cgi-bin/var.c

   1 /*
   2  * "$Id: var.c,v 1.5 1997/05/13 16:38:07 mike Exp $"
   3  *
   4  *   CGI form variable functions.
   5  *
   6  *   Copyright 1997 by Easy Software Products, All Rights Reserved.
   7  *
   8  * Contents:
   9  *
  10  *   cgiInitialize()         - Initialize the CGI variable "database"...
  11  *   cgiCheckVariables()     - Check for the presence of "required" variables.
  12  *   cgiGetVariable()        - Get a CGI variable from the database...
  13  *   cgiSetVariable()        - Set a CGI variable in the database...
  14  *   cgi_sort_variables()    - Sort all form variables for faster lookup.
  15  *   cgi_compare_variables() - Compare two variables.
  16  *   cgi_add_variable()      - Add a form variable.
  17  *   cgi_initialize_string() - Initialize form variables from a string.
  18  *   cgi_initialize_get()    - Initialize form variables using the GET method.
  19  *   cgi_initialize_post()   - Initialize variables using the POST method.
  20  *
  21  * Revision History:
  22  *
  23  *   $Log: var.c,v $
  24  *   Revision 1.5  1997/05/13 16:38:07  mike
  25  *   Fixed a bug in the cgi_initialize_string() code - was not sorting vars!
  26  *
  27  *   Revision 1.4  1997/05/13  15:16:30  mike
  28  *   Updated cgiCheckVariables() to see if the variable is blank.
  29  *
  30  *   Revision 1.3  1997/05/13  14:56:37  mike
  31  *   Added cgiCheckVariables() function to check for required variables.
  32  *
  33  *   Revision 1.2  1997/05/08  20:14:19  mike
  34  *   Renamed CGI_Name functions to cgiName functions.
  35  *   Updated documentation.
  36  *
  37  *   Revision 1.1  1997/05/08  19:55:53  mike
  38  *   Initial revision
  39  */
  40
  41 /*#define DEBUG*/
  42 #include "cgi.h"
  43
  44
  45 /*
  46  * Data structure to hold all the CGI form variables...
  47  */
  48
  49 typedef struct
  50 {
  51   char  *name,  /* Name of variable */
  52         *value; /* Value of variable */
  53 } var_t;
  54
  55
  56 /*
  57  * Local globals...
  58  */
  59
  60 static int      form_count = 0;         /* Form variable count */
  61 static var_t    *form_vars = NULL;      /* Form variables */
  62
  63
  64 /*
  65  * Local functions...
  66  */
  67
  68 static void     cgi_sort_variables(void);
  69 static int      cgi_compare_variables(var_t *v1, var_t *v2);
  70 static void     cgi_add_variable(char *name, char *value);
  71 static void     cgi_initialize_string(char *data);
  72 static int      cgi_initialize_get(int need_content);
  73 static int      cgi_initialize_post(int need_content);
  74
  75
  76 /*
  77  * 'cgiInitialize()' - Initialize the CGI variable "database"...
  78  */
  79
  80 int
  81 cgiInitialize(int need_content) /* I - True if input is required */
  82 {
  83   char  *method;                /* Form posting method */
  84
  85
  86 #ifdef DEBUG
  87   setbuf(stdout, NULL);
  88   puts("Content-type: text/plain\n");
  89 #endif /* DEBUG */
  90
  91   method = getenv("REQUEST_METHOD");
  92
  93   if (method == NULL)
  94     return (!need_content);
  95
  96   if (strcasecmp(method, "GET") == 0)
  97     return (cgi_initialize_get(need_content));
  98   else if (strcasecmp(method, "POST") == 0)
  99     return (cgi_initialize_post(need_content));
 100   else
 101     return (!need_content);
 102 }
 103
 104
 105 /*
 106  * 'cgiCheckVariables()' - Check for the presence of "required" variables.
 107  *
 108  * Returns 1 if all variables are present, 0 otherwise.  Name may be separated
 109  * by spaces and/or commas.
 110  */
 111
 112 int
 113 cgiCheckVariables(char *names)  /* I - Variables to look for */
 114 {
 115   char  name[255],      /* Current variable name */
 116         *s,             /* Pointer in string */
 117         *val;           /* Value of variable */
 118
 119
 120   if (names == NULL)
 121     return (1);
 122
 123   while (*names != '\0')
 124   {
 125     while (*names == ' ' || *names == ',')
 126       names ++;
 127
 128     for (s = name; *names != '\0' && *names != ' ' && *names != ','; s ++, names ++)
 129       *s = *names;
 130
 131     *s = 0;
 132     if (name[0] == '\0')
 133       break;
 134
 135     if ((val = cgiGetVariable(name)) == NULL)
 136       return (0);
 137
 138     if (*val == '\0')
 139       return (0);       /* Can't be blank, either! */
 140   };
 141
 142   return (1);
 143 }
 144
 145
 146 /*
 147  * 'cgiGetVariable()' - Get a CGI variable from the database...
 148  *
 149  * Returns NULL if the variable doesn't exist...
 150  */
 151
 152 char *
 153 cgiGetVariable(char *name)      /* I - Name of variable */
 154 {
 155   var_t key,    /* Search key */
 156         *var;   /* Returned variable */
 157
 158
 159   if (form_count < 1)
 160     return (NULL);
 161
 162   key.name = name;
 163
 164   var = bsearch(&key, form_vars, form_count, sizeof(var_t),
 165                 (int (*)(const void *, const void *))cgi_compare_variables);
 166
 167 #ifdef DEBUG
 168   if (var == NULL)
 169     printf("cgiGetVariable(\"%s\") is returning NULL...\n", name);
 170   else
 171     printf("cgiGetVariable(\"%s\") is returning \"%s\"...\n", name, var->value);
 172 #endif /* DEBUG */
 173
 174   return ((var == NULL) ? NULL : var->value);
 175 }
 176
 177
 178 /*
 179  * 'cgiSetVariable()' - Set a CGI variable in the database...
 180  */
 181
 182 void
 183 cgiSetVariable(char *name,      /* I - Name of variable */
 184                char *value)     /* I - Value of variable */
 185 {
 186   var_t key,    /* Search key */
 187         *var;   /* Returned variable */
 188
 189
 190   if (form_count > 0)
 191   {
 192     key.name = name;
 193
 194     var = bsearch(&key, form_vars, form_count, sizeof(var_t),
 195                   (int (*)(const void *, const void *))cgi_compare_variables);
 196   }
 197   else
 198     var = NULL;
 199
 200   if (var == NULL)
 201   {
 202     cgi_add_variable(name, value);
 203     cgi_sort_variables();
 204   }
 205   else
 206   {
 207     free(var->value);
 208     var->value = strdup(value);
 209   };
 210 }
 211
 212
 213 /*
 214  * 'cgi_sort_variables()' - Sort all form variables for faster lookup.
 215  */
 216
 217 static void
 218 cgi_sort_variables(void)
 219 {
 220 #ifdef DEBUG
 221   int   i;
 222
 223
 224   puts("Sorting variables...");
 225 #endif /* DEBUG */
 226
 227   if (form_count < 2)
 228     return;
 229
 230   qsort(form_vars, form_count, sizeof(var_t),
 231         (int (*)(const void *, const void *))cgi_compare_variables);
 232
 233 #ifdef DEBUG
 234   puts("New variable list is:");
 235   for (i = 0; i < form_count; i ++)
 236     printf("%s = %s\n", form_vars[i].name, form_vars[i].value);
 237 #endif /* DEBUG */
 238 }
 239
 240
 241 /*
 242  * 'cgi_compare_variables()' - Compare two variables.
 243  */
 244
 245 static int
 246 cgi_compare_variables(var_t *v1,        /* I - First variable */
 247                       var_t *v2)        /* I - Second variable */
 248 {
 249   return (strcasecmp(v1->name, v2->name));
 250 }
 251
 252
 253 /*
 254  * 'cgi_add_variable()' - Add a form variable.
 255  */
 256
 257 static void
 258 cgi_add_variable(char *name,            /* I - Variable name */
 259                  char *value)           /* I - Variable value */
 260 {
 261   var_t *var;
 262
 263
 264 #ifdef DEBUG
 265   printf("Adding variable \'%s\' with value \'%s\'...\n", name, value);
 266 #endif /* DEBUG */
 267
 268   if (form_count == 0)
 269     form_vars = malloc(sizeof(var_t));
 270   else
 271     form_vars = realloc(form_vars, (form_count + 1) * sizeof(var_t));
 272
 273   var        = form_vars + form_count;
 274   var->name  = strdup(name);
 275   var->value = strdup(value);
 276   form_count ++;
 277 }
 278
 279
 280 /*
 281  * 'cgi_initialize_string()' - Initialize form variables from a string.
 282  */
 283
 284 static void
 285 cgi_initialize_string(char *data)       /* I - Form data string */
 286 {
 287   int   done;           /* True if we're done reading a form variable */
 288   char  *s,             /* Pointer to current form string */
 289         ch,             /* Temporary character */
 290         name[255],      /* Name of form variable */
 291         value[65536];   /* Variable value... */
 292
 293
 294  /*
 295   * Check input...
 296   */
 297
 298   if (data == NULL)
 299     return;
 300
 301  /*
 302   * Loop until we've read all the form data...
 303   */
 304
 305   while (*data != '\0')
 306   {
 307    /*
 308     * Get the variable name...
 309     */
 310
 311     for (s = name; *data != '\0'; data ++, s ++)
 312       if (*data == '=')
 313         break;
 314       else
 315         *s = *data;
 316
 317     *s = '\0';
 318     if (*data == '=')
 319       data ++;
 320
 321    /*
 322     * Read the variable value...
 323     */
 324
 325     for (s = value, done = 0; !done && *data != '\0'; data ++, s ++)
 326       switch (*data)
 327       {
 328         case '&' :      /* End of data... */
 329             done = 1;
 330             s --;
 331             break;
 332
 333         case '+' :      /* Escaped space character */
 334             *s = ' ';
 335             break;
 336
 337         case '%' :      /* Escaped control character */
 338            /*
 339             * Read the hex code from stdin...
 340             */
 341
 342             data ++;
 343             ch = *data - '0';
 344             if (ch > 9)
 345               ch -= 7;
 346             *s = ch << 4;
 347
 348             data ++;
 349             ch = *data - '0';
 350             if (ch > 9)
 351               ch -= 7;
 352             *s |= ch;
 353             break;
 354
 355         default :       /* Other characters come straight through */
 356             *s = *data;
 357             break;
 358       };
 359
 360     *s = '\0';          /* nul terminate the string */
 361
 362    /*
 363     * Add the string to the variable "database"...
 364     */
 365
 366     cgi_add_variable(name, value);
 367   };
 368
 369   cgi_sort_variables();
 370 }
 371
 372
 373 /*
 374  * 'cgi_initialize_get()' - Initialize form variables using the GET method.
 375  */
 376
 377 static int
 378 cgi_initialize_get(int need_content)    /* I - True if input is required */
 379 {
 380   char  *data;  /* Pointer to form data string */
 381
 382
 383 #ifdef DEBUG
 384   puts("Initializing variables using GET method...");
 385 #endif /* DEBUG */
 386
 387  /*
 388   * Check to see if there is anything for us to read...
 389   */
 390
 391   data = getenv("QUERY_STRING");
 392   if (data == NULL)
 393     return (!need_content);
 394
 395  /*
 396   * Parse it out...
 397   */
 398
 399   cgi_initialize_string(data);
 400
 401  /*
 402   * Return...
 403   */
 404
 405   return (1);
 406 }
 407
 408
 409 /*
 410  * 'cgi_initialize_post()' - Initialize variables using the POST method.
 411  */
 412
 413 static int
 414 cgi_initialize_post(int need_content)   /* I - True if input is required */
 415 {
 416   char  *content_length,        /* Length of input data (string) */
 417         *data;                  /* Pointer to form data string */
 418   int   length,                 /* Length of input data */
 419         nbytes,                 /* Number of bytes read this read() */
 420         tbytes;                 /* Total number of bytes read */
 421
 422
 423 #ifdef DEBUG
 424   puts("Initializing variables using POST method...");
 425 #endif /* DEBUG */
 426
 427  /*
 428   * Check to see if there is anything for us to read...
 429   */
 430
 431   content_length = getenv("CONTENT_LENGTH");
 432   if (content_length == NULL)
 433     return (!need_content);
 434
 435  /*
 436   * Get the length of the input stream and allocate a buffer for it...
 437   */
 438
 439   length = atoi(content_length);
 440   data   = malloc(length + 1);
 441
 442  /*
 443   * Read the data into the buffer...
 444   */
 445
 446   for (tbytes = 0; tbytes < length; tbytes += nbytes)
 447     if ((nbytes = read(0, data + tbytes, length - tbytes)) < 0)
 448     {
 449       free(data);
 450       return (!need_content);
 451     };
 452
 453   data[length] = '\0';
 454
 455  /*
 456   * Parse it out...
 457   */
 458
 459   cgi_initialize_string(data);
 460
 461  /*
 462   * Free the data and return...
 463   */
 464
 465   free(data);
 466
 467   return (1);
 468 }
 469
 470
 471 /*
 472  * End of "$Id: var.c,v 1.5 1997/05/13 16:38:07 mike Exp $".
 473  */