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/ Gold Medal Software 2 / Gold Medal Software Volume 2 (Gold Medal) (1994).iso / os2 / cpostsrc.arj / TOKFILE.C < prev    next >
C/C++ Source or Header  |  1993-02-13  |  4KB  |  152 lines
  1. /*------------------------------------------------------------------
  2.  * tokfile.c :
  3.  *------------------------------------------------------------------
  4.  * 02-13-93 originally by Patrick J. Mueller
  5.  *------------------------------------------------------------------*/
  6.  
  7. #include <stdio.h>
  8. #include <stdlib.h>
  9. #include <string.h>
  10.  
  11. #include "tokfile.h"
  12.  
  13. /*------------------------------------------------------------------
  14.  * types
  15.  *------------------------------------------------------------------*/
  16. typedef struct
  17.    {
  18.    FILE *fHandle;
  19.    int   index;
  20.    int   length;
  21.    char  line[TOKFILE_MAX_LINE+1];
  22.    } TokFileData;
  23.  
  24. /*------------------------------------------------------------------
  25.  * open a file to be tokenized
  26.  *------------------------------------------------------------------*/
  27. TokFileInfo TokFileOpen(
  28.    char *fileName
  29.    )
  30.    {
  31.    TokFileData *tfd;
  32.  
  33.    /*---------------------------------------------------------------
  34.     * allocate memory for handle
  35.     *---------------------------------------------------------------*/
  36.    tfd = malloc(sizeof(TokFileData));
  37.    if (!tfd)
  38.       return NULL;
  39.  
  40.    memset(tfd,0,sizeof(TokFileData));
  41.  
  42.    /*---------------------------------------------------------------
  43.     * open the file
  44.     *---------------------------------------------------------------*/
  45.    if (!strcmp(fileName,"-"))
  46.       tfd->fHandle = stdin;
  47.    else
  48.       tfd->fHandle = fopen(fileName,"r");
  49.  
  50.    if (!tfd->fHandle)
  51.       {
  52.       free(tfd);
  53.       return NULL;
  54.       }
  55.  
  56.    /*---------------------------------------------------------------
  57.     * return handle
  58.     *---------------------------------------------------------------*/
  59.    return (TokFileInfo) tfd;
  60.    }
  61.  
  62. #define WHITE_SPACE " \a\b\f\n\r\t\v"
  63.  
  64. /*------------------------------------------------------------------
  65.  * get the next token from the file
  66.  *------------------------------------------------------------------*/
  67. char *TokFileNext(
  68.    TokFileInfo tfi
  69.    )
  70.    {
  71.    TokFileData *tfd = tfi;
  72.    char        *tok;
  73.  
  74.    if (!tfd)
  75.       return NULL;
  76.  
  77.    if (!tfd->fHandle)
  78.       return NULL;
  79.  
  80.    /*---------------------------------------------------------------
  81.     * loop trying to get the next token
  82.     *---------------------------------------------------------------*/
  83.    while (1)
  84.       {
  85.  
  86.       /*------------------------------------------------------------
  87.        * do we need to get another line
  88.        *------------------------------------------------------------*/
  89.       while (tfd->index >= tfd->length)
  90.          {
  91.          fgets(tfd->line,TOKFILE_MAX_LINE,tfd->fHandle);
  92.  
  93.          if (feof(tfd->fHandle))
  94.             {
  95.             fclose(tfd->fHandle);
  96.             free(tfd);
  97.             return NULL;
  98.             }
  99.  
  100.          tfd->length = strlen(tfd->line);
  101.          tfd->index  = strspn(tfd->line,WHITE_SPACE);
  102.  
  103.          /*---------------------------------------------------------
  104.           * check for comment
  105.           *---------------------------------------------------------*/
  106.          if ((tfd->index < tfd->length) && ('#' == tfd->line[tfd->index]))
  107.             tfd->index = tfd->length;
  108.          }
  109.  
  110.       /*------------------------------------------------------------
  111.        * skip past white space
  112.        *------------------------------------------------------------*/
  113.       tfd->index += strspn(tfd->line + tfd->index, WHITE_SPACE);
  114.  
  115.       if (tfd->index >= tfd->length)
  116.          continue;
  117.  
  118.       tok = tfd->line + tfd->index;
  119.  
  120.       /*------------------------------------------------------------
  121.        * skip past non-white space
  122.        *------------------------------------------------------------*/
  123.       tfd->index += strcspn(tfd->line + tfd->index, WHITE_SPACE);
  124.  
  125.       tfd->line[tfd->index] = 0;
  126.  
  127.       tfd->index++;
  128.  
  129.       return tok;
  130.       }
  131.  
  132.    return NULL;
  133.    }
  134.  
  135. #define TESTER_NOT
  136. #if defined(TESTER)
  137.  
  138. int main(void)
  139.    {
  140.    TokFileInfo  tfi;
  141.    char        *token;
  142.  
  143.    tfi = TokFileOpen("-");
  144.  
  145.    while (token = TokFileNext(tfi))
  146.       printf("%s\n",token);
  147.  
  148.    return 0;
  149.    }
  150.  
  151. #endif
  152.