Thread: help w/ file I/O

i'm trying to open a read a file that i wrote in notepad...it's a series of tables...four columns w/ five numbers in each...it should be rather simple but i can't even get it to read anything....even the first 5 floating values...let alone the whole database...and exit(1) will not work in a VMS system...but i can't figure out what else will....if anyone has any insight it's much appreciated...
#include <string.h>
void main (void)
{
FILE *in_file;
int i;
float val, n;
in_file = fopen("program.txt","r"); /*trying to open file*/

if (in_file == (FILE *) NULL)
{
printf("\nFailed to open the data file.\n");
exit(1);
}
printf("\nThe file has been successfully opened for reading.\n");

for (i = 1; i <= 5; i++)
{fscanf(in_file,"%0.2f %f", &n, &val);
printf("\n%0.2f %f", n, val);}
fclose(in_file);
}

i too your advice...and the exit thing works now...but it's still not reading the file whatsoever...but i wouldn't know that unless u helped me w/ that exit thing...thank you very much...i'll keep trying to get it to open....if u have anymore ideas then those will be much appreciated also...
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
void main (void)
{
FILE *in_file;
int i;
float val, n;
in_file = fopen("C:\\Directory\\program.txt", "r"); /*trying to open file*/

if (in_file == (FILE *) NULL)
{
printf("\nFailed to open the data file.\n");
exit(1);
}
printf("\nThe file has been successfully opened for reading.\n");

for (i = 1; i <= 5; i++)
{fscanf(in_file,"%0.2f", &n);
printf("\n%0.2f", n);}
fclose(in_file);
}

i registered for this board now...i got tired of seeing "Unregistered User" instead of my user name...though, my program still won't work...i've tinkered w/ it but have had no progress whatsoever w/ it....maybe i'm getting the pathway wrong...it stills says it's not open

I would change the part where you open the file to this:

if ((in_file = fopen(file_name, "r")) == NULL) {
fprintf(stderr, "***> Open error reading input file %s", file_name);
exit(-1);
} /* end if */

And as far as reading the file try doing something like this:
(I think you should be reading strings and not floating)

fgets(string_variable, 81, in_file);

while(! feof(in_file)) {
printf("%s", string_variable);
fgets(string_variable, 81, in_file);
} /* end while */

fclose(in_file);

The function fgets() breaks down like this:
fgets(string_variable, max_length_of_string, fileName);

Tell me if it works.

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
void main (void)
{
FILE *in_file;
int i;
float val,n;
char string_variable[81];
in_file = fopen("file:///C:/program.txt", "r"); /*trying to open file*/

if ((in_file = fopen(in_file, "r")) == NULL) {
fprintf(stderr, "***> Open error reading input file %s", in_file);
exit(-1);
} /* end if */


printf("\nThe file has been successfully opened for reading.\n");



fgets(string_variable, 81, in_file);

while(! feof(in_file)) {
printf("%s", string_variable);
fgets(string_variable, 81, in_file);
} /* end while */

fclose(in_file);
}

i might've not completely understood what you were doing in that code but i got the basic idea i believe...but it's giving me errors so i don't know if it works or not...maybe i just did it wrong or something

Code:

#include <stdio.h>

int main ( ) {
    char buff[BUFSIZ];
    FILE *fp;
    fp = fopen( "file.txt", "r" );
    while ( fgets(buff,BUFSIZ,fp) != NULL ) {
        int res;
        float val,n;
        res = sscanf( buff, "%f %f", &val, &n );
        if ( res == 2 ) {
            printf( "Success! - %f %f\n", val, n );
        } else {
            printf( "Garbage in line %s", buff );
        }
    }
    fclose( fp );
    return 0;
}

in_file = fopen("file:///C:/program.txt", "r"); /*trying to open file*/<======= This line is not needed.

Since it opens the file in the if statement below. Look at the if statement....there should be the exact filename where you open it up(if you open it up in the same folder as the program you just need the filename). I changed it so you can see the correct way.

if ((in_file = fopen("program.txt", "r")) == NULL) {
fprintf(stderr, "***> Open error reading input file %s", in_file);
exit(-1);
} /* end if */

but i didn't get that program to work w/ all of the tinkering that i had to do w/ it....it turns out that since i was doing that program in a VMS system that there was no way it would work at all....so, that sux...so, i had to delete all of the code that i was working on that was VMS specific and i started over w/ Microsoft Visual C++...and it works....i just need some adivce on how to make the output look like this....u don't have to do it for me...at the very least just help me w/ the partial code needed to do this and i can figure out the rest

needs to look like this:

Quantity On Reorder Minimum
Part No. Price Hand Point Order
0123 1.23 23 20 20
0234 2.34 34 50 25
3456 34.56 56 10 10
5678 6.78 7 75 25

any help at all will be much appreciated...as i've appreciated all of the help from the ppl on this board..thank you

/* Reading and printing a sequential file */
#include <stdio.h>

main()
{
int account;
float name;
int balance;
FILE *cfPtr; /* cfPtr = clients.dat file pointer */

if ((cfPtr = fopen("N:///CST/1110-1/TURNIN/s_virick/labtext.dat", "r")) == NULL)
printf("File could not be opened\n");
else {
printf("%-10s%-13s%s\n", "Part No.", "Price", "Quantity");
fscanf(cfPtr, "%d%f%d", &account, &name, &balance);

while (!feof(cfPtr)) {
printf("%-10d%-13f%7.2d\n", account, name, balance);
fscanf(cfPtr, "%d%f%d", &account, &name, &balance);
}

fclose(cfPtr);
}

return 0;
}


ok....so that's what i have so far....but there's a couple of things i gotta work out...