Opening File Changing Case and Closing HW Help Code Included.

Thanks again ahead of time.

I am looking to write a program that opens a text file, takes the text and converts all characters (excluding special and numbers) to capital letters.

I am unsure where I am going wrong for some reason I am using d, and cannot get it to code correctly keep getting char to char error. Please let me know what I have messed up as I am a little confused.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#define MAXCHAR 250
int main(void)
{
   FILE *fp;
   char filename[MAXCHAR];
   char d;
  
   printf("Enter the name of the file to open\n");
   fgets(filename, MAXCHAR, stdin);
   filename[strlen(filename) - 1] = '\0';

   if  (!(fp = fopen(filename, "r+")))
   {
      printf("Unable to open %s\n", filename);
      exit(EXIT_FAILURE);
   }

  else
  {
       fgets(d,MAXCHAR,fp);
        if (fp > 'a' && fp < 'z')
        {
          fp = tolower(fp);
        }
        fputs(fp);
        }

   system("Pause");
   return 0;

}

What exactly are you trying to fputs? Even if that were correct, fgets has already moved the file pointer. So even if it were writing, it would be writing past the point you want it to. If you plan on doing this with one file, in one shot, you should:

Code:

read one character
    test it
        if it's to be replaced
            seek back one character
            write out the new character

Something like that. Also fp is a pointer to the file handle. You can't test it to see if it is a character. You simply read from and write to it. You don't test it directly usually for anything but NULL to see if it's failed to open or not.


Quzah.

Is this any better?

I am still getting an error at my if statement. I was unfortunately given the worst textbook on earth which provide no examples which relate anything to our assignments both graded and practice.

I am having to read wikipedia and here to learn to program in small segments.

i appreciate the help. I am just somewhat lost on this topic i guess the concept of counting within a file is confusing the heck out of me.

any examples would be great.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#define MAXCHAR 250
int main(void)
{
   FILE *fp;
   char filename[MAXCHAR];
   char d;
  
   printf("Enter the name of the file to open\n");
   fgets(filename, MAXCHAR, stdin);
   filename[strlen(filename) - 1] = '\0';

   if  (!(fp = fopen(filename, "r+")))
   {
      printf("Unable to open %s\n", filename);
      exit(EXIT_FAILURE);
   }

  else
  {
       fgets(d,MAXCHAR,filename);
        if (d > 'a' && d< 'z')
        {
          d = tolower(d);
        }
        }

   system("Pause");
   return 0;

}

If you're trying to read the entire file, you'll need some form of loop. Try writing a program that simply reads a file one character at a time until it has reached the end of file.

Once you're able to do this, try something like just printing out the lower case letters as you come across them, ignoring the rest. Then consider opening a file, doing the above, but instead of ignoring them all, writing the letters out to a new file as you reach tme.

Take small steps.


Quzah.

Erm, so why not just open an output file and just do read from one file and write to another?

Try that first, before trying in-place changes to a file.

Wouldn't you want toupper() since you want caps ?

yes i was being dumb with that.

I program in the AML language for robotics and doing that at work all day and trying to switch to C for school sucks.

Luckily this assignment isn't graded but i still need to complete tonight

I am hoping i can get it done we shal see.

okay here is an update

i guess my loop writing is very week.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#define MAXCHAR 250
int main(void)
{
   int c; /* for return value of fgetc */
   int inword = 0;
   FILE *fp;
   char filename[MAXCHAR];
   unsigned int count = 0;

   printf("Enter the name of the file to open\n");
   fgets(filename, MAXCHAR, stdin);
   filename[strlen(filename) - 1] = '\0';

   if  (!(fp = fopen(filename, "r")))
   {
      printf("Unable to open %s\n", filename);
      exit(EXIT_FAILURE);
   }

   while((c = fgetc(fp)) != EOF)
   {
      if(islower((unsigned char)c))
      {
         toupper(c);
      }
      }
   fclose(fp);

   printf("The file has been converted to all Capital letters.\n\n\n");
   system("Pause");
   return 0;

}

let me know what i am missing. I am hoping I got it to atleast open the file and close it. I am just having a problem scanning through and changing. maybe i am missing something small let me know.

- open input file for reading
- open output file for writing
- while((c = fgetc(fp)) != EOF)
-- if ( islower(c) ) c = toupper(c)
-- write to output file
- end while
- close input
- close output

here is an update I am at least writing to file now. except my output is MAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA and so on.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#define MAXCHAR 250
int main(void)
{
   int c; /* for return value of fgetc */
   FILE *fp, *fp2;
   char filename[MAXCHAR];
   
   printf("Enter the name of the file to open\n");
   fgets(filename, MAXCHAR, stdin);
   
   filename[strlen(filename) - 1] = '\0';
   fopen(filename,"r+");
   

   if  (!(fp = fopen(filename, "r+")))
   {
      printf("Unable to open %s\n", filename);
      exit(EXIT_FAILURE);
   }

   while((c = fgetc(fp)) != EOF)
   {
      c=toupper(c);
      fseek(fp,-1L,SEEK_SET);
      fputc(c,fp);
      }
      fclose(fp);    

   printf("\n\nThe file has been converted to all Capital letters.\n\n\n");
   system("Pause");
   return 0;

}

I avoid update mode because its a PITA. Can you read/write to separate files? Or use a temp file and rename?

Note changes

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#define MAXCHAR 250
int main(void)
{
   int c; /* for return value of fgetc */
   FILE *fp;
   char filename[MAXCHAR];
   
   printf("Enter the name of the file to open\n");
   fgets(filename, MAXCHAR, stdin);
   
   filename[strlen(filename) - 1] = '\0';

   /*!! fopen(filename,"r+"); */

   if  (!(fp = fopen(filename, "r+")))
   {
      printf("Unable to open %s\n", filename);
      exit(EXIT_FAILURE);
   }

   while((c = fgetc(fp)) != EOF)
   {
      c=toupper(c);
      fseek(fp,-1L,SEEK_CUR);/* back one char, not the beginning */
      fputc(c,fp);
      fflush(fp);
   }
   fclose(fp);    

   printf("\n\nThe file has been converted to all Capital letters.\n\n\n");
   return 0;
}