  16
  17 /*
  18 ** Return the position of the first caracter of a substring into a string
  19 ** LUA interface:
  20 **                      n = strfind (string, substring)
  21 */
  22 static void str_find (void)
  23 {
  24  int n;
  25  char *s1, *s2;
  26  lua_Object o1 = lua_getparam (1);
  27  lua_Object o2 = lua_getparam (2);
  28  if (!lua_isstring(o1) || !lua_isstring(o2))
  29  { lua_error ("incorrect arguments to function `strfind'"); return; }
  30  s1 = lua_getstring(o1);
  31  s2 = lua_getstring(o2);
  32  n = strstr(s1,s2) - s1 + 1;
  33  lua_pushnumber (n);
  34 }
  35
  36 /*
  37 ** Return the string length
  38 ** LUA interface:
  39 **                      n = strlen (string)
  40 */
  41 static void str_len (void)
  42 {
  43  lua_Object o = lua_getparam (1);
  44  if (!lua_isstring(o))
  45  { lua_error ("incorrect arguments to function `strlen'"); return; }
  46  lua_pushnumber(strlen(lua_getstring(o)));
  47 }
  48
  49
  50 /*
  51 ** Return the substring of a string, from start to end
  52 ** LUA interface:
  53 **                      substring = strsub (string, start, end)
  54 */
  55 static void str_sub (void)
  56 {
  57  int start, end;
  58  char *s;
  59  lua_Object o1 = lua_getparam (1);
  60  lua_Object o2 = lua_getparam (2);
  61  lua_Object o3 = lua_getparam (3);
  62  if (!lua_isstring(o1) || !lua_isnumber(o2) || !lua_isnumber(o3))
  63  { lua_error ("incorrect arguments to function `strsub'"); return; }
  64  s = strdup (lua_getstring(o1));
  65  start = lua_getnumber (o2);
  66  end = lua_getnumber (o3);
  67  if (end < start || start < 1 || end > strlen(s))
  68   lua_pushstring ("");
  69  else
  70  {
  71   s[end] = 0;
  72   lua_pushstring (&s[start-1]);
  73  }
  74  free (s);
  75 }
  76
  77 /*
  78 ** Convert a string to lower case.
  79 ** LUA interface:
  80 **                      lowercase = strlower (string)
  81 */
  82 static void str_lower (void)
  83 {
  84  char *s, *c;
  85  lua_Object o = lua_getparam (1);
  86  if (!lua_isstring(o))
  87  { lua_error ("incorrect arguments to function `strlower'"); return; }
  88  c = s = strdup(lua_getstring(o));
  89  while (*c != 0)
  90  {
  91   *c = tolower(*c);
  92   c++;
  93  }
  94  lua_pushstring(s);
  95  free(s);
  96 }
  97
  98
  99 /*
 100 ** Convert a string to upper case.
 101 ** LUA interface:
 102 **                      uppercase = strupper (string)
 103 */
 104 static void str_upper (void)
 105 {
 106  char *s, *c;
 107  lua_Object o = lua_getparam (1);
 108  if (!lua_isstring(o))
 109  { lua_error ("incorrect arguments to function `strlower'"); return; }
 110  c = s = strdup(lua_getstring(o));
 111  while (*c != 0)
 112  {
 113   *c = toupper(*c);
 114   c++;
 115  }
 116  lua_pushstring(s);
 117  free(s);
 118 }
 119
 120
 121 /*
 122 ** Open string library
 123 */
 124 void strlib_open (void)
 125 {
 126  lua_register ("strfind", str_find);
 127  lua_register ("strlen", str_len);
 128  lua_register ("strsub", str_sub);
 129  lua_register ("strlower", str_lower);
 130  lua_register ("strupper", str_upper);
 131 }