Thread: Help with File operations

Dear All,
My task is as follows:-
1. I have to open file :CAN.c

2. find preprocessor directive

3. If preprocessor directive is Capital then i have to convert it into Lower

Ex:- #include<CAN.c>---------------->#include<can.c>

4. write it into other file

so for i have done as follows:-

Code:

#include "stdafx.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main(int argc,char **argv)
{
  const int max=1024;
  int r=0,i;
  FILE *in,*out;
  in=fopen("C:\\Documents and Settings\\syg4kor\\Desktop\\Perl_Programming\\CAN.c","rb");
  out=fopen("C:\\Documents and Settings\\syg4kor\\Desktop\\Perl_Programming\\CAN_CPY.c","wb");
  char buff[max+3];

  if (argc!=3)
  {
    r=1;
    printf("usage: lower <src> <dest>\n");
  }
  else if ((in=fopen(argv[1],"rb"))==NULL)
    {
      r=2;
      printf("cannot open input-file!\n");
    }
    else if ((out=fopen(argv[2],"wb"))==NULL) // Output file will be overwritten when exists !!!
      {
        r=3;
        printf("cannot open output-file!\n");
	}
      else
      {
        while (!feof(in))
        {
          buff[0]=0;
          fgets(buff,max,in);

          for (i=0;i<max && buff[i]!=NULL && &buff[i]!='\r' && buff[i]!='\n' && (buff[i]==' ' || buff[i]=='\t');i++);
          if (buff[i]=='#')
          {
            for (i=i+1;i<max && buff[i]!=NULL && buff[i]!='\r' && buff[i]!='\n';i++)
            {
              buff[i]=tolower(buff[i]);
            }
          }

          fputs(buff,out);
	  }

        fclose(out);
      }

      fclose(in);

  return 0;
}

But i am getting following errors in highleghed line:

1. error C2446: '!=' : no conversion from 'int' to 'char *'

2. error C2040: '!=' : 'char *' differs in levels of indirection from 'int'

can anybody help me..actually i am learning C programming using this sight..this sight really very helpfull for learning C..i am thankful to all of you

Code:

#include "stdafx.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main(int argc,char **argv)
{
  const int max=1024;
  int r=0,i;
  FILE *in,*out;
  in=fopen("C:\\Documents and Settings\\syg4kor\\Desktop\\Perl_Programming\\CAN.c","rb");
  out=fopen("C:\\Documents and Settings\\syg4kor\\Desktop\\Perl_Programming\\CAN_CPY.c","wb");
  char buff[max+3];

  if (argc!=3)
  {
    r=1;
    printf("usage: lower <src> <dest>\n");
  }
  else if ((in=fopen(argv[1],"rb"))==NULL)
    {
      r=2;
      printf("cannot open input-file!\n");
    }
    else if ((out=fopen(argv[2],"wb"))==NULL) // Output file will be overwritten when exists !!!
      {
        r=3;
        printf("cannot open output-file!\n");
    }
      else
      {
        while (!feof(in))
        {
          buff[0]=0;
          fgets(buff,max,in);

          for (i=0;i<max && buff[i]!=NULL && &buff[i]!='\r' && buff[i]!='\n' && (buff[i]==' ' || buff[i]=='\t');i++);
          if (buff[i]=='#')
          {
            for (i=i+1;i<max && buff[i]!=NULL && buff[i]!='\r' && buff[i]!='\n';i++)
            {
              buff[i]=tolower(buff[i]);
            }
          }

          fputs(buff,out);
      }

        fclose(out);
      }

      fclose(in);

  return 0;
}

Can you catch the errors highlighted in RED?

Thanks manav it is working...

Originally Posted by manav

Code:

#include "stdafx.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main(int argc,char **argv)
{
  const int max=1024;
  int r=0,i;
  FILE *in,*out;
  in=fopen("C:\\Documents and Settings\\syg4kor\\Desktop\\Perl_Programming\\CAN.c","rb");
  out=fopen("C:\\Documents and Settings\\syg4kor\\Desktop\\Perl_Programming\\CAN_CPY.c","wb");
  char buff[max+3];

  if (argc!=3)
  {
    r=1;
    printf("usage: lower <src> <dest>\n");
  }
  else if ((in=fopen(argv[1],"rb"))==NULL)
    {
      r=2;
      printf("cannot open input-file!\n");
    }
    else if ((out=fopen(argv[2],"wb"))==NULL) // Output file will be overwritten when exists !!!
      {
        r=3;
        printf("cannot open output-file!\n");
    }
      else
      {
        while (!feof(in))
        {
          buff[0]=0;
          fgets(buff,max,in);

          for (i=0;i<max && buff[i]!=NULL && &buff[i]!='\r' && buff[i]!='\n' && (buff[i]==' ' || buff[i]=='\t');i++);
          if (buff[i]=='#')
          {
            for (i=i+1;i<max && buff[i]!=NULL && buff[i]!='\r' && buff[i]!='\n';i++)
            {
              buff[i]=tolower(buff[i]);
            }
          }

          fputs(buff,out);
      }

        fclose(out);
      }

      fclose(in);

  return 0;
}

Can you catch the errors highlighted in RED?

I have rectifed the errors..but i am not getting correct result...

present:- Output file successufully created in present directory with empty

required:- Output file should creat as copy of original with

all Upper preprocessor directives replaced with lower preprocessor directives
ex:- #include<CAN.h>------>#include<can.h>

Code:

#include "stdafx.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main(int argc,char **argv)
{
  const int max=1024;
  int r=0,i;
  FILE *in,*out;
  in=fopen("C:\\Documents and Settings\\syg4kor\\Desktop\\Perl_Programming\\CAN.c","rb");
  out=fopen("C:\\Documents and Settings\\syg4kor\\Desktop\\Perl_Programming\\CAN_CPY.c","wb");
  char buff[max+3];

  if (argc!=3)
  {
    r=1;
    printf("usage: lower <src> <dest>\n");
  }
  else if ((in=fopen(argv[1],"rb"))==NULL)
    {
      r=2;
      printf("cannot open input-file!\n");
    }
    else if ((out=fopen(argv[2],"wb"))==NULL) // Output file will be overwritten when exists !!!
      {
        r=3;
        printf("cannot open output-file!\n");
	}
      else
      {
        while (!feof(in))
        {
          buff[0]=0;
          fgets(buff,max,in);

          for (i=0;i<max && buff[i]!='0' && buff[i]!='\r' && buff[i]!='\n' && (buff[i]==' ' || buff[i]=='\t');i++);

          if (buff[i]=='#')
          {
            for (i=i+1;i<max && buff[i]!='0' && buff[i]!='\r' && buff[i]!='\n';i++)
            {
              buff[i]=tolower(buff[i]);
            }
          }

          fputs(buff,out);
	  }

        fclose(out);
      }

      fclose(in);

  return 0;
}

Code:

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

int main(int argc,char **argv)
{
    const int max=1024;
    int r=0,i;
    FILE *in,*out;
    char buff[max+3];

    if (argc!=3)
    {
        r=1;
        printf("usage: lower <src> <dest>\n");
    }
    else if ((in=fopen(argv[1],"rb"))==NULL)
    {
        r=2;
        printf("cannot open input-file!\n");
    }
    else if ((out=fopen(argv[2],"wb"))==NULL) // Output file will be overwritten when exists !!!
    {
        r=3;
        printf("cannot open output-file!\n");
    }
    else
    {
        while (!feof(in))
        {
            buff[0]=0;
            fgets(buff,max,in);

            for (i=0; i<max && buff[i] && buff[i]!='\r' && buff[i]!='\n' && (buff[i]==' ' || buff[i]=='\t'); i++);
            if (buff[i]=='#')
            {
                for (i=i+1;i<max && buff[i] && buff[i]!='\r' && buff[i]!='\n';i++)
                {
                    buff[i]=tolower(buff[i]);
                }
            }

            fputs(buff,out);
        }

        fclose(out);
        fclose(in);
    }

    return 0;
}

This is your code, can you spot the changes?
It also works fine!