iolib.c

   1 /*
   2 ** iolib.c
   3 ** Input/output 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 <stdio.h>
  13 #include <ctype.h>
  14 #ifdef __GNUC__
  15 #include <floatingpoint.h>
  16 #endif
  17
  18 #include "lua.h"
  19
  20 static FILE *in=stdin, *out=stdout;
  21
  22 /*
  23 ** Open a file to read.
  24 ** LUA interface:
  25 **                      status = readfrom (filename)
  26 ** where:
  27 **                      status = 1 -> success
  28 **                      status = 0 -> error
  29 */
  30 static void io_readfrom (void)
  31 {
  32  lua_Object o = lua_getparam (1);
  33  if (o == NULL)                 /* restore standart input */
  34  {
  35   if (in != stdin)
  36   {
  37    fclose (in);
  38    in = stdin;
  39   }
  40   lua_pushnumber (1);
  41  }
  42  else
  43  {
  44   if (!lua_isstring (o))
  45   {
  46    lua_error ("incorrect argument to function 'readfrom`");
  47    lua_pushnumber (0);
  48   }
  49   else
  50   {
  51    FILE *fp = fopen (lua_getstring(o),"r");
  52    if (fp == NULL)
  53    {
  54     lua_pushnumber (0);
  55    }
  56    else
  57    {
  58     if (in != stdin) fclose (in);
  59     in = fp;
  60     lua_pushnumber (1);
  61    }
  62   }
  63  }
  64 }
  65
  66
  67 /*
  68 ** Open a file to write.
  69 ** LUA interface:
  70 **                      status = writeto (filename)
  71 ** where:
  72 **                      status = 1 -> success
  73 **                      status = 0 -> error
  74 */
  75 static void io_writeto (void)
  76 {
  77  lua_Object o = lua_getparam (1);
  78  if (o == NULL)                 /* restore standart output */
  79  {
  80   if (out != stdout)
  81   {
  82    fclose (out);
  83    out = stdout;
  84   }
  85   lua_pushnumber (1);
  86  }
  87  else
  88  {
  89   if (!lua_isstring (o))
  90   {
  91    lua_error ("incorrect argument to function 'writeto`");
  92    lua_pushnumber (0);
  93   }
  94   else
  95   {
  96    FILE *fp = fopen (lua_getstring(o),"w");
  97    if (fp == NULL)
  98    {
  99     lua_pushnumber (0);
 100    }
 101    else
 102    {
 103     if (out != stdout) fclose (out);
 104     out = fp;
 105     lua_pushnumber (1);
 106    }
 107   }
 108  }
 109 }
 110
 111
 112 /*
 113 ** Read a variable. On error put nil on stack.
 114 ** LUA interface:
 115 **                      variable = read ([format])
 116 **
 117 ** O formato pode ter um dos seguintes especificadores:
 118 **
 119 **      s ou S -> para string
 120 **      f ou F, g ou G, e ou E -> para reais
 121 **      i ou I -> para inteiros
 122 **
 123 **      Estes especificadores podem vir seguidos de numero que representa
 124 **      o numero de campos a serem lidos.
 125 */
 126 static void io_read (void)
 127 {
 128  lua_Object o = lua_getparam (1);
 129  if (o == NULL)                 /* free format */
 130  {
 131   int c;
 132   char s[256];
 133   while (isspace(c=fgetc(in)))
 134    ;
 135   if (c == '\"')
 136   {
 137    if (fscanf (in, "%[^\"]\"", s) != 1)
 138    {
 139     lua_pushnil ();
 140     return;
 141    }
 142   }
 143   else if (c == '\'')
 144   {
 145    if (fscanf (in, "%[^\']\'", s) != 1)
 146    {
 147     lua_pushnil ();
 148     return;
 149    }
 150   }
 151   else
 152   {
 153    char *ptr;
 154    double d;
 155    ungetc (c, in);
 156    if (fscanf (in, "%s", s) != 1)
 157    {
 158     lua_pushnil ();
 159     return;
 160    }
 161    d = strtod (s, &ptr);
 162    if (!(*ptr))
 163    {
 164     lua_pushnumber (d);
 165     return;
 166    }
 167   }
 168   lua_pushstring (s);
 169   return;
 170  }
 171  else                           /* formatted */
 172  {
 173   char *e = lua_getstring(o);
 174   char t;
 175   int  m=0;
 176   while (isspace(*e)) e++;
 177   t = *e++;
 178   while (isdigit(*e))
 179    m = m*10 + (*e++ - '0');
 180
 181   if (m > 0)
 182   {
 183    char f[80];
 184    char s[256];
 185    sprintf (f, "%%%ds", m);
 186    fscanf (in, f, s);
 187    switch (tolower(t))
 188    {
 189     case 'i':
 190     {
 191      long int l;
 192      sscanf (s, "%ld", &l);
 193      lua_pushnumber(l);
 194     }
 195     break;
 196     case 'f': case 'g': case 'e':
 197     {
 198      float f;
 199      sscanf (s, "%f", &f);
 200      lua_pushnumber(f);
 201     }
 202     break;
 203     default:
 204      lua_pushstring(s);
 205     break;
 206    }
 207   }
 208   else
 209   {
 210    switch (tolower(t))
 211    {
 212     case 'i':
 213     {
 214      long int l;
 215      fscanf (in, "%ld", &l);
 216      lua_pushnumber(l);
 217     }
 218     break;
 219     case 'f': case 'g': case 'e':
 220     {
 221      float f;
 222      fscanf (in, "%f", &f);
 223      lua_pushnumber(f);
 224     }
 225     break;
 226     default:
 227     {
 228      char s[256];
 229      fscanf (in, "%s", s);
 230      lua_pushstring(s);
 231     }
 232     break;
 233    }
 234   }
 235  }
 236 }
 237
 238
 239 /*
 240 ** Write a variable. On error put 0 on stack, otherwise put 1.
 241 ** LUA interface:
 242 **                      status = write (variable [,format])
 243 **
 244 ** O formato pode ter um dos seguintes especificadores:
 245 **
 246 **      s ou S -> para string
 247 **      f ou F, g ou G, e ou E -> para reais
 248 **      i ou I -> para inteiros
 249 **
 250 **      Estes especificadores podem vir seguidos de:
 251 **
 252 **              [?][m][.n]
 253 **
 254 **      onde:
 255 **              ? -> indica justificacao
 256 **                      < = esquerda
 257 **                      | = centro
 258 **                      > = direita (default)
 259 **              m -> numero maximo de campos (se exceder estoura)
 260 **              n -> indica precisao para
 261 **                      reais -> numero de casas decimais
 262 **                      inteiros -> numero minimo de digitos
 263 **                      string -> nao se aplica
 264 */
 265 static char *buildformat (char *e, lua_Object o)
 266 {
 267  static char buffer[512];
 268  static char f[80];
 269  char *string = &buffer[255];
 270  char t, j='r';
 271  int  m=0, n=0, l;
 272  while (isspace(*e)) e++;
 273  t = *e++;
 274  if (*e == '<' || *e == '|' || *e == '>') j = *e++;
 275  while (isdigit(*e))
 276   m = m*10 + (*e++ - '0');
 277  e++;   /* skip point */
 278  while (isdigit(*e))
 279   n = n*10 + (*e++ - '0');
 280
 281  sprintf(f,"%%");
 282  if (j == '<' || j == '|') sprintf(strchr(f,0),"-");
 283  if (m != 0)   sprintf(strchr(f,0),"%d", m);
 284  if (n != 0)   sprintf(strchr(f,0),".%d", n);
 285  sprintf(strchr(f,0), "%c", t);
 286  switch (tolower(t))
 287  {
 288   case 'i': t = 'i';
 289    sprintf (string, f, (long int)lua_getnumber(o));
 290   break;
 291   case 'f': case 'g': case 'e': t = 'f';
 292    sprintf (string, f, (float)lua_getnumber(o));
 293   break;
 294   case 's': t = 's';
 295    sprintf (string, f, lua_getstring(o));
 296   break;
 297   default: return "";
 298  }
 299  l = strlen(string);
 300  if (m!=0 && l>m)
 301  {
 302   int i;
 303   for (i=0; i<m; i++)
 304    string[i] = '*';
 305   string[i] = 0;
 306  }
 307  else if (m!=0 && j=='|')
 308  {
 309   int i=l-1;
 310   while (isspace(string[i])) i--;
 311   string -= (m-i) / 2;
 312   i=0;
 313   while (string[i]==0) string[i++] = ' ';
 314   string[l] = 0;
 315  }
 316  return string;
 317 }
 318 static void io_write (void)
 319 {
 320  lua_Object o1 = lua_getparam (1);
 321  lua_Object o2 = lua_getparam (2);
 322  if (o1 == NULL)                        /* new line */
 323  {
 324   fprintf (out, "\n");
 325   lua_pushnumber(1);
 326  }
 327  else if (o2 == NULL)                   /* free format */
 328  {
 329   int status=0;
 330   if (lua_isnumber(o1))
 331    status = fprintf (out, "%g", lua_getnumber(o1));
 332   else if (lua_isstring(o1))
 333    status = fprintf (out, "%s", lua_getstring(o1));
 334   lua_pushnumber(status);
 335  }
 336  else                                   /* formated */
 337  {
 338   if (!lua_isstring(o2))
 339   {
 340    lua_error ("incorrect format to function `write'");
 341    lua_pushnumber(0);
 342    return;
 343   }
 344   lua_pushnumber(fprintf (out, "%s", buildformat(lua_getstring(o2),o1)));
 345  }
 346 }
 347
 348 /*
 349 ** Execute a executable program using "sustem".
 350 ** On error put 0 on stack, otherwise put 1.
 351 */
 352 void io_execute (void)
 353 {
 354  lua_Object o = lua_getparam (1);
 355  if (o == NULL || !lua_isstring (o))
 356  {
 357   lua_error ("incorrect argument to function 'execute`");
 358   lua_pushnumber (0);
 359  }
 360  else
 361  {
 362   system(lua_getstring(o));
 363   lua_pushnumber (1);
 364  }
 365  return;
 366 }
 367
 368 /*
 369 ** Remove a file.
 370 ** On error put 0 on stack, otherwise put 1.
 371 */
 372 void io_remove  (void)
 373 {
 374  lua_Object o = lua_getparam (1);
 375  if (o == NULL || !lua_isstring (o))
 376  {
 377   lua_error ("incorrect argument to function 'execute`");
 378   lua_pushnumber (0);
 379  }
 380  else
 381  {
 382   if (remove(lua_getstring(o)) == 0)
 383    lua_pushnumber (1);
 384   else
 385    lua_pushnumber (0);
 386  }
 387  return;
 388 }
 389
 390 /*
 391 ** Open io library
 392 */
 393 void iolib_open (void)
 394 {
 395  lua_register ("readfrom", io_readfrom);
 396  lua_register ("writeto",  io_writeto);
 397  lua_register ("read",     io_read);
 398  lua_register ("write",    io_write);
 399  lua_register ("execute",  io_execute);
 400  lua_register ("remove",   io_remove);
 401 }