/* chorder.c,  Sept 2007,  specifically for altering the order
   of columns in a file produced by prog8.c,  intended for
   Hectospec stuff.  */ 

  #define O_BINARY 0     
  /* (Above) O_BINARY must be 0 for unix or linux.  For windows, 
     however, comment this statement out.  */  

#define MAXSIZE 1000000  /* size of input array, also the output array */ 

#include <fcntl.h>    
#include <stdlib.h>  
#include <stdio.h>  

main()
 {
  char str[4000],filename1[42],filename2[42];  
  char *buffer1,*buffer2,colval[25][124];  

  int i,j,k,l,m,n,o,p,q;    
  int fd,filesize1a,filesize1b,filesize1c,filesize2,maxsize;
  int hdrlines,startp,p1,ncols1,coln,seq[25],ncols2,linenum;    
  int nbadrows,okrow;   

  buffer1 = malloc(MAXSIZE);       
  if (buffer1 == NULL)
   {  
    printf("\n***  Can\'t allocate %d bytes for buffer1[]  ***\n",MAXSIZE);   
    exit(0);  
   }
  buffer2 = malloc(MAXSIZE);       
  if (buffer2 == NULL)
   {  
    printf("\n***  Can\'t allocate %d bytes for buffer2[]  ***\n",MAXSIZE);   
    exit(0);  
   }

  printf("\n\n\n-------\n\n  O_BINARY = %d.   This should be 0 for a ");  
  printf("linux/unix computer,\n  but something else for a windows ");  
  printf("computer.  If incorrect, change\n  the \"#define O_BINARY 0\" "); 
  printf("near the beginning of the source code,\n  and recompile. ");  
  printf("  IF O_BINARY IS OK, HIT <ENTER> TO CONTINUE :  ");  
  gets(str);  if (str[0] == 'q') exit(0);  

  fd = -1; 
  while (fd < 0)
   {
    printf("\nInput file (ascii text file) :  ");  
    gets(str);  if (str[0] == 'q' && str[1] == '\0') exit(0);   
    for (i=0;i<40;i++) filename1[i] = str[i];  filename1[40] = '\0';  
    fd = open(filename1,O_BINARY|O_RDONLY);  
    if (fd < 0) printf("\n***  Can\'t open \"%s\"  ***\n",filename1);  
   }
    
  filesize1a = read(fd,buffer1,MAXSIZE);    close(fd);   fd = -1; 
  printf("Found %d bytes in \"%s\".\n",filesize1a,filename1);  

  if (filesize1a >= MAXSIZE) 
   {
    printf("\n***  File is too large for buffer;  increase MAXSIZE in source code  ***\n");     
    exit(0);  
   }
  if (filesize1a < 100)
   {
    printf("\n***  We expect at least 100 bytes in the file.  ***\n");  
    exit(0);  
   }

  /*  Replace tab characters with space characters ' ':  */
  n = 0;   
  for (p=0;p<filesize1a;p++)   
   { if (buffer1[p] == 9)  { buffer1[p] = ' ';  ++n; } }
  if (n) 
   printf("\n---  Have converted %d tab characters to spaces.\n",n);  

  /* delete bytes with decimal value 13 (associated with 
     MS-DOS end-of-line markers) */
  filesize1b = 0;   
  for (p=0;p<filesize1a;p++)  
    { if (buffer1[p] != 13)  buffer1[filesize1b++] = buffer1[p]; }
  n = filesize1a - filesize1b;  
  if (n) 
   {
    printf("\n---  Have deleted %d characters with decimal value 13,",n);
    printf("\n---  file size is now %d bytes.\n",filesize1b);
   }   

  /* delete empty text lines: */ 
  p = 0;  filesize1c = 0;  n = 0;     
  while (p < filesize1b)   
   { 
    k = 0; 
    for (j=p;j<filesize1b;j++)  
      { if (buffer1[j] == 10) break; if (buffer1[j] != ' ') k = 1; }
    if (k)   /* (copy the line only if it's not empty) */  
      { for (i=p;i<=j;i++) buffer1[filesize1c++] = buffer1[i];  } 
    else ++n;    /* n = number of deleted empty lines */  
    p = j + 1;  
   }
  if (n)
   {
    printf("\n---  Have deleted %d empty text lines;  ",n);  
    printf("\n---  File size is now %d bytes. \n",filesize1c); 
   }


  printf("\nHit <Enter> to continue :  ");  
  gets(str);  if (str[0] == 'q') exit(0);  

  m = 1000;  if (filesize1c < m) m = filesize1c;  
  sprintf(str,">|");   j = 2;  
  for (p=0;p<m;p++) 
   {
    str[j++] = buffer1[p];        
    if (buffer1[p] == 10 && (m-p) > 1)  
      { sprintf(&str[j],">|");  j = j + 2; }  
   } 
  str[j] = '\0';

  printf("\nFirst %d bytes of the file :\n\n%s\n",m,str);

                   /* ===-=== */  

  k = 0;  
  while (k != 1)
   {
    printf("\nSkip how many text lines?  ");   
    gets(str);  if (str[0] == 'q') exit(0);  
    k = sscanf(str,"%d",&hdrlines);   
    if (hdrlines < 0) k = 0;  
   }

  startp = 0;  
  if (hdrlines > 0)
   {
    n = 0;  
    for (p=0;p<filesize1c;p++) 
     {
      if (buffer1[p] == 10) ++n;   /* end-of-line */  
      if (n == hdrlines) { startp = p + 1; break; }
     }
    if (n < hdrlines)
     { 
      printf("\n***  Found only %d end-of-line characters  ***\n",n);  
      exit(0);   
     }
   }   

                  /* ===-=== */


  for (i=0;i<16;i++) colval[i][0] = '\0';

  k = 0;  coln = 0;  o = 0;   
  for (p=startp;p<filesize1c;p++)
   {
    colval[coln][o++] = buffer1[p];  
    if (buffer1[p] != ' ' && buffer1[p] != 10) k = 1;   
    else  
     {
      if (k) { colval[coln][o] = '\0';  ++coln;  o = 0;  k = 0;  }
     }   
    if (o >= 120)
     {
      printf("\n***  More than 120 characters in a column  ***\n");  
      exit(0);  
     }
    if (coln >= 24)  printf("\n***  Warning:  max 24 columns  ***\n");

    if (coln >= 24 || buffer1[p] == 10) break; 
   }
  ncols1 = coln;  
  if (ncols1 < 2) 
    { printf("\n***  Need at least two columns  ***\n");  exit(0); }

  printf("\nFound %d columns; entries in first row are",ncols1);  
  for (coln=0;coln<ncols1;coln++)
   {
    printf("\n%4d. %s ",coln+1,&colval[coln][0]);   
   }
  printf("\n");  

  ncols2 = 0;  
  while (ncols2 < 1)
   {
    for (i=0;i<24;i++) seq[i] = -1;  
    printf("\nNow list the columns you wish to copy, in the desired order "); 
    printf("of appearance.\nDuplications are allowed, and the maximum ");  
    printf("number of output columns is 24.\nList (1--24 items) :  "); 
    gets(str);  if (str[0] == 'q') exit(0);  
    ncols2 = sscanf(str,"%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d",&seq[0],&seq[1],&seq[2],&seq[3],&seq[4],&seq[5],&seq[6],&seq[7],&seq[8],&seq[9],&seq[10],&seq[11],&seq[12],&seq[13],&seq[14],&seq[15],&seq[16],&seq[17],&seq[18],&seq[19],&seq[20],&seq[21],&seq[22],&seq[23]);
    for (i=0;i<ncols2;i++)
     {
      if (seq[i] < 1 || seq[i] > ncols1)
       { 
        ncols2 = 0;  
        printf("\n***  All entries must be in range 1--%d  ***\n",ncols1);  
       }
      --seq[i];  
     }
   }

     /* ensure that the last character is a line break: */  
  if (buffer1[filesize1c-1] != 10) buffer1[filesize1c++] = 10;  

                     /* ===-=== */  

  p1 = startp;   nbadrows = 0;   
  filesize2 = 0; 

  for (linenum=0;p1<filesize1c;linenum++)
   { 
    for (i=0;i<16;i++) colval[i][0] = '\0';  
    okrow = 1;   

    k = 0;  coln = 0;  o = 0;  
    for (p=p1;p<filesize1c;p++)
     {
      colval[coln][o++] = buffer1[p];  
      if (buffer1[p] != ' ' && buffer1[p] != 10) k = 1;   
      else  
       {
        if (k) { colval[coln][o] = '\0';  ++coln;  o = 0;  k = 0;  }
       }   
      if (o >= 120 || coln >= 24) 
       { 
        okrow = 0;  
        for (i;i<filesize1c;i++) 
           { if (buffer1[i] == 10) { p = i; break; } } 
       }
      if (buffer1[p] == 10) { p1 = p + 1;  break; }
     }  /* p-loop */

    if (coln != ncols1) okrow = 0;   

    if (okrow)
     {
      for (j=0;j<ncols2;j++) 
       {
        for (i=0;i<120;i++)
         {  
          buffer2[filesize2] = colval[seq[j]][i];  
          if (buffer2[filesize2] == '\0') break;  else ++filesize2; 
          if (filesize2 >= MAXSIZE)  
           {
            printf("\n***  Output is incomplete, filled buffer2[]  ***\n");
            okrow = 0;  break;  
           } 
         }
        if (!okrow) break;  
       }
      buffer2[filesize2++] = ' ';    
     }

    if (!okrow)   /* don't substitute "else" */
     {
      ++nbadrows;  sprintf(&buffer2[filesize2],"BAD ROW  ");
      filesize2 = filesize2 + 8;  
     }

    buffer2[filesize2++] = 10;   /* end of line */ 

   }  /* linenum-loop */
   

  printf("\nHave copied approximately %d text lines.\n",linenum);

  close(fd); fd = -1;  
  while (fd < 0)
   { 
    printf("\nOutput file (new ascii file) :  ");  
    gets(str);  
    if (str[0] == 'q' && str[1] == '\0') 
     {
      printf("\n***  To avoid accidental loss of work, \'q\' exit doesn\'t work here.  ***\n     If you really want to quit with no output, use ctrl-C.\n");
     }
    else 
     {
      for (i=0;i<40;i++) filename2[i] = str[i];  filename2[40] = '\0';  
      k = open(filename2,O_BINARY|O_RDONLY);   
      if (k >= 0)
       {
        printf("\n***  \"%s\" already exists  ***\n",filename2); 
        close(k);
       }
      else
       {
        fd = open(filename2,O_CREAT|O_EXCL|O_BINARY|O_WRONLY,0666);  
        if (fd < 0) printf("\n***  Can\'t open \"%s\"  ***\n",filename2);   
       }
     }
   }

  o = write(fd,buffer2,filesize2);  
  if (o != filesize2)  printf("\n***  Write error  ***\n");  
  
  close(fd);  

  printf("\n---  Have created new file \"%s\"  ---\n",filename2);
    

 }  /* ----- end of program ----- */