reading a file

**8ball** · 06-06-2004

my text.txt file

Code:

LDC 1,2 #444
LDC 1,2 #444

my program:

Code:

#include <stdio.h>
#include <string.h>
char file_array[10000];


void
readfile(char *file)
{
  char ch;
  int i = 0;
  FILE *pfile = fopen(file, "r");

  if (pfile == NULL)
     {
         puts("New Files");
     }
  else
     {
         while((ch = fgetc(pfile)) != EOF)
           {
               file_array[i] = ch;
               i++;
           }
         file_array[i] = '\0';
         fclose (pfile);
    }
}

int main(int argc, char **argv)
     
{
  char *filename = argv[1];
  //char test_string[50]="PRINT 1,2";
  char *sub_string;

  readfile(filename);
  printf("%s\n", strtok(file_array, " "));
  while ( (sub_string=strtok(NULL, ",")) != NULL)
  {
    printf("%s\n", sub_string);
  }
  return 0;
}

at the moment my output is

a.out text.txt
LDC
1
2 #444
LDC 1
2 #444

i want to modify it so it prints out this
LDC
1
2
LDC
1
2

ignoring everything after and including the #

how do i do this?

**Frobozz** · 06-07-2004

Give this a shot.

Code:

void
readfile(char *file)
{
  char ch;
  int i = 0;
  int comment = 0;
  FILE *pfile = fopen(file, "r");

  if (pfile == NULL)
	 {
		 puts("New Files");
	 }
  else
	 {
		 while((ch = fgetc(pfile)) != EOF)
		   {
			   if (ch == '#')
			   {
				 comment = 1;
			   }
			   else if (ch == '\n')
			   {
				 comment = 0;
			   }
 
			   if (comment == 0)
			   {
				  file_array[i] = ch;
				  i++;
			   }
		   }
		 file_array[i] = '\0';
		 fclose (pfile);
	}
}

**8ball** · 06-07-2004

when my input is
LDC 1,2 #444
LDC 1,2 # dkljdlkdj
Print -4 #dldkdl;

its giving me this output
LDC
1
2
LDC 1
2
Print -4

but i want it to be like this
LDC
1
2
LDC
1
2
Print
-4

**Salem** · 06-07-2004

Well first you need to read the file a line at a time, rather than reading the whole file into an array

Here are the first couple of steps

Code:

char buff[BUFSIZ];
while ( fgets( buff, BUFSIZ, pfile ) != NULL ) { /* read each line */
    char *hash = strchr( buff, '#' );  /* is there a comment? */
    if ( hash != NULL ) *hash = '\0'; /* line is now commentless */
    /* now do your strtok'ing */
}

**8ball** · 06-07-2004

will i need linked lists?

**pinko_liberal** · 06-07-2004

Originally Posted by 8ball

my text.txt file

Code:

LDC 1,2 #444
LDC 1,2 #444

my program:

Code:

  char ch;

         while((ch = fgetc(pfile)) != EOF)

Your code original code worked?

**8ball** · 06-07-2004

nope...

**pinko_liberal** · 06-07-2004

Originally Posted by 8ball

nope...

fgetc() returns an int, EOF is usually an int value that cannot be represented as a char, so you might end up with an infinite loop unless you declare ch as a int.

**8ball** · 06-07-2004

Originally Posted by Salem

Well first you need to read the file a line at a time, rather than reading the whole file into an array

Here are the first couple of steps

Code:

char buff[BUFSIZ];
while ( fgets( buff, BUFSIZ, pfile ) != NULL ) { /* read each line */
    char *hash = strchr( buff, '#' );  /* is there a comment? */
    if ( hash != NULL ) *hash = '\0'; /* line is now commentless */
    /* now do your strtok'ing */
}

where do i place this?

**8ball** · 06-07-2004

this is what my code looks like now

Code:

#include <stdio.h>
#include <string.h>
char file_array[10000];


/*void
readfile(char *file)
{
  char ch;
  int i = 0;
  FILE *pfile = fopen(file, "r");

  if (pfile == NULL)
     {
         puts("New Files");
     }
  else
     {
         while((ch = fgetc(pfile)) != EOF)
           {
	   	if (ch==35)
			break;
			else
			{
               file_array[i] = ch;
               i++;
	       }
           }
         file_array[i] = '\0';
         fclose (pfile);
    }
}
*/
void
readfile(char *file)
{
  int ch;
  int i = 0;
  int comment = 0;
  FILE *pfile = fopen(file, "r");

  if (pfile == NULL)
	 {
		 puts("New Files");
	 }
  else
	 {
		 while((ch = fgetc(pfile)) != EOF)
		   {
			   if (ch == '#')
			   {
				 comment = 1;
			   }
			   else if (ch == '\n')
			   {
				 comment = 0;
			   }
 
			   if (comment == 0)
			   {
				  file_array[i] = ch;
				  i++;
			   }
		   }
		 file_array[i] = '\0';
		 fclose (pfile);
	}
}

void breakup(char *file_array)
{
  

  	//char test_string[50]="PRINT 1,2";
  	char *sub_string;
	printf("%s\n", strtok(file_array, " "));
  	while ( (sub_string=strtok(NULL, ",")) != NULL)
  	{
    		printf("%s\n", sub_string);
  	}
}

int main(int argc, char **argv)
{
char *filename = argv[1];
  	readfile(filename);
  	breakup(file_array);
  	return 0;
}

and my output now is
LDC
1
2
LDC 1
2
Print -4

**Salem** · 06-07-2004

> where do i place this?
OK, the whole thing

Code:

int main ( int argc, char **argv ) {
    char buff[BUFSIZ];
    FILE *pfile = fopen(argv[1], "r");
    while ( fgets( buff, BUFSIZ, pfile ) != NULL ) { /* read each line */
        char *sub_string;
        char *hash = strchr( buff, '#' );  /* is there a comment? */
        if ( hash != NULL ) *hash = '\0'; /* line is now commentless */
        /* now do your strtok'ing */
        printf("%s\n", strtok(buff, " "));
        while ( (sub_string=strtok(NULL, ",\n")) != NULL)
        {
                printf("%s\n", sub_string);
        }
    }
    return 0;
}

**8ball** · 06-07-2004

thanks alot for that

what would be the parameter if i want to place all that in a function?

**8ball** · 06-07-2004

Code:

void breakup()
{
char buff[BUFSIZ];
    
    while ( fgets( buff, BUFSIZ, pfile ) != NULL ) { /* read each line */
        char *sub_string;
        char *hash = strchr( buff, '#' );  /* is there a comment? */
        if ( hash != NULL ) *hash = '\0'; /* line is now commentless */
        /* now do your strtok'ing */
        printf("%s\n", strtok(buff, " "));
        while ( (sub_string=strtok(NULL, ",\n")) != NULL)
        {
                printf("%s\n", sub_string);
        }
    }
}

int main ( int argc, char **argv ) {
  FILE *fp = fopen(argv[1], "r");
  breakup(fp);

  return 0;
}

is this the way to do it?

**Salem** · 06-07-2004

> is this the way to do it?
If you fix breakup() to accept a parameter, yes

**8ball** · 06-07-2004

void breakup(char *pfile)
?

Thread: reading a file

Thread Tools

Search Thread

Display

reading a file

Similar Threads

opening empty file causes access violation

Formatting the contents of a text file

airport Log program using 3D linked List : problem reading from file

Possible circular definition with singleton objects

System